FIELD OF THE INVENTION

The present invention relates to a method for preparing a biodegradable microcapsule and to a method for preparing a biodegradable microcapsule composition. The present invention also relates to the biodegradable microcapsule and the biodegradable microcapsule composition per se. The present invention also relates to uses of the biodegradable microcapsules and to methods involving the biodegradable microcapsule, including to prepare a consumer product. The present invention also relates to the consumer product per se.

BACKGROUND

Fragrance materials and flavour materials are employed in numerous consumer products to impart a particular sensory experience to the user, e.g. fragranced fabric conditioners for imparting a fragrance to washed laundry, or flavoured mouthwashes for freshening breath. However, most fragrance/flavour materials are volatile compounds and are unstable under conventional processing conditions, meaning that their effective incorporation into consumer products can be problematic.

Encapsulation techniques, which involve embedding the fragrance/flavour material in an external matrix, can be used to protect the fragrance/flavour material from its external surroundings (e.g. exposure to chemicals, air, light etc.). This allows the shelf life of the fragrance/flavour material to be prolonged such that it can be released when needed (e.g. upon breaking the encapsulate).

Complex coacervation is one such encapsulation technique, and is based upon the electrostatic interactions between two polymers of opposite charge. However, the processing conditions required, typically high temperatures and long reaction times, mean that whilst some fragrance/flavour materials will be successfully encapsulated, the more volatile species will be lost during the process. These conventional complex coacervation techniques also normally require a subsequent covalent cross-linking modification to be made to the coacervate in order to ensure its mechanical integrity. This cross-linking will have a detrimental effect on the biodegradability of the microencapsulate. Furthermore, despite their mechanical integrity, these microcapsules remain very porous resulting in fragrance and flavour materials easily diffuse out during storage into the air or the product they are incorporated into.

Other encapsulation techniques available commonly rely on the use of synthetic polymers to form a protective shell around the active ingredient via a polymerization process. Similar problems with the encapsulation of highly volatile species are also encountered with these techniques where the active must be kept at elevated temperatures for prolonged periods. Furthermore, synthetic polymer shell materials have inherently poor biodegradability and moreover can lead to the formation of microplastics, which are detrimental to the environment.

Biodegradable microcapsules can also be prepared at scale by spray drying of polysaccharides, for example, modified starches are widely used for this. Polysaccharides are however highly soluble in water and are unsuitable for use in aqueous products where they disintegrate rapidly provided no shelf-life protection for the active material. Alternatively, emulsion techniques have been used to prepare biodegradable microcapsules using proteins, for example, in EP 3967157 a triple emulsion process is used to encapsulate water-soluble actives within an oil phase and an outer protein hydrogel shell. Although this shell will be largely insoluble in water and so will have good mechanical stability in aqueous products it still has limited diffusion barrier properties and the active will leak out into the external phase. There is no posttreatment to limit the diffusion of the active out of the microcapsule.

Accordingly, there exists a need for a process to prepare biodegradable microcapsules, which can encapsulate fragrance materials and/or flavour materials having a broad range of volatilities and release them when required, and with good mechanical and diffusion stability.

SUMMARY OF THE INVENTION

Viewed from a first aspect, the present invention provides a method for preparing a biodegradable microcapsule, comprising:

(a) emulsifying a lipophilic phase comprising at least one fragrance material or flavour material in a plant-based protein solution comprising one or more plantbased protein(s) to give a primary emulsion, wherein said lipophilic phase is immiscible with said plant-based protein solution;

(b) re-emulsifying said primary emulsion in an external phase to give a secondary emulsion, wherein said external phase is immiscible with said primary emulsion; (c) inducing the plant-based protein(s) to undergo a sol-gel transition to from a plantbased protein hydrogel, wherein said plant-based protein hydrogel encapsulates said lipophilic phase to form a biodegradable microcapsule which is suspended in said external phase; and

(d) separating the external phase from the microcapsule; wherein said plant-based protein solution is at a temperature above the sol-gel transition temperature of the plant-based protein(s) during steps (a) and (b), further comprising subjecting the microcapsule to a post-treatment step, wherein the posttreatment step comprises a coating formation step, wherein the coating formation step comprises treating the microcapsule with a silicon-containing compound.

Viewed from a further aspect, the present invention provides a biodegradable microcapsule obtained by or obtainable by the method as hereinbefore described.

Viewed from a further aspect, the present invention provides a method for preparing a biodegradable microcapsule composition, comprising:

(a) emulsifying a lipophilic phase comprising a fragrance or a mixture of fragrances in a plant-based protein solution comprising one or more plant-based protein(s), wherein said lipophilic phase is immiscible with said plant-based protein solution, to give a primary emulsion;

(b) re-emulsifying said primary emulsion in an external phase to give a secondary emulsion, wherein said external phase is immiscible with said primary emulsion; and

(c) inducing the plant-based protein(s) to undergo a sol-gel transition to from a plantbased protein hydrogel, wherein said plant-based protein hydrogel encapsulates said lipophilic phase to form a biodegradable microcapsule which is suspended in said external phase; wherein said plant-based protein solution is at a temperature above the sol-gel transition temperature of the plant-based protein(s) during steps (a) and (b), further comprising subjecting the microcapsule to a post-treatment step, wherein the post-treatment step comprises a coating formation step, wherein the coating formation step comprises treating the microcapsule with a silicon-containing compound.

Viewed from a further aspect, the present invention provides a biodegradable microcapsule composition obtained by or obtainable by the method as hereinbefore described. Viewed from a further aspect, the present invention provides a biodegradable microcapsule comprising:

(a) a lipophilic phase comprising at least one fragrance material or flavour material; and

(b) a plant-based protein hydrogel comprising at least one plant-based protein(s); wherein: said plant-based protein hydrogel encapsulates said lipophilic phase; said plant-based protein hydrogel has a silicon-based coating deposited thereon; and the biodegradation percentage based upon O2 consumption of the plant-based protein hydrogel as measured according to ISO-14851 after 28 days is 60 to 100%.

Viewed from a further aspect, the present invention provides a composition comprising a biodegradable microcapsule as hereinbefore described and an external phase.

Viewed from a further aspect, the present invention provides a consumer product comprising a biodegradable microcapsule as hereinbefore described.

Viewed from a further aspect, the present invention provides a method of making a consumer product, comprising:

(a) preparing a biodegradable microcapsule according to the method as hereinbefore described;

(b) mixing said biodegradable microcapsule with a consumer product formulation.

Viewed from a further aspect, the present invention provides the use of a biodegradable microcapsule as hereinbefore described in a consumer product.

DEFINITIONS

As used herein, the term "fragrance" (used interchangeably with the term “perfume”) refers to the component of a formulation that is capable of imparting or modifying the odour of a product, such as a fabric conditioner or a hair conditioner, or a substrate such as fabric or hair. A fragrance is typically used to impart an overall pleasant odour or odour profile to a product either to provide a pleasurable experience, such as a Fine Fragrance, or to provide sensory cues as to the product’s benefit and function, such as a calming effect for a lavender sleep aid, the idea of cleanliness for a laundry product, or to mask an unpleasant odour, such as in an insect repellent product. A “fragrance” may be composed of one or more components that can be a single chemical entity, referred to herein as a “fragrance material” (used interchangeably with the term “perfume material”), or a mixture of different “fragrance materials”. Fragrance materials can be created by either synthetic processes or extracted from nature, particularly plants, to obtain naturally occurring plant essential oils and plant extracts such as orange oil. Fragrance materials created by synthetic processes can be either new-to-the-world chemicals or nature-identical fragrance materials. Synthetic and naturally derived fragrance materials can then be blended into fragrances by skilled perfumers, also called noses, for use in consumer products. Fragrance materials can be obtained from specialist fragrance suppliers, known as fragrance houses, as individual chemicals, natural blends or as proprietary specialty blends where the full composition is not disclosed. The individual fragrance materials which comprise a known natural blend can be found by reference to Journals commonly used by those skilled in the art such as "Perfume and Flavourist" or "Journal of Essential Oil Research", or listed in reference texts such as the book by S. Arctander, Perfume and Flavor Chemicals, 1969, Montclair, New Jersey, USA and more recently re-published by Allured Publishing Corporation Illinois (1994) and "Perfume and Flavour Materials of Natural Origin", S. Arctander, Ed., Elizabeth, N.J., 1960. It will be understood that for the purposes of this invention, a “fragrance material” includes a pro-fragrance such as an acetal pro-fragrance, ketal profragrance, ester pro-fragrance, hydrolysable inorganic-organic pro-fragrance, and combinations thereof. The fragrance materials may be released from the pro-fragrances in a number of ways, for example, by hydrolysis, or by a shift in an equilibrium reaction, or by a pH-change, or by enzymatic release, or by UV-radiation.

A fragrance material can be described in terms of its odour strength, detection threshold, odour saturation and its character. In fragrance encapsulates it is preferable to use fragrance materials with a low odour detection threshold and a high strength so as to maximise the noticeability of even small levels of fragrance encapsulated and released.

In order to impart an odour, a fragrance material must be volatile, even if only to a small degree, as it is necessary for the molecule to be airborne to enter the nose, where it gets attached to specific neuroreceptors and elicits a signal within the olfactory system. Fragrance materials can be classified according to their volatility. Preferably fragrance materials are liquid at 20°C and atmospheric pressure but occasionally they may be solid and can be blended with other liquid fragrance materials or solvents. Typically, the fragrance industry refers to the volatility and substantivity by loosely categorising materials into one of 3 categories: base notes for the least volatile and most substantive, heart notes for those of moderate volatility and substantivity and top notes for the most volatile and least substantive. This is based on the odour perception of the materials and is quite subjective. One way of objectively classifying the volatility of fragrance materials is according to their vapour pressure.

As used herein, the term "vapour pressure" means the partial pressure in air at a defined temperature (e.g., 25°C) and standard atmospheric pressure (760 mmHg) for a given chemical species. It defines a chemical species' affinity for the gas phase rather than the liquid or solid state. The higher the vapour pressure the greater the proportion of the material that will, at equilibrium, be in a closed headspace. It is also related to the rate of evaporation of a fragrance material which is defined in an open environment where the material is leaving the system. The vapour pressure can be readily determined according to the reference program ACD/Percepta Desktop Software, Version 14.0 (Build: Aug/26/2021), Advanced Chemistry Development, Inc (ACD/Labs), Toronto, Canada, www.acdlabs.com.

A physical parameter that is relevant to the encapsulation of a fragrance material is its hydrophobicity, which may be defined in terms of its partition coefficient P. As used herein, the term "partition coefficient" refers to the ratio between the equilibrium concentration of that substance in n-octanol and in water, and is a measure of the differential solubility of said substance between these two solvents. As used herein, the term “logP” refers to the logarithm to the base 10 of the partition coefficient P. The logP can be readily determined according to the reference program ACD/Percepta Desktop Software, Version 14.0 (Build: Aug/26/2021), Advanced Chemistry Development, Inc (ACD/Labs), Toronto, Canada, www.acdlabs.com LogP values are predicted from the SMILE string of fragrance materials molecules. Three different types of logP values can be selected from the software. The logP Classic is based on an algorithm which takes into account a database of experimental logP values while using the principal of isolating carbons. The logP GALAS is based on an algorithm taking into account a database of a training set of compounds as well as adjusting the values with data from structurally close compounds. The consensus logP is a model based on the previous two algorithms, which can be expressed as: consensus logP = a x logP Classic + b x logP GALAS, where a and b are coefficients of the model. The latter value, consensus logP, is the logP value indicated herein.

Another aspect that is relevant to the encapsulation of a fragrance material is its Hansen Solubility Parameters (HSPs). The term HSP refers to a solubility parameter approach proposed by Charles Hansen first used to predict polymer solubility in a given solvent as described in, The Three Dimensional Solubility Parameter and Solvent Diffusion Coefficient, by Charles Hansen, Danish Technical Press (Copenhagen, 1967). This approach has since been reapplied to many other molecules. The fragrance material (or flavour material or solvent) and its interactions with its environment are defined by 3 forces: atomic dispersion forces, molecular permanent dipole forces, and molecular hydrogen bonding forces. Materials with similar HSP parameters are more likely to be miscible. These forces can be quantified by 3 values: 5D, the Hansen dispersion value which relates to the Van der Waals interactions (intermolecular forces); 5P, the Hansen polarity value which relates to the dipole moment (electrical charges); and 5H, the Hansen Hydrogen-bonding ("h-bonding") value. The solubility parameter 5 (MPa ^1/2 ) is defined as 5 ² = 5D ² + 5P ² + 5H ² = E/V, where E is the cohesive energy of a solvent and V is the molar volume. The HSP values for a given material can be obtained from the HSPiP (Hansen Solubility Parameters in Practice) software available from www.hansen-solubility.com through two main different ways. Those values can either be retrieved from the Master Dataset, which comprises over 20,000 materials, by searching by name or CAS number; or be predicted by entering the SMILE string of a given molecule in the DIY section of the software, using the Y-MB (Yamamoto-Molecular Breaking) method. Furthermore, the determination of the HSP sphere relative to a given fragrance material is a good way to predict the solubility preferences within a blend of fragrance materials. The radius Ro of the HSP sphere is defined as Ro = Ra/RED, where Ra is the HSP distance between two molecules (1 and 2) expressed by: Ra ² = 4 (5DI - 5D ₂ ) ² + (6PI - 5 _P2 ) ² + (5HI - 5H ₂ ) ² , and RED is the Relative Energy Difference. This RED value can also be extracted from or predicted through the HSPiP software, and a good solvent for a given material should exhibit a RED value lower or equal to 1 , whereas a solvent displaying a RED value greater than 1 should be considered as a bad solvent for the given material.

A fragrance material may be selected from an alcohol, an aldehyde, a ketone, an ester, an ether, an acetate, an alkene, a nitrile, a nitrogenous heterocyclic compound, a sulfurous heterocyclic compound, and a Schiff base.

Preferred aldehyde fragrance materials include, without limitation, alpha- amylcinnamaldehyde, anisic aldehyde, decyl aldehyde, lauric aldehyde, methyl n-nonyl acetaldehyde, methyl octyl acetaldehyde, nonylaldehyde, benzenecarboxaldehyde, neral, geranial, 1 ,1-diethoxy-3,7-dimethylocta-2,6-diene, 4-isopropylbenzaldehyde, 2,4- dimethyl-3-cyclohexene-1-carboxaldehyde, alpha-methyl-p- isopropyldihydrocinnamaldehyde, 3-(3-isopropylphenyl) butanal, alpha- hexylcinnamaldehyde, 7-hydroxy-3,7-dimethyloctan-1-al, 2,4-dimethyl-3-cyclohexene- 1-carboxaldehyde, octyl aldehyde, phenylacetaldehyde, 2,4-dimethyl-3-cyclohexene-1- carboxaldehyde, hexanal, 3,7-dimethyloctanal, 6,6-dimethylbicyclo[3.1.1]hept-2-ene-2- butanal, nonanal, octanal, 2-nonenal undecenal, 2-methyl-4-(2,6,6-trimethyl-1- cyclohexenyl-1)-2-butenal, 2,6-dimethyloctanal, 3-(p-isopropylphenyl)propionaldehyde, 3-phenyl-4-pentenal citronellal, o/p-ethyl-alpha, alpha, 9-decenal, dimethyldihydrocinnamaldehyde, p-isobutyl-alphamethylydrocinnamaldehyde, cis-4- decen-1-al, 2,5-dimethyl-2-ethenyl-4-hexenal, trans-2-methyl-2-butenal, 3- methylnonanal, alpha-sinensal, 3-phenylbutanal, 2,2-dimethyl-3- phenylpropionaldehyde, m-tertbutyl-alpha-methyldihydrocinnamic aldehyde, geranyl oxyacetaldehyde, trans-4-decen-1-al, methoxycitronellal, and mixtures thereof.

Preferred ester fragrance materials include, without limitation, allyl cyclohexanepropionate, allyl heptanoate, allyl amyl glycolate, allyl caproate, amyl acetate (n-pentyl acetate), amyl propionate, benzyl acetate, benzyl propionate, benzyl salicylate, cis-3- hexenylacetate, citronellyl acetate, citronellyl propionate, cyclohexyl salicylate, dihydro isojasmonate, dimethyl benzyl carbinyl acetate, ethyl acetate, ethyl acetoacetate, ethyl butyrate, ethyl-2-methyl butryrate, ethyl-2-methyl pentanoate, fenchyl acetate (1 ,3,3- trimethyl-2-norbornanyl acetate), tricyclodecenyl acetate, tricyclodecenyl propionate, geranyl acetate, cis-3-hexenyl isobutyrate, hexyl acetate, cis-3-hexenyl salicylate, n- hexyl salicylate, isobornyl acetate, linalyl acetate, para-tertiary-butyl cyclohexyl acetate, (-)-L-menthyl acetate, ortho-tertiary-butylcyclohexyl acetate, methyl benzoate, methyl dihydro isojasmonate, alpha-methylbenzyl acetate, methyl salicylate, 2-phenylethyl acetate, prenyl acetate, cedryl acetate, cyclabute, phenethyl phenylacetate, terpinyl formate, citronellyl anthranilate, ethyl tricyclo[5.2.1.0-2,6]decane-2-carboxylate, n-hexyl ethyl acetoacetate, 2-tertbutyl-4-methyl cyclohexyl acetate, formic acid, 3,5,5- trimethylhexyl ester, phenethyl crotonate, cyclogeranyl acetate, geranyl crotonate, ethyl geranate, geranyl isobutyrate, 3,7-dimethyl-ethyl 2-nonynoate-2,6-octadienoic acid methyl ester, citronellyl valerate, 2-hexenylcyclopentanone, cyclohexyl anthranilate, L- citronellyl tiglate, butyl tiglate, pentyl tiglate, geranyl caprylate, 9-decenyl acetate, 2- isopropyl-5-methylhexyl-1 butyrate, n-pentyl benzoate, 2-methylbutyl benzoate (and mixtures thereof with pentyl benzoate), dimethyl benzyl carbinyl propionate, dimethyl benzyl carbinyl acetate, trans-2-hexenyl salicylate, dimethyl benzyl carbinyl isobutyrate, 3,7-dimethyloctyl formate, rhodinyl formate, rhodinyl isovalerate, rhodinyl acetate, rhodinyl butyrate, rhodinyl propionate, cyclohexylethyl acetate, neryl butyrate, tetrahydrogeranyl butyrate, myrcenyl acetate, 2,5-dimethyl-2-ethenylhex-4-enoic acid, methyl ester, 2,4-dimethylcyclohexane-1-methyl acetate, ocimenyl acetate, linalyl isobutyrate, 6-methyl-5-heptenyl-1 acetate, 4-methyl-2-pentyl acetate, n-pentyl 2- methylbutyrate, propyl acetate, isopropenyl acetate, isopropyl acetate, 1- methylcyclohex-3-ene-carboxylic acid, methyl ester, propyl tiglate, propyl/isobutyl cyclopent-3-enyl-1 -acetate (alphavinyl), butyl 2-furoate, ethyl 2-pentenoate, (E)-methyl 3-pentenoate, 3-methoxy-3-methylbutyl acetate, n-pentyl crotonate, n-pentyl isobutyrate, propyl formate, furfuryl butyrate, methyl angelate, methyl pivalate, prenyl caproate, furfuryl propionate, diethyl malate, isopropyl 2-methylbutyrate, dimethyl malonate, bornyl formate, styralyl acetate, 1-(2-furyl)-1 -propanone, l-citronellyl acetate,

3.7-dimethyl-1 ,6-nonadien-3-yl acetate, neryl crotonate, di hydromyrcenyl acetate, tetrahydromyrcenyl acetate, lavandulyl acetate, 4-cyclooctenyl isobutyrate, cyclopentyl isobutyrate, 3-methyl-3-butenyl acetate, allyl acetate, geranyl formate, cis-3-hexenyl caproate, and mixtures thereof.

Preferred alcohol fragrance materials include, without limitation, benzyl alcohol, beta-gam ma-hexenol (2-hexen-1-ol), cedrol, citronellol, cinnamic alcohol, p-cresol, cumic alcohol, dihydromyrcenol, 3,7-dimethyl-1-octanol, dimethyl benzyl carbinol, eucalyptol, eugenol, fenchyl alcohol, geraniol, hydratopic alcohol, isononyl alcohol (3,5,5-trimethyl-1-hexanol), linalool, methyl chavicol (estragole), methyl eugenol (eugenyl methyl ether), nerol, 2-octanol, patchouli alcohol, phenyl hexanol (3-methyl-5- phenyl-1 -pentanol), phenethyl alcohol, alpha-terpineol, tetrahydrolinalool, tetrahydromyrcenol, 4-methyl-3-decen-5-ol, l-3,7-dimethyloctane-1-ol, 2-(furfuryl-2)- heptanol, 6,8-dimethyl-2-nonanol, ethyl norbornyl cyclohexanol, beta-methyl cyclohexane ethanol, 3,7-dimethyl-(2),6-octen(adien)-1-ol, trans-2-undecen-1-ol, 2- ethyl-2-prenyl-3-hexenol, isobutyl benzyl carbinol, dimethyl benzyl carbinol, ocimenol,

3.7-dimethyl-1 ,6-nonadien-3-ol (cis & trans), tetrahydromyrcenol, alpha-terpineol, 9- decenol-1 , 2-(2-hexenyl)-cyclopentanol, 2,6-dimethyl-2-heptanol, 3-methyl-1-octen-3-ol, 2,6-dimethyl-5-hepten-2-ol, 3,7,9-trimethyl-1,6-decadien-3-ol, 3,7-dimethyl-6-nonen-1- ol, 3,7-dimethyl-1-octyn-3-ol, 2,6-dimethyl-1 ,5,7-octatrienol-3, dihydromyrcenol, 2,6,- trimethyl-5,9-undecadienol, 2,5-dimethyl-2-propylhex-4-enol-1, (Z)-3-hexenol, o,m,p- methyl-phenylethanol, 2-methyl-5-phenyl-1-pentanol, 3-methylphenethyl alcohol, paramethyl dimethyl benzyl carbinol, methyl benzyl carbinol, p-methylphenylethanol, 3,7- dimethyl-2-octen-1-ol, 2-methyl-6-methylene-7-octen-4-ol, and mixtures thereof.

Preferred ketone fragrance materials include, without limitation, oxacycloheptadec- 10-en-2-one, benzylacetone, benzophenone, L-carvone, cisjasmone, 4-(2,6,6-trimethyl-3-cyclohexen-1-yl)-but-3-en-4-one, ethyl amyl ketone, alpha-ionone, ionone beta, ethanone, octahydro-2, 3,8, 8-tetramethyl-2- acetonaphthalene, alpha-irone, 1-(5,5-dimethyl-1-cyclo-hexen-1-yl)-4-penten-1-one, 3- nonanone, ethyl hexyl ketone, menthone, 4-methyl-acetophenone, gamma-methyl ionone, methyl pentyl ketone, methyl heptenone (6-methyl-5-hepten-2-one), methyl heptyl ketone, methyl hexyl ketone, delta muscenone, 2-octanone, 2-pentyl-3-methyl-2- cyclopenten-1-one, 2-heptylcyclopentanone, alpha-methylionone, 3-methyl-2-(trans-2- pentenyl)-cyclopentenone, octenyl cyclopentanone, n-amylcyclopentenone, 6-hydroxy- 3,7-dimethyloctanoic acid lactone, 2-hydroxy-2-cyclohexen-1-one, 3-methyl-4-phenyl-3- buten-2-one, 2-pentyl-2,5,5-trimethylcyclopentanone, 2-cyclopentylcyclopentanol-1 , 5- methylhexan-2-one, gamma-dodecalactone, delta-dodecalactone, gamma-nonalactone, delta-nonalactone, gamma-octalactone, delta-undecalactone, gamma-undecalactone, alpha damascene, beta damascene, gamma damascene, delta damascene and mixtures thereof.

Preferred ether fragrance materials include, without limitation, diphenyl oxide, p- cresyl methyl ether, 4,6,6,7,8,8-hexamethyl-1 ,3,4,6,7,8-hexahydro-cyclopenta(G)-2- benzopyran, beta-naphthyl methyl ether, methyl isobutenyl tetrahydropyran, 5-acetyl- 1 , 1 ,2,3,3,6-hexamethylindan (phantolide), 7-acetyl-1 , 1 ,3,4,4,6-hexamethyltetralin (tonalid), 2-phenylethyl-3-methylbut-2-enyl ether, ethyl geranyl ether, phenylethyl isopropyl ether, and mixtures thereof.

Preferred alkene fragrance materials include, without limitation, allo-ocimene, camphene, beta-caryophyllene, cadinene, diphenylmethane, d-limonene, lymolene, beta-myrcene, para-cymene, 2-alpha-pinene, beta-pinene, alpha-terpinene, gammaterpinene, terpineolene, 7-methyl-3-methylene-1 ,6-octadiene, and mixtures thereof.

Preferred nitrile fragrance materials include, without limitation, 3,7-dimethyl-6- octenenitrile, 3,7-dimethyl-2(3), 6-nonadienenitrile, (2E,6Z)-2,6-nonadienenitrile, n- dodecane nitrile, and mixtures thereof.

Preferred Schiff base fragrance materials include, without limitation, citronellyl nitrile, nonanal/methyl anthranilate, N-octylidene-anthranilic acid methyl ester, hydroxycitronellal/methyl anthranilate, cyclamen aldehyde/methyl anthranilate, methoxyphenylpropanal/methyl anthranilate, ethyl p-aminobenzoate/hydroxycitronellal, citral/methyl anthranilate, 2,4-dimethylcyclohex-3-enecarbaldehyde methyl anthranilate, hydroxycitronellal-indole, and mixtures thereof.

As used herein, the term “low volatility fragrance material” is classified as a fragrance material having a vapour pressure less than 0.001 Torr (0.000133 kPa) at 25°C. As used herein, the term “moderate volatility fragrance material” is classified as a fragrance material having a vapour pressure greater than or equal to 0.001 Torr (0.000133 kPa) at 25°C but less than 0.1 Torr (0.0133 kPa) at 25°C.

As used herein, the term “high volatility fragrance material” is classified as one having a vapour pressure greater than or equal to 0.1 Torr (0.0133 kPa) at 25°C.

As used herein, the term "flavour" refers to the component of a formulation that is capable of imparting or modifying the taste and smell of a product, such as a toothpaste or foodstuff. A flavour is typically used to impart an overall pleasant taste and smell, or a taste and smell profile, to a product either to simply provide a pleasurable experience, such as in a foodstuff, or to mask an unpleasant taste or smell, such as in a medicine. A flavour or flavour material can be described in terms of its aroma strength, detection threshold and quality. A “flavour” may be composed of one or more components that can be a single chemical entity, referred to herein as a “flavour material”, or a mixture of different “flavour materials”. Flavour materials can be created by either synthetic processes or extracted from nature, particularly from plants, to create naturally occurring plant and animal oils and exudate, such as vanilla. Synthetic and naturally derived flavour materials can then be blended into flavours by skilled flavourists for use in consumer products. Flavour materials can be obtained from specialist flavour suppliers, known as flavour houses, as individual chemicals, natural blends or as proprietary specialty blends where the full composition is not disclosed. The individual flavour materials which comprise a known natural blend can be found by reference to Journals commonly used by those skilled in the art such as "Perfume and Flavourist" or "Journal of Essential Oil Research", or listed in reference texts such as the book by S. Arctander, Perfume and Flavor Chemicals, 1969, Montclair, New Jersey, USA and more recently re-published by Allured Publishing Corporation Illinois (1994); "Perfume and Flavour Materials of Natural Origin", S. Arctander, Ed., Elizabeth, N.J., 1960; and "Flavourings", E. Ziegler and H. Ziegler (ed.), Wiley-VCH Weinheim, 1998. It will be understood that flavours can be volatile or have volatile components which are detected by the nose in the same way as fragrances. As such, flavour materials can also be classified according to their physical characteristics, such as volatility and hydrophobicity, using the methods described above for fragrance materials. Flavour materials can also be described according to their Hansen Solubility Parameters using the methods described above for fragrance materials.

Sources of flavour materials include essential oils, concretes, absolutes, resins, resinoids, balsams, and tinctures. Preferred flavour materials include anise oil, ethyl-2- methyl butyrate, vanillin, cis-3-heptenol, cis-3-hexenol, trans-2-heptenal, butyl valerate, 2,3-diethyl pyrazine, methylcyclo-pentenolone, benzaldehyde, valerian oil,

3.4-dimeth-oxyphenol, amyl acetate, amyl cinnamate, y-butyryl lactone, trimethyl pyrazine, phenyl acetic acid, isovaleraldehyde, ethyl maltol, ethyl vanillin, ethyl valerate, ethyl butyrate, cocoa extract, coffee extract, peppermint oil, spearmint oil, clove oil, anethol, cardamom oil, Wintergreen oil, cinnamic aldehyde, ethyl-2-methyl valerate, g-hexenyl lactone, 2,4-decadienal, 2,4-heptadienal, methyl thiazole alcohol (4-methyl-5-b-hydroxyethyl thiazole), 2-methyl butanethiol, 4-mercapto-2-butanone, 3-mercapto-2-pentanone, 1 -mercapto-2-propane, benzaldehyde, furfural, furfuryl alcohol, 2-mercapto propionic acid, alkyl pyrazine, methyl pyrazine, 2-ethyl-3-methyl pyrazine, tetramethyl pyrazine, polysulfides, dipropyl disulphide, methyl benzyl disulphide, alkyl thiophene, 2,3-dimethyl thiophene, 5-methyl furfural, acetyl furan,

2.4-decadienal, guiacol, phenyl acetaldehyde, b-decalactone, d-limonene, acetoin, amyl acetate, maltol, ethyl butyrate, levulinic acid, piperonal, ethyl acetate, n-octanal, n-pentanal, n-hexanal, diacetyl, monosodium glutamate, monopotassium glutamate, sulfur-containing amino acids, e.g., cysteine, 2-methylfuran-3-thiol, 2- methyldihydrofuran-3-thiol, 2,5-dimethylfuran-3-thiol, tetramethyl pyrazine, propylpropenyl disulphide, propylpropenyl trisulfide, diallyl disulphide, diallyl trisulfide, dipropenyl disulphide, dipropenyl trisulfide, 4-methyl-2-[(methylthio)-ethyl]- 1 ,3-dithiolane, 4,5-dimethyl-2-(methylthiomethyl)-1 ,3-dithiolane, and 4-methyl-2- (methylthiomethyl)-l ,3- dithiolane, hop oils, and citrus oils such as lemon, orange, lime, grapefruit,

As used herein, the term “low volatility flavour material” is classified as a flavour material having a vapor pressure less than 0.001 Torr (0.000133 kPa) at 25 °C.

As used herein, the term “moderate volatility flavour material” is classified as a flavour material having a vapour pressure greater than or equal to 0.001 Torr (0.000133 kPa) at 25°C but less than 0.1 Torr (0.0133 kPa) at 25°C.

As used herein, the term “high volatility flavour material” is classified as a flavour material having a vapour pressure greater than or equal to 0.1 Torr (0.0133 kPa) at25°C.

As used herein, the term “lipophilic phase” refers to a phase comprising at least one fragrance material or flavour material, which is immiscible with a plant-based protein solution as described herein.

As used herein, the term “oil-miscible solvent” refers to a substance that is capable of dissolving the at least one fragrance or flavour material. As used herein, the term “primary emulsion” refers to a system wherein a lipophilic phase is emulsified in an immiscible aqueous plant-based protein solution.

As used herein, the term “secondary emulsion” refers to a primary emulsion, which has itself been emulsified in a further immiscible external phase.

As used herein, the term “core-shell microcapsule” refers to a microcapsule having a central core that is a lipophilic phase, wherein the lipophilic phase is surrounded by a plant-based protein hydrogel in the form of a shell.

As used herein, the term “multicore morphology” is used to describe a core-shell microcapsule wherein the lipophilic phase is in the form of a plurality of droplets.

As used herein, the term “single core morphology” is used to describe a coreshell microcapsule wherein the lipophilic phase is in the form of a single droplet.

As used herein, the term “matrix microcapsule” refers to a microcapsule comprised of a plant-based protein hydrogel matrix in which a lipophilic phase has been dispersed throughout.

As used herein, the term “standard fabric conditioner formulation” refers to a fabric conditioner having the composition described in Table 1 in the Examples section.

As used herein, the term “sol-gel transition temperature” refers to the temperature at which a plant-based protein transforms from a liquid state into a hydrogel state. Thus, at temperatures above the sol-gel transition temperature, the plant-based protein will be in a liquid state, and at temperatures below the sol-gel transition temperature the plantbased protein will be in a hydrogel state.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to a method for preparing a biodegradable microcapsule, comprising:

(a) emulsifying a lipophilic phase comprising at least one fragrance material or flavour material in a plant-based protein solution comprising one or more plantbased protein(s) to give a primary emulsion, wherein said lipophilic phase is immiscible with said plant-based protein solution;

(b) re-emulsifying said primary emulsion in an external phase to give a secondary emulsion, wherein said external phase is immiscible with said primary emulsion;

(c) inducing the plant-based protein(s) to undergo a sol-gel transition to from a plantbased protein hydrogel, wherein said plant-based protein hydrogel encapsulates said lipophilic phase to form a biodegradable microcapsule which is suspended in said external phase; and

(d) separating the external phase from the microcapsule; wherein said plant-based protein solution is at a temperature above the sol-gel transition temperature of the plant-based protein(s) during steps (a) and (b), further comprising subjecting the microcapsule to a post-treatment step, wherein the posttreatment step comprises a coating formation step, wherein the coating formation step comprises treating the microcapsule with a silicon-containing compound.

Any suitable plant-based proteins may be used in the present invention. In preferred methods of the present invention, the plant-based protein(s) is obtained from fava bean, mung bea, pea, rice, potato, rapeseed, lentil, chickpea, sunflower seed, pumpkin seed, flax, chia, canola, lupine, alfalfa, moringa, wheat, corn zein or sorghum; preferably the plant protein(s) is selected from pea protein, potato protein, rapeseed protein, lentil protein, chickpea protein, fava bean protein, mung bean protein, sunflower seed protein, pumpkin seed protein, flax protein, chia protein, canola protein, lupine protein, alfalfa protein, moringa protein and/or rice protein, more preferably pea protein and/or potato protein. Such proteins are considered to be low allergenicity proteins.

Suitable plant-based proteins further include:

Brassicas: including Brassica balearica: Mallorca cabbage, Brassica carinata: Abyssinian mustard or Abyssinian cabbage, Brassica elongata: elongated mustard, Brassica fruticulosa: Mediterranean cabbage, Brassica hilarionis: St Hilarion cabbage, Brassica juncea: Indian mustard, brown and leaf mustards, Sarepta mustard, Brassica napus: rapeseed, canola, rutabaga, Brassica narinosa: broadbeaked mustard, Brassica nigra: black mustard, Brassica oleracea: kale, cabbage, collard greens, broccoli, cauliflower, kai-lan, Brussels sprouts, kohlrabi, Brassica perviridis: tender green, mustard spinach, Brassica rapa (syn. B. campestris): Chinese cabbage, turnip, rapini, komatsuna, Brassica rupestris: brown mustard, Brassica tournefortii: Asian mustard

Solanaceae: including tomatoes, potatoes, eggplant, bell and chili peppers; cereals: including maize, rice, wheat, barley, sorghum, millet, oats, rye, triticale, fonio; pseudocereals: including amaranth (love-lies-bleeding, red amaranth, prince-of- Wales-feather), breadnut, buckwheat, chia, cockscomb (also called quail grass or soko), pitseed Goosefoot, qahiwa, quinoa and, wattleseed (also called acacia seed); Legume: including Acacia alata (Winged Wattle), Acacia decipiens, Acacia saligna (commonly known by various names including coojong, golden wreath wattle, orange wattle, blue-leafed wattle), Arachis hypogaea (peanut), Astragalus galegiformis, Cytisus laburnum (the common laburnum, golden chain or golden rain), Cytisus supinus, Dolichios lablab (common names include hyacinth bean, lablab-bean bonavist bean/pea, dolichos bean, seim bean, lablab bean, Egyptian kidney bean, Indian bean, bataw and Australian pea.), Ervum lens (Lentil), Genista tinctorial (common names include dyer's whin, waxen woad and waxen wood), Glycine max (Soybean), Lathyrus clymenum (peavines or vetchlings), Lathyrus odoratus (peavines or vetchlings), Lathyrus staivus (peavines or vetchlings), Lathyrus Silvetris (peavines or vetchlings), Lotus tetragonolobus (asparagus-pea or winged pea), Lupinus albus (Lupin), Lupinus angustifolius (lupin), Lupinus luteus (Lupin), Lupinus polyphyllus (Lupin), Medicago sativa (Alfalfa), Phaseolus aureus (Mung bean), Phaseolus coccineus (Runner bean), Phaseolus nanus (Green bean I French bean), Phaseolus vulgaris (Green bean I French bean), Pisum sativum (pea), Trifolium hybridum (Clover), Trifolium pretense (Red clover), Vicia faba (Broad bean), Vicia sativa (Vetch), Vigna unguiculate (cowpea)

Non-Legumes: including: Acanshosicyos horrida (Acanshosicyos horrida), Aesculus hyppocastanum (Conker tree I Horsechestnut), Anacardium occidentale (Cashew tree), Balanites aegyptica, Bertholletia excels (Brazil nut), Beta vulgaris (Sugar beet), Brassica napus (Rapeseed), Brassica juncea (Brown mustard), Brassica nigra (Black mustard), Brassica hirta (Eurasian mustard), Cannabis sativa (marijuana), Citrullus vulgaris (Sort of watermelon), Citrus aurantiaca (Citrus), Cucurbita maxima (squash), Fagopyrum esculentum (knotweed), Gossypium barbadense (Extra-long staple cotton), Heianthus annuus (sunflower), Nicotiana sp. (Tobacco plant), Prunus avium (cherry), Prunus cerasus (Sour cherry), Prunus domestica (plum), Prunus amygdalus (almond), Ricinus communis (Caster bean I caster oil plant), Sasamum indicum (Sesame), Sinapis alba (White mustard), Terlfalrea pedata (Oyster nut).

For the avoidance of doubt, the plant-based microcapsules of the present invention do not encompass plants in their natural state, e.g. naturally formed plant cells, organelles or vesicles are not plant-based microcapsules of the present invention.

In preferred methods of the present invention, the at least one fragrance material or flavour material is selected from an alcohol, an aldehyde, a ketone, an ester, an ether, an acetate, an alkene, a nitrile, a nitrogenous heterocyclic compound, a sulfurous heterocyclic compound, and a Schiff base.

The fragrance materials and flavour materials employed in the present invention may be of natural origin (i.e. they are extracted from a natural source and are not synthetically modified in any way). Preferred fragrance materials or flavour materials of natural origin include nutmeg extract, cardamon extract, ginger extract, cinnamon extract, patchouli oil, geranium oil, orange oil, mandarin oil, orange flower extract, cedarwood, vetyver, lavandin, ylang extract, tuberose extract, sandalwood oil, bergamot oil, rosemary oil, spearmint oil, peppermint oil, lemon oil, lavender oil, citronella oil, chamomile oil, clove oil, sage oil, neroli oil, labdanum oil, eucalyptus oil, verbena oil, mimosa extract, narcissus extract, jasmine extract, olibanum extract, rose extract, vanillin, coffee extract, hop oil or combinations thereof. Preferably, the fragrance materials or flavour materials of natural origin are plant-derived. The fragrance materials or flavour materials of natural origin may be used alone, or in combination, or in combination with synthetic fragrance materials.

In preferred methods of the present invention, the at least one fragrance material or flavour material has a vapour pressure of greater than or equal to 0.0001 Torr at 25°C, preferably greater than or equal to 0.001 Torr at 25°C.

In preferred methods of the present invention, the at least one fragrance material or flavour material has a logP greater than or equal to 3.0.

In preferred methods of the present invention, the at least one fragrance material or flavour material has at least two Hansen solubility parameters selected from: an atomic dispersion force (5D) from 14 to 20, a dipole moment (5P) of less than 8, and a hydrogen bonding (5H) from 2.5 to 11 .

In preferred methods of the present invention, the at least one fragrance material or flavour material is part of a fragrance or flavour.

Preferably, the fragrance or flavour contains at least 20 wt% of fragrance material(s) or flavour material(s) with a vapour pressure greater than or equal to 0.001 Torr at 25°C based upon the total weight of the fragrance or flavour, more preferably 40 wt%, more preferably 60 wt%.

Preferably, the fragrance or flavour contains at least 20 wt% of fragrance material(s) or flavour material(s) with a logP greater than 3.0 based upon the total weight of the fragrance or flavour, more preferably greater than 3.5, more preferably greater than 4.0. Preferably, the fragrance or flavour contains at least 40 wt% of fragrance material(s) or flavour material(s) with a logP greater than 3.0 based upon the total weight of the fragrance or flavour, more preferably greater than 3.5, more preferably greater than 4.0.

Preferably, the fragrance or flavour contains at least 50 wt% of fragrance material(s) or flavour material(s) with a logP greater than 3.0 based upon the total weight of the fragrance or flavour, more preferably greater than 3.5, more preferably greater than 4.0.

Preferably, the fragrance or flavour contains at least 60 wt% of fragrance material(s) or flavour material(s) with a logP greater than 3.0 based upon the total weight of the fragrance or flavour, more preferably greater than 3.5, more preferably greater than 4.0.

Preferably, the fragrance or flavour contains at least 10 wt% of fragrance material(s) or flavour material(s) of natural origin based upon the total weight of the fragrance or flavour, preferably at least 30 wt%, more preferably at least 50 wt%, more preferably at least 70 wt%.

Preferably, the fragrance or flavour contains at least 10 wt% of fragrance material(s) or flavour material(s) which have a biodegradation percentage based upon O2 consumption as measured according to ISO-14851 after 28 days of 60 to 100% based upon the total weight of the fragrance or flavour, preferably at least 30 wt%, more preferably at least 50 wt%, more preferably at least 70 wt%.

Preferably, the fragrance or flavour contains at least 80 wt%, preferably at least 90 wt%, more preferably at least 95 wt% of fragrance material(s) or flavour material(s) having at least two Hansen solubility parameters selected from: an atomic dispersion force (5D) from 14 to 20, a dipole moment (5P) of less than 8, and a hydrogen bonding (5H) from 2.5 to 11 , based upon the total weight of the fragrance or flavour.

Preferably, the fragrance or flavour contains only low levels of materials with an alcohol functionality (e.g. a primary alcohol functionality). In preferred methods of the present invention, the fragrance or flavour comprises less than 40 %wt alcohol- containing material based upon the total weight of the fragrance or flavour, more preferably less than 20 %wt. In particularly preferred methods of the present invention, the fragrance or flavour does not comprise an alcohol-containing material. Without wishing to be bound by theory, it is thought that alcohols, and particularly primary alcohols having a straight chain alkyl group, can easily diffuse through the shell of a microcapsule due to their structure, meaning that they can be difficult materials to encapsulate.

Preferably, the fragrance or flavour material is of high odour impact. This is advantageous as it ensures that even low levels of fragrance are perceived when released from the microcapsules.

In preferred methods of the present invention, the plant-based protein solution comprises one or more plant-based protein(s) in a solvent system, wherein the solvent system comprises miscible co-solvents; wherein a first co-solvent increases solubility of the plant-based protein(s), and a second co-solvent decreases solubility of the plantbased protein(s).

The first co-solvent increases solubility of the plant-based protein(s). The first cosolvent may be considered a solubilising co-solvent. There may be one or more solubilising co-solvent(s) and the solubilising co-solvent(s) may fully or partially solubilise the plant-based protein(s).

Examples of solubilising co-solvents are organic acids. An organic acid is an organic compound with acidic properties.

In preferred methods of the present invention, the first co-solvent is an organic acid. Preferably, the organic acid is acetic acid, formic acid, gluconic acid, propionic acid, an a-hydroxy acid, or a p-hydroxy acid. Preferred a-hydroxy acids include glycolic acid, lactic acid, malic acid, citric acid and tartaric acid, preferably lactic acid. Preferred p- hydroxy acids include p-hydroxypropionic acid, p-hydroxybutyric acid, p-hydroxy p- methylbutyric acid, 2-hydroxybenzoic acid and carnitine. In particularly preferred methods of the present invention, the organic acid is lactic acid.

Using an organic acid enables solubilisation of the plant protein and also allows for mild hydrolysis of the protein. For example, without wishing to be bound by theory, the solubility of plant-based proteins in organic acid is possible due to: i) the protonation of proteins and ii) the presence of an anion solvation layer which contributes to a reduction of hydrophobic interactions. Once initially dissolved in organic acid, the protonation of plant-based proteins can help to stabilise them in its non-solvent, for example water.

The second co-solvent has decreased solubility of the plant based protein(s), as compared to the first co-solvent. The second co-solvent may be considered a desolubilising co-solvent. There may be one or more de-solubilising co-solvent(s). In preferred methods of the present invention, the second co-solvent is selected from water, ethanol, and/or ethyl acetate, more preferably water and/or ethanol, even more preferably water.

In preferred methods of the present invention, the solvent system comprises a co-solvent ratio of first co-solvent to second co-solvent of about 10-90% v/v, about 20- 90% v/v, preferably about 20-80% v/v, preferably about 20-60% v/v, about 25-55% v/v, about 30-50% v/v, about 20%, about 30%, about 40% about 50% or about 60% v/v, most preferably about 30-50% v/v.

In preferred methods of the present invention, the concentration of the plantbased protein(s) in the solvent system is 25-200mg/ml, more preferably 50-150mg/ml. The ratio of organic acid may vary depending on protein concentration, e.g. using a higher organic acid ratio with increasing protein concentration.

In preferred methods of the present invention, the degree of protein hydrolysis is controlled to modify the properties of the resultant hydrogel. For example, increasing the acid concentration present during formation will increase the degree of protein hydrolysis. Higher degree of protein hydrolysis leads to the formation of less rigid hydrogels.

In order to form the solution comprising one or more plant-based protein(s), it may be necessary to apply physical stimulus to the protein I solvent system mixture to enable dissolution of the protein. Suitable physical stimulus includes heating, ultrasonication, agitation, high-shear mixing, high-shear homogenisation or other physical techniques. A preferred technique is heating, optionally with subsequent ultrasonication.

Preferably, the protein I solvent system mixture is subjected to a physical stimulus which is heating, wherein the solution is heated to about or above 70°C. More preferably, the protein I solvent system mixture is heated to about or above 75°C, about or above 80°C, about or above 85°C or about 90°C. Even more preferably, the protein I solvent system mixture is heated to 85°C.

Preferably, the protein I solvent system mixture is subjected to a physical stimulus which is heating for a period of about 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, or greater than 30 minutes. The heated protein I solvent system mixture is optionally subjected to subsequent ultrasonication.

The protein solution is then heated such that the liquid solution is held above the sol-gel transition for the protein(s). By modifying the solvent system (for example through selection of the choice of organic acid, the ratio of organic acid to further solvent or through further means) it is possible to modify the sol-gel transition temperature for the protein(s). Through appropriate selection of conditions, it is possible to carefully control the sol-gel transition of the protein thereby controlling the formation of the hydrogel.

Preferably, the protein solution is heated to about or above 70°C. More preferably, the protein is heated to about or above 75°C, about or above 80°C, about or above 85°C or about 90°C. Even more preferably, the protein is heated to 85°C.

The protein solution may be held at elevated temperature for a time period of about 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 45 minutes or 1 hour. A preferred time period is at least 30 minutes to enable the proteins to fully solubilise. It is possible to hold the protein solution at an elevated temperature for a longer period of time.

Without wishing to be bound by theory, it is believed that when the plant protein is added to the solvent system the plant protein forms a highly viscous dispersion of insoluble colloidal protein aggregates. Aggregate size may be measured by Dynamic Light Scattering (DLS). Suitable apparatus to measure aggregate size is a Zetasizer Nano S (Malvern).

It is believed that upon heating the protein solution in the presence of a co-solvent system to above the sol-gel transition temperature, the plant proteins partially unfold, resulting in the exposure of hydrophobic amino acids initially buried within the protein native structure. Once partially unfolded, the co-solvents are able to interact with the unfolded protein molecules. For example, an organic acid has greater access to protonate amino acid residues, as well as enabling the formation of anion salt bridges that stabilise hydrophobic interactions. Also, upon heating at elevated temperatures, protein-protein non-covalent intermolecular contacts are disrupted.

Further, it is believed that the application of mechanical agitation, for example ultrasonication, disrupts large colloidal protein aggregates into smaller ones, as well as disrupting protein intermolecular interactions. Using this approach, the size of the protein aggregates can be significantly reduced, before gelation, to particle sizes below 100nm. Preferably, the method described above comprises protein aggregates with an average size less than 200nm, preferably less than 150nm, less than 125nm, less than 100nm, less than 90nm, less than 80nm, less than 70nm, less than 60nm, less than 50nm, less than 40nm, or less than 30nm. It is therefore thought that at this stage in the method the plant-based protein(s) have secondary structures with high levels of a-helical and random coil. In preferred methods of the present invention, the plant-based protein solution further comprises an additive.

Preferably, said additive is selected from plasticisers, surfactants, rheology modifiers, opacifiers, preservatives, pigments, carbohydrates, gums, polymers, and nanoparticles, or mixtures thereof.

In preferred methods of the present invention, the additive is a plasticiser. Preferably, the additive is selected from glycerol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, propylene glycol, sorbitol, mannitol, xylitol, fatty acids, glucose, mannose, fructose, sucrose, ethanolamine, urea, triethanolamine, vegetable oils, lecithin, waxes and amino acids.

In preferred methods of the present invention, the plant-based protein solution further comprises an amine. The presence of an amine in the plant-based protein solution or the external phase in combination with a polyisocyanate in the lipophilic phase allows for the formation of a polymeric coating on the plant-based protein hydrogel. Preferably, the amine is selected from ethylene diamine, 3,5-diamino-1 ,2,4-triazole, 1 ,3- diaminopropane, diethylene triamine, triethylene tetramine, 1 ,4-diaminobutane, hexamethylene diamine, guanidine or salts thereof, pentaethylene hexamine, diethylenetriamine, bis(3-aminopropyl)amine, and bis(hexamethylene)triamine.

In preferred methods of the present invention, at least 80 wt% of the lipophilic phase, preferably at least 90 wt% of the lipophilic phase, most preferably at least 95 wt% of the lipophilic phase, has at least two Hansen solubility parameters selected from an atomic dispersion force (5D) from 14 to 20, a dipole moment (5P) less than 8, and a hydrogen bonding (5H) from 2.5 to 11 .

In preferred methods of the present invention, the lipophilic phase further comprises an oil-miscible solvent.

Preferably, the oil-miscible solvent is a solvent with low volatility (e.g. having a vapour pressure of less than 0.1 Torr at 25°C, preferably less than 0.01 Torr at 25°C, preferably less than 0.001 Torr at 25°C).

Preferably the oil-miscible solvent has low or no odour.

Preferably, the oil-miscible solvent has at least two Hansen solubility parameters selected from: an atomic dispersion force (5D) of less than 20, a dipole moment (5P) of less than 8, and a hydrogen bonding (5H) of less than 11. More preferably, the oil- miscible solvent has at least two Hansen solubility parameters selected from: an atomic dispersion force (5D) of less than 20, a dipole moment (5P) of less than 4, and a hydrogen bonding (5H) of less than 5. Preferably, the oil-miscible solvent has a density of greater than 1.07g/cm ³ . Oil- miscible solvents having this property are advantageously able to prevent creaming of the encapsulates (e.g. in a final product formulation).

Preferably, the oil-miscible solvent contains only low levels of materials with an alcohol functionality (e.g. a primary alcohol functionality). In preferred methods of the present invention, the oil-miscible solvent comprises less than 40 %wt alcohol-containing material based upon the total weight of the oil-miscible solvent, more preferably less than 20 %wt. In particularly preferred methods of the present invention, the oil-miscible solvent does not comprise an alcohol-containing material.

In preferred methods of the present invention, the oil-miscible solvent in the lipophilic phase is selected from a carboxylic acid ester, a fatty acid ester, a phthalate ester, a triol, a diol, a rosin resin, an isoparaffin, a terpene, and a vegetable oil, or combinations thereof.

Preferably, the oil-miscible solvent in the lipophilic phase is selected from Miglyol® 840, Miglyol® 812 N, Miglyol® 829, Miglyol® 829 ECO, Miglyol® Coco 810, Miglyol® 810 N, Miglyol® 128, Miglyol® 808 Miglyol® T-C7, Miglyol® 8810, Miglyol® PPG 810, Miglyol® OE, Miglyol® DO, and Miglyol® 818, Abalyn®, limonene, benzyl benzoate, diethyl phthalate, isopropyl myristate, triethyl citrate, dipropylene glycol, propylene glycol, triacetin, glycerin, and 1 ,3 propanediol, or combinations thereof, preferably Miglyol® 812 N. Preferably, the lipophilic phase comprises a material that functions as a viscosity modifier (e.g. Abalyn®).

Preferably, the oil-miscible solvent in the lipophilic phase is a vegetable oil selected from coconut oil, corn oil, canola oil, cottonseed oil, olive oil, palm oil, peanut oil, rapeseed oil, safflower oil, sesame oil, soybean oil, and sunflower oil. Other examples of vegetable oils are given in the CTFA Cosmetic Ingredient Handbook, J.M. Nikitakis (ed.), 1st ed., The Cosmetic, Toiletry and Fragrance Association, Inc., Washington, 1988. A vegetable oil is an oil that comes from plant sources. Alternatively, the solvent is derived from a vegetable oil.

In preferred methods of the present invention, the lipophilic phase comprises 0 to 80% oil-miscible solvent by volume, preferably 0 to 60%, more preferably 0 to 50%, more preferably 0 to 40%, more preferably 0 to 20%.

In preferred methods of the present invention, the lipophilic phase further comprises a silicon-containing compound. The presence of a silicon-containing compound in the lipophilic phase allows for the formation of a silicon-based coating on the internal surface of the plant-based protein hydrogel (i.e. at the oil droplet interface). Preferably, the silicon-containing compound is selected from tetraethyl orthosilicate, tetrapropyl orthosilicate, dimethyl diethoxysilane and tetramethyl orthosilicate or combinations thereof, preferably tetraethyl orthosilicate.

In preferred methods of the present invention, the lipophilic phase further comprises a polyisocyanate. The presence of a polyisocyanate in the lipophilic phase allows for the formation of a polymeric coating on the plant-based protein hydrogel via reaction between the isocyanate groups and the amine groups present in the protein. Additionally, the presence of a polyisocyanate in the lipophilic phase in combination with an amine in the plant-based protein solution or the external phase allows for the formation of a polymeric coating on the plant-based protein hydrogel via reaction between the isocyanate groups and the amine groups of the added amine. Preferably the polyisocyanate is selected from a trimethylol propane adduct of xylylene diisocyanate (Takenate® D-110N), polyisocyanurate of toluene diisocyanate (Desmodur® RC), or hexamethylele diisocyanate biuret (Desmodur N 100).

In preferred methods of the present invention, the lipophilic phase further comprises a surfactant, preferably an anionic surfactant.

In preferred methods of the present invention, in step (a) the lipophilic phase is cooled to a temperature of less than 20 °C prior to emulsification.

In preferred methods of the present invention, step (a) is conducted at atmospheric pressure. For example, step (a) is a bulk emulsification process (e.g. involving low or high shear mechanical stirring). Thus, in step (a) the primary emulsion is preferably held at a temperature above the sol-gel transition temperature of the plantbased protein(s) for a time period of less than 15 minutes, preferably less than 10 minutes, more preferably less than 5 minutes.

In alternative methods of the present invention, step (a) is conducted at elevated pressure (e.g. in a closed system). For example, step (a) is a membrane emulsification process. Preferably, the membrane emulsification process involves the use of a membrane having a pore size of 3 to 350 pm, preferably 3.5 to 250 pm, more preferably

4 to 150 pm, more preferably 4.5 to 75 pm, more preferably 5 to 50 pm, more preferably

5 to 20 pm, more preferably 5 to 15 pm.

Accordingly, the primary emulsion preferably has a diameter of 3 to 350 pm, preferably 3.5 to 250 pm, more preferably 4 to 150 pm, more preferably 4.5 to 75 pm, more preferably 5 to 50 pm, more preferably 5 to 20 pm, more preferably 5 to 15 pm, as measured by optical microscopy. In preferred methods of the present invention, the weight ratio of the lipophilic phase to plant-based protein(s) solids in step (a) is in the range 1 :5 to 350:1 , preferably 1 :3 to 60:1 , more preferably 1 :1 to 40:1 , most preferably 2:1 to 25:1.

In preferred methods of the present invention, the external phase comprises a solvent and/or a polymer.

Preferably, the external phase comprises a solvent. More preferably, the solvent is selected from a fatty acid ester, a vegetable oil, a hydrocarbon oil, and silicone oil (i.e. polydimethylsiloxane).

Preferred fatty acid esters are selected from Miglyol® 840, Miglyol® 812 N, Miglyol® 829, Miglyol® 829 ECO, Miglyol® Coco 810, Miglyol® 810 N, Miglyol® 128, Miglyol® 808, Miglyol® T-C7, Miglyol® 8810, Miglyol® PPG 810, Miglyol® OE, Miglyol® DO, and Miglyol® 818, or combinations thereof, preferably Miglyol® 840.

Preferred vegetable oils are selected from coconut oil, corn oil, canola oil, cottonseed oil, olive oil, palm oil, peanut oil, rapeseed oil, safflower oil, sesame oil, soybean oil, and sunflower oil. Other examples of vegetable oils are given in the CTFA Cosmetic Ingredient Handbook, J.M. Nikitakis (ed.), 1st ed., The Cosmetic, Toiletry and Fragrance Association, Inc., Washington, 1988. Alternatively, the solvent is derived from a vegetable oil.

Preferred hydrocarbon oils are paraffin oils.

Preferably, the external phase comprises a polymer. More preferably, the polymer is selected from dextran, pullulan, polyethylene glycol, and polyvinyl alcohol, or combinations thereof, preferably dextran and/or pullulan.

In preferred methods of the present invention, the external phase further comprises a surfactant. Preferably, the surfactant in the external phase is selected from sucrose fatty acid esters such as sucrose stearic acid ester, sucrose palmitic acid ester, sucrose oleic acid ester, sucrose lauric acid ester, sucrose behenic acid ester, and sucrose erucic acid ester; sorbitan fatty acid esters such as sorbitan monostearate, sorbitan tristearate, sorbitan monooleate, sorbitan trioleate, and sorbitan sesquioleate; glyceryl fatty acid esters such as glycerol monostearate and glycerol monooleate; and polyglyceryl fatty acid esters such as diglyceryl tetraisostearate, diglyceryl diisostearate, diglyceryl monoisostearate, and polyglycerol polyricinoleate, preferably polyglycerol polyricinoleate.

In preferred methods of the present invention, the external phase further comprises a silicon-containing compound. The presence of a silicon-containing compound in the external phase allows for the formation of an external silicon-based coating on the plant-based protein hydrogel. Preferably, the silicon-containing compound is selected from tetraethyl orthosilicate, tetrapropyl orthosilicate, dimethyl diethoxysilane and tetramethyl orthosilicate or combinations thereof, preferably tetraethyl orthosilicate.

In preferred methods of the present invention, the external phase further comprises an amine. The presence of an amine in the plant-based protein solution or the external phase in combination with a polyisocyanate in the lipophilic phase allows for the formation of a polymeric coating on the plant-based protein hydrogel via reaction between the isocyanate groups and the amine groups. Preferably, the amine is selected from ethylene diamine, 3,5-diamino-1 ,2,4-triazole, 1 ,3-diaminopropane, diethylene triamine, triethylene tetramine, 1 ,4-diaminobutane, hexamethylene diamine, guanidine or salts thereof, pentaethylene hexamine, diethylenetriamine, bis(3-aminopropyl)amine, and bis(hexamethylene)triamine.

In preferred methods of the present invention, step (b) is conducted at atmospheric pressure. For example, step (b) is a bulk emulsification process (e.g. involving low or high shear mechanical stirring).

In preferred methods of the present invention, step (b) is performed immediately after step (a).

In preferred methods of the present invention, in step (b) the external phase is at a temperature that is at least 5 °C higher than the sol-gel transition temperature of the plant-based protein(s), preferably at least 4 °C higher, preferably at least 3 °C higher, preferably at least 2 °C higher, preferably at least 1 °C higher.

In preferred methods of the present invention, the weight ratio of the external phase to the primary emulsion in step (b) is greater than 1 :1 , more preferably greater than 2:1 , more preferably greater than 3:1.

In preferred methods of the present invention, the storage modulus (G’) at 10 rad/s of the plant-based protein hydrogel formed in step (c) is greater than 500 Pa, preferably greater than 1000 Pa, preferably greater than 2500 Pa, preferably greater than 3000 Pa, preferably greater than 4000 Pa.

In preferred methods of the present invention, in step (c) the secondary emulsion is reduced to a temperature below the sol-gel transition temperature of the plant-based protein(s) to form the plant-based protein hydrogel.

Preferably, in step (c) the secondary emulsion is reduced to a temperature of less than 20°C, preferably less than 10°C, preferably less than 5°C. The secondary emulsion may be held at the reduced temperature for a time period of about 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes or about 30 minutes. Without wishing to be bound by theory it is believed that upon cooling the secondary emulsion to below the sol-gel transition temperature, protein-protein non- covalent intermolecular contacts are enabled, thus promoting the self-assembly of plant protein molecules into a network of supramolecular aggregates.

After gelation, the aggregates may be fine stranded. The aggregates may have a median average length of between 50 to 500nm. The aggregates may have a mean average length of between 50 to 500nm. 80% of the aggregates may have an average length of between 50 to 500nm. The aggregates may have a median height of between 5 to 50nm. The aggregates may have a mean average height of between 5 to 50nm. 80% of the aggregates may have an average height of between 5 to 50nm. In a preferred embodiment, the aggregates have a median average length of between 50 to 500nm and/or a median average height of between 5 to 50nm.

Without wishing to be bound by theory, it is thought that the method described above allows the plant proteins to aggregate into supramolecular structures held by intermolecular hydrogen bonding interactions, and in particular between the p-strands. Thus, preferably, the plant-based protein hydrogel has high levels of p-sheet intermolecular interactions.

In preferred methods of the present invention, the method does not involve a microfluidic process.

In preferred methods of the present invention, in step (d) the external phase is separated from the microcapsule by decantation, gravity separation, filtration, froth filtration, centrifugation or drying.

In preferred methods of the present invention, in step (d) the external phase is separated from the microcapsule by decantation, gravity separation, filtration, froth filtration, centrifugation or drying prior to washing the microcapsule with water, preferably hard water.

Preferred methods of the present invention further comprise sieving the microcapsule.

The methods of the present invention further comprise subjecting the microcapsule to one or more post-treatment steps. Each post-treatment step can advantageously improve the physical and chemical stability of the microcapsules. In particular, aech post-treatment step can improve the leakage/diffusion stability of the microcapsules such that they are better able to retain the fragrance material(s) or flavour material(s). In accordance with the present invention, the post-treatment step comprises a coating formation step.

In particular, the coating formation step comprises treating the microcapsule with a silicon-containing compound to form a silicon-based coating. Preferably, said silicon- containing compound is selected from sodium silicate, tetraethyl orthosilicate, tetrapropyl orthosilicate, dimethyl diethoxysilane and tetramethyl orthosilicate, or combinations thereof, more preferably wherein the sodium silicate is selected from sodium metasilicate, sodium orthosilicate and sodium pyrosilicate, with sodium metasilicate being most preferred. As will be understood by a skilled person, depending in which phase the silicon compound is present, the silicon-based coating can be formed on either the internal surface of the plant-based protein hydrogel (i.e. at the oil droplet interface) or the external surface of the plant-based protein hydrogel (i.e. to form a shell around the microcapsule).

As will be understood by a skilled person, it is possible for multiple post-treatment steps to be performed. For example, the microcapsule is subjected to an electrostatic I non-covalent cross-linking step using sodium tripolyphosphate (NaTPP) followed by a silica coating using poly-L-lysine as deposition aid. In a preferred method of the present invention, the microcapsule is subjected to a non-covalent cross-linking step using tannic acid followed by a coacervate coating formation step using xanthan gum.

In preferred methods of the present invention, a post-treatment step comprises a non-covalent cross-linking step. Preferably, the non-covalent cross-linking step comprises treating the microcapsule with a non-covalent cross linker selected from sodium tripolyphosphate (NaTPP), sodium hexametaphosphate, and phenolic compounds (e.g. tannic acid, caffeic acid etc., with tannic acid being most preferred).

In preferred methods of the present invention, a post-treatment step comprises a covalent cross-linking step. Preferably, the covalent cross-linking step comprises treating the microcapsule with a covalent cross linker selected from genipin, epoxy compounds, glyceraldehyde, glutaraldehyde, formaldehyde, glyoxal, dialdehyde starch, microbial transglutaminase, and PolyCup® crosslinking resin, or combinations thereof.

In preferred methods of the present invention, a post-treatment step comprises a coating formation step.

Preferably, the coating formation step comprises treating the microcapsule with a metal compound to form a metal coating. More preferably, the metal compound is selected from a silver compound or a gold compound, preferably a silver compound. In preferred methods of the present invention, the coating formation step comprises subjecting the microcapsule to a complex coacervation step using a polysaccharide to form a coacervate coating. Preferably, the polysaccharide is selected from xanthan gum, gellan gum, and chitosan or combinations thereof, with xanthan gum being most preferred.

In preferred methods of the present invention, the coating formation step comprises treating the microcapsule with an aqueous mineral solution to form a mineral coating. Preferably, the aqueous mineral solution comprises iron salts, calcium salts, phosphate salts, carbonate salts, titanium salts or zinc salts, or combinations thereof.

In preferred methods of the present invention, the coating formation step comprises treating the microcapsule with a polyisocyanate to form a polymeric coating. As outlined above, this can be achieved by the polyisocyanate being present in the lipophilic phase during earlier steps in the method. Preferred polyisocyanates are described above.

In preferred methods of the present invention, the coating formation step comprises treating the microcapsule with a polyisocyanate and an amine to form a polymeric coating. As outlined above, this can be achieved by the polyisocyanate being present in the lipophilic phase and the amine being present in either the plant-based protein solution or the external phase during earlier steps in the method. Preferred polyisocyanates and amines are described above. As will be understood by a skilled person, depending in which phases the polyisocyanate and the amine are present, the polymeric coating can be formed on either the internal surface of the plant-based protein hydrogel (i.e. at the oil droplet interface) or the external surface of the plant-based protein hydrogel (i.e. to form a shell around the microcapsule).

Preferred methods of the present invention further comprise drying the microcapsule. The drying may be performed before, after or sequentially with step (d). Preferably, the drying is performed after step (d).

Preferably, the drying is selected from spray drying, fluid bed drying and/or tray drying.

Preferred methods of the present invention further comprise re-suspending the microcapsule in an external phase, preferably an external aqueous phase, preferably hard water or an acidic buffer solution.

The present invention also provides a biodegradable microcapsule obtained by or obtainable by the method as hereinbefore described. The present invention also provides a method for preparing a biodegradable microcapsule composition, comprising:

(a) emulsifying a lipophilic phase comprising a fragrance or a mixture of fragrances in a plant-based protein solution comprising one or more plant-based protein(s), wherein said lipophilic phase is immiscible with said plant-based protein solution, to give a primary emulsion;

(b) re-emulsifying said primary emulsion in an external phase to give a secondary emulsion, wherein said external phase is immiscible with said primary emulsion; and

(c) inducing the plant-based protein(s) to undergo a sol-gel transition to from a plantbased protein hydrogel, wherein said plant-based protein hydrogel encapsulates said lipophilic phase to form a biodegradable microcapsule which is suspended in said external phase; wherein said plant-based protein solution is at a temperature above the sol-gel transition temperature of the plant-based protein(s) during steps (a) and (b).

Preferred features of each of steps (a), (b) and (c) are as described above.

Preferred methods of the present invention further comprise:

(d) removing at least part of the external phase from the microcapsule; and

(e) re-suspending the microcapsule in an external phase.

Preferably, the external phase is an external aqueous phase, more preferably hard water or an acidic buffer solution.

Preferred methods of the present invention further comprise adding a suspending agent(s) to said external phase. Preferably, said suspending agent(s) is selected from acacia gum, alginic acid, pectin, xanthan gum, gellan gum, carbomer, dextrin, gelatin, guar gum, hydrogenated vegetable oil category 1 , aluminum magnesium silicate, maltodextrin, carboxymethyl cellulose, polymethacrylate, poly vinyl pyrrolidone, sodium alginate, starch, zein, water-insoluble cross-linked polymers such as cross-linked cellulose, cross-linked starch, cross-linked CMC, cross-linked carboxymethyl starch, cross-linked polyacrylate, and cross-linked polyvinylpyrrolidone, and expanded clays such as bentonite and laponite.

The present invention also provides a biodegradable microcapsule composition obtained by or obtainable by the method as hereinbefore described.

The present invention also provides biodegradable microcapsule comprising:

(a) a lipophilic phase comprising at least one fragrance material or flavour material; and

(b) a plant-based protein hydrogel comprising at least one plant-based protein(s); wherein: said plant-based protein hydrogel encapsulates said lipophilic phase; said plant-based protein hydrogel has a silicon-containing coating deposited thereon; and the biodegradation percentage based upon O2 consumption of the plant-based protein hydrogel as measured according to ISO-14851 after 28 days is 60 to 100%.

The microcapsules of the present invention are able to effectively encapsulate fragrance materials and/or flavour materials having a range of volatilities, allowing for complex fragrance and flavour profiles to be achieved upon breakage of the microcapsules. The microcapsules comprise a plant-based protein hydrogel, which encapsulates a lipophilic phase comprising at least one fragrance material or flavour material. The plant-based protein hydrogel has a silicon-containing coating deposited thereon. This reinforcement of the plant-based protein hydrogel means that the fragrance materials and/or flavour materials have a superior retention in the microcapsule. This allows the microcapsules to be particularly useful in a final consumer product.

In preferred biodegradable microcapsules of the present invention, said silicon- based coating is formed from a silicon-containing compound. Preferably, said silicon- containing compound is selected from sodium metasilicate, tetraethyl orthosilicate, tetrapropyl orthosilicate, dimethyl diethoxysilane and tetramethyl orthosilicate, or combinations thereof, preferably sodium metasilicate.

The microcapsules of the present invention achieve the biodegradability requirements under fresh water conditions for microplastics, as stipulated by ISO-14851. Accordingly, the microcapsules of the present invention represent environmentally- friendly encapsulation technology, which is particularly suited to use in home care and personal care applications, as if the microcapsules ultimately end up in waterways/the sea they will fully biodegrade in a short amount of time.

In preferred biodegradable microcapsules of the present invention, the biodegradation percentage based upon O2 consumption of the plant-based protein hydrogel as measured according to ISO-14851 after 28 days is 65 to 100%, more preferably 80 to 100%, more preferably 85 to 100%, even more preferably 90 to 100%.

In preferred biodegradable microcapsules of the present invention, the plantbased protein(s) is obtained from fava bean, mung bean, pea, rice, potato, rapeseed, lentil, chickpea, sunflower seed, pumpkin seed, flax, chia, canola, lupine, alfalfa, moringa, wheat, corn zein or sorghum; preferably the plant protein(s) is selected from pea protein, potato protein, rapeseed protein, lentil protein, chickpea protein, fava bean protein, mung bean protein, sunflower seed protein, pumpkin seed protein, flax protein, chia protein, canola protein, lupine protein, alfalfa protein, moringa protein and/or rice protein, more preferably pea protein and/or potato protein. Such proteins are considered to be low allergenicity proteins.

In preferred biodegradable microcapsules of the present invention, the plantbased protein(s) has been pre-treated with an organic acid. Preferably, the organic acid is acetic acid, formic acid, propionic acid, gluconic acid, an a-hydroxy acid, or a p-hydroxy acid. Particularly preferably, the organic acid is lactic acid.

Preferred a-hydroxy acids include glycolic acid, lactic acid, malic acid, citric acid and tartaric acid, preferably lactic acid. Preferred p-hydroxy acids include p- hydroxypropionic acid, p-hydroxybutyric acid, p-hydroxy p-methylbutyric acid, 2- hydroxybenzoic acid and carnitine.

In preferred biodegradable microcapsules of the present invention, the at least one fragrance material or flavour material is selected from an alcohol, an aldehyde, a ketone, an ester, an ether, an acetate, an alkene, a nitrile, a nitrogenous heterocyclic compound, a sulfurous heterocyclic compound, and a Schiff base. Suitable fragrance materials and flavour materials are described above.

In preferred biodegradable microcapsules of the present invention, the at least one fragrance material or flavour material has a vapour pressure of greater than or equal to 0.0001 Torr at 25°C, preferably greater than or equal to 0.001 Torr at 25°C

In preferred biodegradable microcapsules of the present invention, the at least one fragrance material or flavour material has a logP greater than or equal to 3.0.

In preferred biodegradable microcapsules of the present invention, the at least one fragrance material or flavour material has at least two Hansen solubility parameters selected from: an atomic dispersion force (5D) from 14 to 20, a dipole moment (5P) of less than 8, and a hydrogen bonding (5H) from 2.5 to 11 .

In preferred biodegradable microcapsules of the present invention, the at least one fragrance material or flavour material is part of a fragrance or flavour.

Preferably, the fragrance or flavour contains at least 20 wt% of fragrance material(s) or flavour material(s) with a vapour pressure greater than or equal to 0.001 Torr at 25°C based upon the total weight of the fragrance or flavour, more preferably 40 wt%, more preferably 60 wt%.

Preferably, the fragrance or flavour contains at least 20 wt% of fragrance material(s) or flavour material(s) with a logP greater than 3.0 based upon the total weight of the fragrance or flavour, more preferably greater than 3.5, more preferably greater than 4.0. Preferably, the fragrance or flavour contains at least 40 wt% of fragrance material(s) or flavour material(s) with a logP greater than 3.0 based upon the total weight of the fragrance or flavour, more preferably greater than 3.5, more preferably greater than 4.0.

Preferably, the fragrance or flavour contains at least 50 wt% of fragrance material(s) or flavour material(s) with a logP greater than 3.0 based upon the total weight of the fragrance or flavour, more preferably greater than 3.5, more preferably greater than 4.0.

Preferably, the fragrance or flavour contains at least 60 wt% of fragrance material(s) or flavour material(s) with a logP greater than 3.0 based upon the total weight of the fragrance or flavour, more preferably greater than 3.5, more preferably greater than 4.0.

Preferably, the fragrance or flavour contains at least 10 wt% of fragrance material(s) or flavour material(s) of natural origin based upon the total weight of the fragrance or flavour, preferably at least 20 wt%, more preferably at least 50 wt%, more preferably at least 70 wt%.

Preferably, the fragrance or flavour contains at least 10 wt% of fragrance material(s) or flavour material(s) which have a biodegradation percentage based upon O2 consumption as measured according to ISO-14851 after 28 days of 60 to 100% based upon the total weight of the fragrance or flavour, preferably at least 30 wt%, more preferably at least 50 wt%, more preferably at least 70 wt%.

Preferably, the fragrance or flavour contains at least 80 wt%, preferably at least 90 wt%, more preferably at least 95 wt% of fragrance material(s) or flavour material(s) having at least two Hansen solubility parameters selected from: an atomic dispersion force (5D) from 14 to 20, a dipole moment (5P) of less than 8, and a hydrogen bonding (5H) from 2.5 to 11 , based upon the total weight of the fragrance or flavour.

Preferably, the fragrance or flavour contains only low levels of materials with an alcohol functionality (e.g. a primary alcohol functionality. In preferred biodegradable microcapsules of the present invention, the fragrance or flavour comprises less than 40 %wt alcohol-containing material based upon the total weight of the fragrance or flavour, more preferably less than 20 %wt. In particularly preferred biodegradable microcapsules of the present invention, the fragrance or flavour does not comprise an alcohol-containing material. Preferably, the fragrance or flavour material is of high odour impact. This is advantageous as it ensures that even low levels of fragrance are perceived when released from the microcapsules.

In preferred biodegradable microcapsules of the present invention, at least 80 wt% of the lipophilic phase, preferably at least 90 wt% of the lipophilic phase, most preferably at least 95 wt% of the lipophilic phase, has at least two Hansen solubility parameters selected from an atomic dispersion force (5D) from 14 to 20, a dipole moment (5P) less than 8, and a hydrogen bonding (5H) from 2.5 to 11 .

In preferred biodegradable microcapsules of the present invention, said lipophilic phase further comprises an oil-miscible solvent.

Preferably, the oil-miscible solvent is a solvent with low volatility (e.g. having a vapour pressure of less than 0.1 Torr at 25°C, preferably less than 0.01 Torr at 25°C, preferably less than 0.001 Torr at 25°C).

Preferably the oil-miscible solvent has low or no odour.

Preferably, the oil-miscible solvent has at least two Hansen solubility parameters selected from: an atomic dispersion force (5D) of less than 20, a dipole moment (5P) of less than 8, and a hydrogen bonding (5H) of less than 11. More preferably, the oil- miscible solvent has at least two Hansen solubility parameters selected from: an atomic dispersion force (5D) of less than 20, a dipole moment (5P) of less than 4, and a hydrogen bonding (5H) of less than 5.

Preferably, the oil-miscible solvent has a density of greater than 1 ,07g/cm ³ . Oil- miscible solvents having this property are advantageously able to prevent creaming of the encapsulates (e.g. in a final product formulation).

Preferably, the oil-miscible solvent contains only low levels of materials with an alcohol functionality (e.g. a primary alcohol functionality). In preferred biodegradable microcapsules of the present invention, the oil-miscible solvent comprises less than 40 %wt alcohol-containing material based upon the total weight of the oil-miscible solvent, more preferably less than 20 %wt. In particularly preferred biodegradable microcapsules of the present invention, the oil-miscible solvent does not comprise an alcohol-containing material.

In preferred biodegradable microcapsules of the present invention, the oil- miscible solvent in the lipophilic phase is selected from a carboxylic acid ester, a fatty acid ester, a phthalate ester, a triol, a diol, a rosin resin, an isoparaffin, a terpene, and a vegetable oil, or combinations thereof. Preferably, the oil-miscible solvent in the lipophilic phase is selected from Miglyol® 840, Miglyol® 812 N, Miglyol® 829, Miglyol® 829 ECO, Miglyol® Coco 810, Miglyol® 810 N, Miglyol® 128, Miglyol® 808, Miglyol® T-C7, Miglyol® 8810, Miglyol® PPG 810 Miglyol® OE, Miglyol® DO, Miglyol® 818, Abalyn®, limonene, benzyl benzoate, diethyl phthalate, isopropyl myristate, triethyl citrate, dipropylene glycol, and propylene glycol, or combinations thereof, preferably Miglyol® 812 N.

Preferably, the oil-miscible solvent in the lipophilic phase is a vegetable oil selected from coconut oil, corn oil, canola oil, cottonseed oil, olive oil, palm oil, peanut oil, rapeseed oil, safflower oil, sesame oil, soybean oil, and sunflower oil. Other examples of vegetable oils are given in the CTFA Cosmetic Ingredient Handbook, J.M. Nikitakis (ed.), 1st ed., The Cosmetic, Toiletry and Fragrance Association, Inc., Washington, 1988. Alternatively, the solvent is derived from a vegetable oil.

In preferred biodegradable microcapsules of the present invention, the lipophilic phase comprises 0 to 80% oil-miscible solvent by volume, preferably 0 to 60%, more preferably 0 to 50%, more preferably 0 to 40%, more preferably 0 to 20%.

In preferred biodegradable microcapsules of the present invention, said lipophilic phase further comprises a surfactant, preferably an anionic surfactant.

In preferred biodegradable microcapsules of the present invention, said plantbased protein hydrogel has been non-covalently modified by a non-covalent cross-linker selected from sodium tripolyphosphate, sodium hexametaphosphate, and phenolic compounds (e.g. tannic acid, caffeic acid etc., with tannic acid being most preferred).

In preferred biodegradable microcapsules of the present invention, said plantbased protein hydrogel has been covalently modified by a covalent cross-linker selected from genipin, epoxy compounds, glyceraldehyde, glutaraldehyde, formaldehyde, glyoxal, dialdehyde starch, microbial transglutaminase, and PolyCup® crosslinking resin, or combinations thereof.

In preferred biodegradable microcapsules of the present invention, said coating is a metal coating, a polymeric coating, a coacervate coating, or a mineral coating.

In preferred biodegradable microcapsules of the present invention, said coating is a metal coating which is a silver coating or a gold coating, preferably a silver coating.

In preferred biodegradable microcapsules of the present invention, said coating is a coacervate coating which is formed from a polysaccharide. Preferably, said polysaccharide is selected from xanthan gum, gellan gum, and chitosan, or combinations thereof, with xanthan gum being most preferred. In preferred biodegradable microcapsules of the present invention, said coating is a mineral coating which is formed from an aqueous mineral solution. Preferably, the aqueous mineral solution comprises iron salts, calcium salts, phosphate salts, carbonate salts, titanium salts or zinc salts, or combinations thereof.

In preferred biodegradable microcapsules of the present invention, said coating is a polymeric coating which is formed from shellac, a polyisocyanate, or a polyisocyanate and an amine.

Preferably, said polyisocyanate is selected from a trimethylol propane adduct of xylylene diisocyanate (Takenate® D-110N), polyisocyanurate of toluene diisocyanate (Desmodur® RC), or hexamethylele diisocyanate biuret (Desmodur N 100).

Preferably, said amine is selected from selected from ethylene diamine, 3,5- diamino-1 ,2,4-triazole, 1 ,3-diaminopropane, diethylene triamine, triethylene tetramine, 1 ,4-diaminobutane, hexamethylene diamine, guanidine or salts thereof, pentaethylene hexamine, diethylenetriamine, bis(3-aminopropyl)amine, and bis(hexamethylene)triamine.

Preferred biodegradable microcapsules of the present invention have a coating deposited on the covalently-modified or non-covalently modified plant-based protein hydrogel. Preferred features of the coatings are as described above.

Preferred biodegradable microcapsules of the present invention are core-shell microcapsules.

Preferably, the core-shell microcapsule has a multicore morphology. Alternatively, the core-shell microcapsule has a single core morphology.

Preferred biodegradable microcapsules of the present invention are matrix microcapsules.

Preferred biodegradable microcapsules of the present invention have a diameter of less than or equal to 250 pm, less than or equal to 200 pm, less than or equal to 150 pm, less than or equal to 100 pm, less than or equal to 50 pm, as measured by optical microscopy.

In preferred biodegradable microcapsules of the present invention, said plantbased protein hydrogel comprises plant-based proteins having a protein secondary structure with at least 40% intermolecular p-sheet, at least 50% intermolecular p-sheet, at least 60% intermolecular p-sheet, at least 70% intermolecular p-sheet, at least 80% intermolecular p-sheet, or at least 90% intermolecular p-sheet, wherein the % intermolecular p-sheet content is measured by FTIR (Fourier transform infrared spectroscopy). In preferred biodegradable microcapsules of the present invention, the at least one fragrance material or flavour material is part of a fragrance or flavour and the microcapsule comprises on a dry basis a weight ratio of fragrance or flavour to plantbased protein(s) in the range 1 :5 to 300:1 , preferably 1 :3 to 50:1 , more preferably 1 :1 to 25: 1 , most preferably 2: 1 to 20: 1.

In preferred biodegradable microcapsules of the present invention, the at least one fragrance material or flavour material is part of a fragrance or flavour and at least 50%, more preferably at least 70%, even more preferably at least 80%, even more preferably at least 90% of the total fragrance or flavour encapsulated is present inside the microcapsule after incubation in hard water at 37 °C for 72 hours, as determined by GC.

In preferred biodegradable microcapsules of the present invention, the at least one fragrance material or flavour material is part of a fragrance or flavour and at least 50%, more preferably at least 70%, even more preferably at least 80%, even more preferably at least 90% of the fragrance or flavour initially encapsulated remains present inside the microcapsule after incubation in hard water at 37 °C for 72 hours, as determined by GC.

In preferred biodegradable microcapsules of the present invention, the at least one fragrance material or flavour material is part of a fragrance or flavour and at least 25%, more preferably at least 30%, more preferably at least 35%, more preferably at least 40%, even more preferably at least 50%, even more preferably at least 60% of the total fragrance or flavour encapsulated is present inside the microcapsule after incubation in a standard fabric conditioner formulation at 37 °C for 24 hours, as determined by GC.

In preferred biodegradable microcapsules of the present invention, the at least one fragrance material or flavour material is part of a fragrance or flavour and wherein at least 25%, preferably at least 30%, more preferably at least 35%, more preferably at least 40%, even more preferably at least 50%, even more preferably at least 60% of the fragrance or flavour initially encapsulated remains present inside the microcapsule after incubation in a standard fabric conditioner formulation at 37 °C for 24 hours, as determined by GC.

In preferred biodegradable microcapsules of the present invention, the microcapsule releases the at least one fragrance material or flavour material when applied and dried onto a surface and upon application of a force to the microcapsule. Such action can result in a sudden and noticeable fragrance or flavour bloom. Preferably, the surface is a bio-surface, glass, paper, card or a textile. Examples of a bio-surface include hair, skin and teeth. Force may be applied directly by touching, rubbing or squeezing or via a device such as brush, comb or mop. Oil being released can be seen visually under a light microscope and the result can also be assessed olfactively.

The rupture-force value (also known as the bursting-force value) of individual microcapsules are measured via a computer-controlled micromanipulation instrument system which possesses lenses and cameras able to image the microcapsules, and which possesses a fine, flat-ended probe connected to a force-transducer (such as the Model 403A available from Aurora Scientific Inc, Canada, or equivalent), as described in: Zhang, Z. et al. (1999), J. Microencapsulation, vol 16, no. 1 , pages 117-124, and in: Sun, G. and Zhang, Z. (2001), J. Microencapsulation, vol 18, no. 5, pages 593-602.

In preferred biodegradable microcapsules of the present invention, the microcapsule releases the at least one fragrance material or flavour material as a result of enzymatic degradation of the plant-based protein hydrogel. Preferably, said enzymatic degradation is triggered by enzymes on the skin or in the oral cavity of a human or animal, or by enzymes present in a consumer product (e.g. a cleaning product).

The present invention also provides a composition comprising a biodegradable microcapsule as hereinbefore described and an external phase. The external phase optionally includes a non-encapsulated fragrance material(s) or flavour material(s) that may be the same or different from the encapsulated fragrance material(s) or flavour material(s). The external phase optionally includes other fragrance and flavour delivery systems such as non-biodegradable encapsulates, cyclodextrins or polymer-assisted delivery.

The present invention also provides a consumer product comprising a biodegradable microcapsule as hereinbefore described. Preferably, the consumer product is a fabric conditioner, liquid scent booster, solid scent booster, liquid detergent, powdered detergent, bar soap, shower gel, hair conditioner, shampoo, hair dye or colourant, dishwashing liquid, hard surface cleaner, toilet block, coated fabric, coated paper, wipe, deodorant, antiperspirant, room deodoriser, cosmetic formulation, fine fragrance, perfume additive bead, foodstuff, beverage, toothpaste, mouthwash, chewing gum, nutraceutical product, or pharmaceutical product.

The present invention also provides a method of making a consumer product, comprising:

(a) preparing a biodegradable microcapsule according to the method hereinbefore described; and (b) mixing said biodegradable microcapsule with a consumer product formulation.

In preferred methods of the present invention, the consumer product is a fabric conditioner, liquid scent booster, solid scent booster, liquid detergent, powdered detergent, bar soap, shower gel, hair conditioner, shampoo, hair dye or colourant, dishwashing liquid, hard surface cleaner, toilet block, coated fabric, coated paper, wipe, deodorant, antiperspirant, room deodoriser, cosmetic formulation, fine fragrance, perfume additive bead, foodstuff, beverage, toothpaste, mouthwash, chewing gum, nutraceutical product, or pharmaceutical product.

In preferred methods of the present invention, the consumer product formulation has a viscosity of less than 100 mPa.s at 2(TC and 50 s ^-1 .

In alternative preferred methods of the present invention, the consumer product formulation has a viscosity of more than 500 mPa.s at 20°C and 50 s ^-1 , preferably more than 1000 mPa.s at 20°C and 50 s ^-1 .

The present invention also provides the use of a biodegradable microcapsule as hereinbefore described in a consumer product. Preferably, the consumer product is a fabric conditioner, liquid scent booster, solid scent booster, liquid detergent, powdered detergent, bar soap, shower gel, hair conditioner, shampoo, hair dye or colourant, dishwashing liquid, hard surface cleaner, toilet block, coated fabric, coated paper, wipe, deodorant, antiperspirant, room deodoriser, cosmetic formulation, fine fragrance, perfume additive bead, foodstuff, beverage, toothpaste, mouthwash, chewing gum, nutraceutical product, or pharmaceutical product.

The consumer product described in various aspects of the present invention may take any form suitable for use. Preferably, the consumer product is in the form of a vapour spray, aerosol, emulsion, lotion, liquid, cream, gel, stick, ointment, paste, mousse, powder, granular product, substrate, or semi-solids.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1a is an optical microscope image of the microcapsule slurry prepared in Example 1 and diluted 10x in single strength buffer.

Figure 1 b is an optical microscope image of the microcapsule slurry prepared in Example 1 , wherein the slurry has been dried onto a glass slide at room temperature for 18 hours and the microcapsules have then been broken by pressing with another glass slide. Figure 2a is an optical microscope image of the microcapsule slurry prepared in Example 2 and diluted 10x in single strength buffer.

Figure 2b is an optical microscope image of the microcapsule slurry prepared in Example 2, wherein the slurry has been dried onto a glass slide at room temperature for 18 hours and the microcapsules have then been broken by pressing with another glass slide.

Figure 3 is an optical microscope image of the microcapsule slurry prepared in Example 3 and diluted 10x in single strength buffer.

Figure 4 is an optical microscope image of the microcapsule slurry prepared in Example 4 and diluted 10x in single strength buffer.

Figure 5 is an optical microscope image of the microcapsule slurry prepared in Example 5 and diluted 10x in single strength buffer.

Figure 6 is an optical microscope image of the microcapsule slurry prepared in Example 6 and diluted 10x in single strength buffer.

Figures 7a and 7b are optical microscope images of the microcapsule slurry prepared in Example 7 at pH 5 and pH 7, respectively, and diluted 10x in single strength buffer.

Figure 8 is an optical microscope image of the microcapsule slurry prepared in Example 8 and diluted 10x in single strength buffer.

Figure 9a is an optical microscope image of the microcapsule slurry prepared in Example 9 and diluted 10x in single strength buffer.

Figure 9b is an optical microscope image of the microcapsule slurry prepared in Example 9, wherein the slurry has been dried onto a glass slide at room temperature for 18 hours and the microcapsules have then been broken by pressing with another glass slide.

Figure 9c is an optical microscope image of the microcapsule slurry prepared in Example 9c and diluted 10x in single strength buffer

Figure 9d is an optical microscope image of the microcapsule slurry prepared in Example 9d and diluted 10x in single strength buffer

Figure 10 is an optical microscope image of the microcapsule slurry prepared in Example 10 and diluted 10x in single strength buffer.

Figure 11 is an optical microscope image of the microcapsule slurry prepared in Example 11 and diluted 10x in single strength buffer.

Figure 12 is an optical microscope image of the microcapsule slurry prepared in Example 12 and diluted 10x in single strength buffer. Figure 13 is an optical microscope image of the microcapsule slurry prepared in Example 13 and diluted 10x in single strength buffer.

Figure 14 is an optical microscope image of the microcapsule slurry prepared in Example 14 and diluted 10x in single strength buffer. Figure 15 is an optical microscope image of the microcapsule slurry prepared in

Example 15 and diluted 10x in single strength buffer.

Figure 16 is an optical microscope image of the microcapsule slurry prepared in Example 8 and diluted 10x in single strength buffer.

Figure 17 is an optical microscope image of the microcapsule slurry prepared in Example 17 and diluted 10x in single strength buffer.

Figure 18 is an optical microscope image of the microcapsule slurry prepared in Example 18 and diluted 10x in single strength buffer.

EXAMPLES

Materials

Fragrance materials

Standard hard water and buffer compositions

1) Hard water for washing This was prepared with the following concentrations of salts in deionised (DI) water:

2) Double strength buffer for gellan gum dilutions

100 ml of double strength buffer solution with preservative were prepared as follows: i. 3.808 g of citric acid monohydrate and 0.552 g of trisodium citrate dihydrate were weighed out; ii. The mixture was completed to 80 g using DI water; iii. The pH of the solution was adjusted to 3 using 1M HCI and 1M NaOH solutions, and the volume of the solution was completed to 100 g with DI water; iv. 0.76 g of CaCh dihydrate was added; v. 0.4 g of sodium benzoate was added; vi. The solution was placed in an ultrasonic bath at 80°C for 5-10 minutes (i.e. until complete dissolution was observed); vii. The solution was allowed to cool down to 20 °C.

3) Single strength buffer for sample storage

100 ml of single strength buffer solution with preservative were prepared as follows: i. 1.904g of citric acid monohydrate and 0.276 g of trisodium citrate dihydrate were weighed out; ii. The mixture was completed to 80 g using DI water; iii. The pH of the solution was adjusted to 3 using 1M HCI and 1M NaOH solutions, and the volume of the solution was completed to 100 g with DI water; iv. 0.38 g of CaCh dihydrate was added; v. 0.2 g of sodium benzoate was added; vi. The solution was placed in an ultrasonic bath at 80°C for 5-10 min (i.e. until complete dissolution was observed); vii. The solution was allowed to cool down to 20 °C. Standard fabric conditioner composition

In some of the following examples, a standard fabric conditioner was employed. This was prepared by mixing the components in Table 1 with an overhead mixer for about 5 minutes at 50°C, then allowing to cool down to 20 °C while mixing.

Table 1

Measurement Methods

Microcapsule Fragrance loading quantification via GC

Fragrance levels in the microcapsule can be determined by extraction of the fragrance and injection into a GC column. An Agilent 8890 gas chromatograph is used, equipped with a HP-5MS column, and using hydrogen as carrier gas. Quantification is achieved by use of a calibration curve for the given fragrance material diluted in ethanol.

To measure the total level of fragrance in an encapsulate sample, the capsules must first be broken by sonication, for example 1.0 g of encapsulate in 2.0 g of DI water with a Bandelin Sonopuls HD4200 ultrasonicator, equipped with probe TS104 for 1 minute at 30% amplitude (around 1.5 KJ in total). A few drops of aqueous potassium hydroxide solution (10%wt) are added before sonication to raise the pH of the solution above 11 . While sonicating, ice is used to keep the temperature below room temperature (20 °C) to avoid any loss of fragrance through evaporation. A microscope is used to check visually if the capsules are fully broken. If not, sonication is repeated. Ethanol is added to the mixture, which is then mixed and centrifuged. The supernatant is collected and retained as the first extraction. The residue is mixed with ethanol again and centrifuged. The supernatant is collected and added to the first extraction. This is then diluted as appropriate and injected into the GC for analysis.

To measure the level of free fragrance in the sample (i.e. the level of unencapsulated fragrance), the encapsulate slurry is well mixed in DI water and filtered using a sterile cell strainer (40 m Nylon mesh). The filtrate is diluted with ethanol and injected into the GC for analysis.

The encapsulated fragrance level is the difference between the total fragrance and the free fragrance levels.

Microcapsule fragrance leakage in fabric conditioner quantification via GC

Fragrance levels in a fabric conditioner can be determined by extraction of the fragrance and injection into a GC column. An Agilent 8890 gas chromatograph is used, equipped with a HP-5MS column, and using hydrogen as carrier gas. Quantification is achieved by use of a calibration curve for the given fragrance. 3.0 g of fabric conditioner is extracted using 3 ml of n-heptane three times. The extraction is achieved with gentle up-and-down hand shaking (30 times x 2) to avoid the formation of an emulsion, and then centrifuged for 10 minutes at 4300 ref. The n-heptane layers are combined, further diluted with n-heptane as appropriate and injected into the GC for analysis.

In order to determine the level of fragrance leakage in fabric conditioner, the microcapsules are mixed into a fabric conditioner formulation, and 10 g aliquots of this mixture are sealed in glass vials (one aliquot per time point). The level of free and total fragrance is measured in each glass vial after being incubated at 37°C for a set period of time.

To measure the level of free fragrance in the sample, the fabric conditioner is filtered using a sterile cell strainer (40 pm Nylon mesh). 3.0 g of the filtrate is extracted using 3 ml of n-heptane three times. The extraction is achieved with gentle up-and-down hand shaking (30 times x 2) to avoid the formation of an emulsion, and then centrifuged for 10 minutes at 4300 ref. The n-heptane layers are combined, further diluted with n- heptane as appropriate and injected into the GC for analysis.

In order to measure the total level of fragrance in a fabric conditioner sample, the encapsulate must first be broken by sonication, for example 5 ml of fabric conditioner, with a Bandelin Sonopuls HD4200 ultrasonicator, equipped with probe TS104 for 1 min at 30% amplitude (around 1.5 KJ in total). While sonicating, ice is used to keep the temperature below room temperature to avoid any loss of fragrance through evaporation. A microscope is used to check visually if the capsules are fully broken. If not, sonication is repeated. 3.0 g of the sonicated fabric conditioner sample is then extracted with 3 ml of n-heptane. The extraction is achieved by gentle up-and-down hand shaking (30 times x 2) to avoid the formation of an emulsion. The sample is centrifuged for 10 minutes at 4300 ref. The supernatant is collected and retained as the first extraction. The residue is mixed again with 3 ml of n-heptane and the extraction is repeated twice more. The three extractions are combined, diluted as appropriate and injected into the GC for analysis.

The leakage level is the percentage of the total fragrance that is present as free fragrance at each point in time. The encapsulated fragrance level after storage, for a given amount of time, is the difference between the total fragrance and the free fragrance levels at that point in time.

Microcapsule slurry olfactive evaluation

For any given encapsulate, the total fragrance level is quantified via GC as described herein. Based on the encapsulate loading the material is diluted to deliver the appropriate level of fragrance for an olfactive assessment. Optionally, preservatives and suspending agents are added to the dilute encapsulate sample.

50 pl of dilute encapsulate is pipetted onto a standard microscope glass slide so that most of the surface area is covered, leaving the edges clear for handling the slide. This is repeated at least four times.

50 pl of dilute encapsulate slurry is also pipetted onto a rectangular fragrance evaluation card blotter (approx. 9 cm x 5 cm). This is repeated at least in duplicate.

Slides were evaluated by trained evaluators at different points in time:

1) Immediately after application;

2) After being left overnight to dry at 20 °C;

3) After being left overnight to dry at 20 °C and then rubbed with a gloved index finger with 10 strokes (in either direction);

4) After being left overnight to dry at 20°C and then pressed with another glass slide for 10 seconds and removed.

Blotters were evaluated by trained evaluators at different points in time:

1) Immediately after application;

2) After being left overnight to dry at 20°C;

3) After being left overnight to dry at 20°C and then rubbed with another clean blotter with 10 strokes (in either direction).

The evaluators graded the strength according to the following scale and provided comments on the character of the fragrance:

Optical microscopy

Optical microscopy images were obtained using an openFrame microscope equipped with a CellCam 200CR camera, Aura Pro phase contrast illuminator and universal plan fluorite objectives at 4x, 10x and 20x.

Microcapsule size measurement by optical microscopy

Particle sizes were taken from the mean size measurements of 50 microcapsules, for each respective sample. The optical microscope was calibrated using the grid of a Hirschmann counting chamber, (Fuchs Rosenthal). Using the straight line tool in Imaged 1.53, particle diameters were measured from two center-edges with the overlay-text feature enabled to avoid repeating capsules.

Example 1 (comparative) - Preparation of delta-damascone microcapsules a) Preparation of protein solution in water

A protein solution was prepared by suspending 10.0 wt% of Pea Protein Isolate (PPI) in 48.9 wt% of DI water and then adding 41.1 wt% of 85 vol% lactic acid. The mixture was ultrasonicated using a Hielscher UIP1000hdT Ultrasonic Homogenizer, until 0.6-0.7 kJ of energy had been delivered per ml of protein dispersion. The temperature was maintained above 80°C using a water bath. b) Preparation of lipophilic phase

The oil phase was prepared by mixing 80% (v/v) of the fragrance material, delta- damascone, and 20% (v/v) of Miglyol® 812 N and cooling to between 0 and 5°C. c) Preparation of external phase

The external phase was prepared by mixing Miglyol® 840 containing 0.5 wt% of PGPR by hand and then placing in a water bath at 53°C for at least 30 minutes. d) Preparation of primary emulsion

A Micropore AXF-1 device with a hydrophilic 10 pm membrane and a 9.5 mm insert was used to produce the primary emulsion of fragrance oil in aqueous protein solution. Flow rates of 80 ml/min of oil phase and 120 ml/min of protein solution (ratio of oil to water phases of 2:3) delivered a uniform, continuous and stable O/W (“oil-in-water”) emulsion with droplet size of approximately 40 pm.

Prior to loading with the protein solution, the Micropore system was passivated with 85% lactic acid and pre-heated for 30 minutes. The protein solution was processed as fast as possible, within about 5 minutes, to prevent its gelation whilst in the Micropore device. e) Preparation of secondary emulsion and microcapsules

The resultant primary emulsion was poured directly into the external phase, at a ratio of primary emulsion to external phase of 1 :4, at a rate of 200 ml/min, into a glass beaker mixed by a Heildolph Hei-TORQUE Core overhead stirrer at 1150 rpm.

The external phase was previously held in a water bath at 53°C, 5°C higher than the gelation point of the primary O/W emulsion. After the addition of primary emulsion was complete, the secondary emulsion was mixed for 2 minutes at 800 rpm without further temperature control. The beaker contents were then cooled in an ice bath, with stirring at 800 rpm for a further 2 minutes. The stirrer speed was then reduced to 500 rpm until 30 minutes after the start of the secondary emulsification. The temperature of the secondary emulsion was below 20°C.

The formed microcapsules were then allowed to fully settle at 4-5°C in the fridge for up to 2 hours. f) Washing of microcapsules

The settled microcapsules were decanted from the external phase and resuspended in hard water at 250 rpm to ensure the external phase was thoroughly removed from the surface of the microcapsules. The suspension was added to a separating funnel and left to sediment for 30 minutes to 1 hour. The sedimented microcapsules were collected at the bottom of the separating funnel. Hard water was added to resuspend the microcapsules in a clean separating funnel and again left to sediment. This procedure was repeated two more times. g) Microcapsule classification

The sedimented microcapsules were sieved through a 250 pm sieve while washing with hard water. The sieved suspension was collected and resuspended in hard water. The washing procedure was repeated a second time. The sedimented microcapsules were then directly sieved through a 38 m sieve while washing with hard water. The microcapsules that remained on the sieve (38 pm < d < 250 pm) were collected and resuspended in hard water in a separating funnel. The sedimented microcapsules were then directly sieved through a 75 pm sieve while washing with hard water. The microcapsules that remained on the sieve (75 pm < d < 250 pm) were collected and resuspended in hard water in a separating funnel. h) Final microcapsules dispersion

The microcapsules were strained on a 40 pm cell strainer, made up to a 50 wt% slurry in single strength buffer and stored at 4-5°C.

An optical microscope picture of the microcapsule slurry prepared without any post-treatment and diluted 10x in single strength buffer is shown in Figure 1a. This shows intact spherical multicore microcapsules.

In Figure 1b the same slurry has been dried onto a glass slide at room temperature for 18 hours and the microcapsules have then been broken by pressing with another glass slide, releasing the encapsulated fragrance oil. This demonstrates the release mechanism so that a fragrance bloom can be noticed from the fragrance encapsulates when they are pressed or rubbed after drying onto a substrate.

The diameter of the microcapsules was measured according to method herein and the average was determined to be 107 pm with a standard deviation of 32 pm.

Fragrance loading analysis was carried out according to the total fragrance loading quantification method described herein. The total delta-damascone loading in the 50 wt% slurry was determined to be 2.1 wt%. modified with

NaTPP

Un-crosslinked microcapsules were prepared as in Example 1 up to step 1e. a) A crosslinking solution of 0.1 M NaTPP and 4.0 wt% Polysorbate 80 was prepared. b) 100 ml of the crosslinking solution was poured over 20 ml of settled microcapsules from Example 1 , step e, after having decanted them from the external phase. The suspension was gently stirred by mechanical agitation at 150 rpm at 20°C for 15 minutes. c) The cross-linked capsules were then washed and made up to a 50wt% slurry according to the process in Example 1 , steps f to h.

An optical microscope picture of the microcapsule slurry diluted 10x in single strength buffer is shown in Figure 2a. This shows intact spherical multicore microcapsules which are visibly very similar to those of Example 1 , indicating that crosslinking with NaTPP has not reduced the structural integrity of the encapsulates.

In Figure 2b the same slurry has been dried onto a glass slide at room temperature for 18 hours and the microcapsules have then been broken by pressing with another glass slide, releasing the encapsulated fragrance oil. This demonstrates the release mechanism so that a fragrance bloom can be noticed from the fragrance encapsulates when they are pressed or rubbed after drying onto a substrate.

Fragrance loading analysis was carried out according to the total fragrance loading quantification method described herein. The total delta-damascone loading in the 50 wt% slurry was determined to be 1 .6 wt%. modified with acidic NaTPP

Un-crosslinked microcapsules were prepared as in Example 1 up to step 1g. a) A crosslinking solution of 0.1 M NaTPP and 4.0 wt% Polysorbate 80 was prepared and was adjusted to pH 3 using 1 M HCI solution. b) 100 ml of the crosslinking solution was poured over 20 ml of settled microcapsules after the supernatant was decanted from Example 1 , step g. The suspension was gently stirred by mechanical agitation at 100 rpm at room temperature for 15 minutes. c) The microcapsules were suspended in a separating funnel and sieved through a 250 pm sieve stacked with a 38 pm one to eliminate any possible aggregate resulting from the crosslinking step. The capsules collected on top of the 38 pm sieve were resuspended in a clean separating funnel in hard water to carry out an additional washing step. The decanted capsules were strained through a 40 pm cell strainer for 5 minutes. Any extra moisture was absorbed with a paper tissue. The strained capsules were diluted with single strength buffer to make a 50 wt% slurry.

An optical microscope picture of the microcapsule slurry diluted 10x in single strength buffer is shown in Figure 3. This shows intact spherical multicore microcapsules which are visibly very similar to those of Example 1 , indicating that the crosslinking with NaTPP has not reduced the structural integrity of the encapsulates.

Fragrance loading analysis was carried out according to the total fragrance loading quantification method described herein. The total delta-damascone loading in the 50 wt% slurry was determined to be 0.9 wt%.

Example 4 (comparative) - Preparation of delta-damascone microcapsules with layer- by-layer deposition of NaTPP-Chitosan-NaTPP

Un-crosslinked microcapsules were prepared as in Example 1 up to step 1g.

2 wt% of chitosan was added to a 2 wt% acetic acid solution and kept under magnetic agitation in a water bath set at 40°C until complete dissolution was observed. The solution was then stored in the fridge overnight.

2 wt% of NaTPP in a 2 wt% acetic acid solution was also prepared and adjusted to pH 3 using acetic acid.

The next day, 5 g of strained microcapsules were resuspended in 200 ml of hard water and put under mechanical agitation at 150 rpm at room temperature.

21.25 g of the NaTPP solution was added to the microcapsule suspension and left to crosslink for 1.5 hours. Then, 35.41 g of the chitosan solution was added dropwise and left to stir for a further 45 minutes. Finally, another 120.40 g of the NaTPP solution was added and left to crosslink overnight.

The crosslinked capsules were then washed according to the process in Example 3 step c.

An optical microscope picture of the microcapsule slurry diluted 10x in single strength buffer is shown in Figure 4. This shows intact spherical multicore microcapsules which are visibly very similar to those of Example 1 , indicating that the layer-by-layer deposition has not reduced the structural integrity of the encapsulates. In addition, the additional layer is visible for the larger capsules.

Fragrance loading analysis was carried out according to the total fragrance loading quantification method described herein. The total delta-damascone loading in the 50 wt% slurry was determined to be 1.0 wt%. This is lower than the loading of the encapsulates of Example 1 as the encapsulate now includes the additional mass of the deposited layers. Example 5 (comparative) - Preparation of delta-damascone microcapsules with complex coacervation with xanthan gum

Un-crosslinked microcapsules were prepared as in Example 1 up to step 1g.

A 0.1 wt% xanthan gum solution was prepared under magnetic agitation in a water bath set at 50°C until complete dissolution was observed. The solution was stored in the fridge overnight to allow for the gum to fully hydrate. The next day, the xanthan gum solution was adjusted to pH 3 using 1 M HCI.

5 g of strained microcapsules were suspended in 200 ml of hard water and adjusted to pH 3 using 1M HCI. The suspension was put under mechanical agitation at 200 rpm at room temperature. 376 g of xanthan gum solution were slowly added while mixing and left to coacervate for 2 hours.

The crosslinked capsules were then subjected to the washing process as outlined in Example 3 step c.

An optical microscope picture of the microcapsule slurry diluted 10x in single strength buffer is shown in Figure 5. This shows intact spherical multicore microcapsules which are visibly very similar to those of Example 1 , indicating that the coacervation has not reduced the structural integrity of the encapsulates. In addition, it is possible to observe some of the coacervate layer on the larger capsules.

Fragrance loading analysis was carried out according to the total fragrance loading quantification method described herein. The total delta-damascone loading in the 50 wt% slurry was determined to be 0.8 wt%. This is lower than the loading of the encapsulates of Example 1 as the encapsulate now includes the additional mass of the coacervate layer.

Example 6 (comparative) - Preparation of delta-damascone microcapsules with complex coacervation with qellan gum

Un-crosslinked microcapsules were prepared as in Example 1 up to step 1g.

A 0.1 wt% high acyl gellan gum solution was prepared under magnetic agitation in a water bath set at 95°C until complete dissolution was observed.

5 g of strained microcapsules were suspended in 200 ml of hard water and placed under mechanical agitation at 200 rpm at 95°C. 414 g of the gellan gum solution were slowly added while mixing and the pH was adjusted to 3 using 1M HCI. Heating was maintained for 30 minutes, then stopped and the suspension was allowed to cool to 20°Cwhile maintaining agitation for 2 hours in total. The crosslinked capsules were then subjected to the washing process as outlined in Example 3 step c.

An optical microscope picture of the microcapsule slurry diluted 10x in single strength buffer is shown in Figure 6. This shows intact spherical multicore microcapsules which are visibly very similar to those of Example 1 , indicating that the coacervation has not reduced the structural integrity of the encapsulates. In addition, it is possible to observe some of the coacervate layer on the larger capsules.

Fragrance loading analysis was carried out according to the total and free fragrance loading quantification method described herein. The total delta-damascone loading in the 50 wt% slurry was determined to be 1.2 wt%. This is lower than the loading of the encapsulates of Example 1 as the encapsulate now includes the additional mass of the coacervate layer. The free fragrance was very low at 0.003 wt%.

Example 7 (comparative) - Preparation of delta-damascone microcapsules with NaHMP

Un-crosslinked microcapsules were prepared as in Example 1 up to step 1g.

A 0.8 wt% NaHMP solution was prepared under magnetic agitation at 20°C. The solution was adjusted to the desired pH (5 or 7) using 1M HCI and 1 M NaOH solutions.

5 g of strained microcapsules were suspended in 150 ml of the 0.8 wt% NaHMP solution, at either pH 5 or 7. The microcapsule suspension was left stirring at 150 rpm for 2 hours. The crosslinked capsules were then subjected to the washing process outlined in Example 3 step c.

An optical microscope picture of the microcapsule slurry diluted 10x in single strength buffer is shown in Figure 7a for the slurry at pH 5 and Figure 7b for the slurry at pH 7. This shows intact spherical multicore microcapsules which are visibly very similar to those of Example 1 , indicating that the crosslinking has not reduced the structural integrity of the encapsulates.

Fragrance loading analysis was carried out according to the total fragrance loading quantification method described herein. The total delta-damascone loading in the 50 wt% slurry was determined to be 2.2 and 2.3 wt% for the pH 5 and pH 7 slurries, respectively.

Example 8 (comparative) - Preparation of delta-damascone microcapsules with Genipin

Un-crosslinked microcapsules were prepared as in Example 1 up to step 1g. 300 mg of genipin were suspended in 10 ml of DI water.

5 g of strained microcapsules were suspended in 290 ml of hard water and the pH was adjusted to 7 using 1 M NaOH. The 10 ml of genipin solution were added to the microcapsule suspension under mechanical agitation at 180 rpm at 40°C, and kept stirring for 2 hours. The microcapsules were allowed to crosslink statically for a further 24 hours at 20°C. The crosslinked capsules were then subjected to the washing process as outlined in Example 3 step c.

An optical microscope picture of the microcapsule slurry diluted 10x in single strength buffer is shown in Figure 8. This shows intact spherical multicore microcapsules which are visibly very similar to those of Example 1 indicating that the crosslinking has not reduced the structural integrity of the encapsulates. The dark colour of the encapsulates is due to the blue pigmentation that confirms that the genipin has covalently bound to the protein shell.

Fragrance loading analysis was carried out according to the total fragrance loading quantification method described herein. The total delta-damascone loading in the 50 wt% slurry was determined to be 0.9 wt%.

Example 9 (comparative) - Preparation of delta-damascone microcapsules with tannic acid

Un-crosslinked microcapsules were prepared as in Example 1 up to step 1g.

A 10 wt% tannic acid solution was prepared by hand shaking and vortexing for a few seconds using a Fisherbrand™ ZX4 IR Vortex Mixer.

5 g of strained microcapsules were suspended in 240 ml of hard water and adjusted to pH 3 using 1M HCI. 6 ml of the tannic acid solution was added to the microcapsule suspension under mechanical agitation at 170 rpm at 50°C, and left stirring for 6 hours. After this time, the suspension was stored in the fridge overnight. The crosslinked capsules were then subjected to the washing process as in Example 3 step c, resulting in brown coloured encapsulates indicating that crosslinking had occurred.

An optical microscope picture of the microcapsule slurry diluted 10x in single strength buffer is shown in Figure 9a. This shows intact microcapsules which are darker than those of Example 1 and wherein the oil multicores are obscured. Without wishing to be bound by theory, it is thought that the binding of the tannic acid to the plant-based protein renders the external surface of the microcapsule practically opaque. In Figure 9b the same slurry has been dried onto a glass slide at room temperature for 18 hours and the microcapsules have then been broken by pressing with another glass slide, releasing the encapsulated fragrance oil. This demonstrates the release mechanism so that a fragrance bloom can be noticed from the fragrance encapsulates when they are pressed or rubbed after drying onto a substrate.

Fragrance loading analysis was carried out according to the total and free fragrance loading quantification method described herein. The total delta-damascone loading in the 50 wt% slurry was determined to be 1 .8 wt% and the free fragrance was very low at 0.003 wt%. with shellac

Un-crosslinked microcapsules were prepared as in Example 1 up to step 1g.

30 g of 25 wt% of shellac solution were diluted in 120 ml of DI water, in a tall form 250 ml glass beaker. Mechanical agitation was started at 350 rpm at RT, using an anchor stirrer.

30 ml of 50% (v/v) of microcapsule slurry were added dropwise to the stirring shellac solution, using a 3 ml transfer pipette. The mixture was left stirring for 30 minutes and stored in the fridge for 3 days. The coated capsules were then subjected to the washing process as in Example 3 step c.

An optical microscope picture of the microcapsule slurry diluted 10x in single strength buffer is shown in Figure 9c. This shows intact microcapsules which appear darker than those of Example 1 and wherein the oil multicores are obscured. They also seemed sandier than uncrosslinked capsules or particles crosslinked with other organic compounds. This indicates that the surface of the encapsulate has been successfully modified by the shellac layer.

Fragrance loading analysis was carried out according to the total fragrance loading quantification method described herein. The total delta-damascone loading in the 50 wt% slurry was determined to be 0.9 wt%.

Example 9b (comparative) - Preparation of delta-damascone microcapsules a combination of tannic acid followed with xanthan coacervation

Tannic acid crosslinked microcapsules were prepared as in Example 9. A 0.1 wt% xanthan gum solution was prepared under magnetic agitation in a water bath set at 60°C until complete dissolution was observed. The solution was stored in the fridge overnight to allow for the gum to fully hydrate. The next day, the xanthan gum solution was adjusted to pH 3 using 1 M HCL

8 g of strained microcapsules from Example 9 were suspended in 400 ml of hard water and adjusted to pH 3 using 1 M HCL The suspension was put under mechanical agitation at 350 rpm at room temperature. 601.6 g of xanthan gum solution were slowly added while mixing and left to coacervate for 1.5 hour.

The crosslinked capsules were then subjected to the washing process as outlined in Example 3 step c.

An optical microscope picture of the microcapsule slurry diluted 10x in single strength buffer is shown in Figure 9d. This shows intact microcapsules which appear darker than those of Example 1 and wherein the oil multicores are obscured. This indicates that the surface of the encapsulate has been successfully modified by at least the tannic acid layer.

Fragrance loading analysis was carried out according to the total fragrance loading quantification method described herein. The total delta-damascone loading in the 50 wt% slurry was determined to be 3.2 wt%.

Example 10 (comparative) - Preparation of delta-damascone microcapsules with glyceraldehyde

Un-crosslinked microcapsules were prepared as in Example 1 up to step 1g.

100 ml of a 0.5 wt% DL-glyceraldehyde solution was prepared and the pH was adjusted to 8 using 1 M NaOH.

5 g of strained microcapsules were suspended in the glyceraldehyde solution and put under mechanical agitation at 140 rpm at 20°C for 24 hours. The crosslinked capsules were then subjected to the washing process outlined in Example 3 step c.

An optical microscope picture of the microcapsule slurry diluted 10x in single strength buffer is shown in Figure 10. This shows intact spherical multicore microcapsules which are visibly very similar to those of Example 1 , indicating that the crosslinking has not reduced the structural integrity of the encapsulates.

Fragrance loading analysis was carried out according to the total and free fragrance loading quantification method described herein. The total delta-damascone loading in the 50 wt% slurry was determined to be 1 .2 wt% and the free fragrance was very low at 0.01 wt%. of delta-damascone microcapsules with

Un-crosslinked microcapsules were prepared as in Example 1 up to step 1g.

A 20 U/ml microbial transglutaminase (m-TG) solution was prepared under magnetic agitation for 10 minutes.

A pH 7 phosphate buffer solution was prepared by dissolving 1.641 g of Na2HPC>4 and 1.014 g of Na^PC in 200 ml of DI water, and adjusting to pH 7 with 1M NaOH.

15 g of strained microcapsules were suspended in 200 ml of phosphate buffer. 1 ml of m-TG solution was added to the suspension under mechanical agitation at 130 rpm in a water bath set at 47°C and left stirring for 2 hours. The crosslinked capsules were then subjected to the washing process as outlined in Example 3 step c.

An optical microscope picture of the microcapsule slurry diluted 10x in single strength buffer is shown in Figure 11. This shows intact spherical multicore microcapsules which are visibly very similar to those of Example 1 , indicating that the crosslinking has not reduced the structural integrity of the encapsulates.

Fragrance loading analysis was carried out according to the total fragrance loading quantification method described herein. The total delta-damascone loading in the 50 wt% slurry was determined to be 2.5 wt%.

Example 12 (comparative) - Preparation of delta-damascone microcapsules with microbial transglutaminase and NaHMP

Un-crosslinked microcapsules were prepared as in Example 1 up to step 1g.

A 20 U/ml microbial transglutaminase (m-TG) solution was prepared under magnetic agitation for 10 minutes.

A pH 7 phosphate buffer solution was prepared by dissolving 1.641 g of Na2HPO4 and 1.014 g of NaH2PO4 in 200 ml of DI water, and adjusting to pH 7 with 1M NaOH. 15 g of strained microcapsules were suspended in 200 ml of phosphate buffer. 1 ml of m-TG solution was added to the suspension under mechanical agitation at 130 rpm in a water bath set at 47°C and left stirring for 2 hours.

The microcapsules were suspended in a separating funnel and sieved through a 250 pm sieve stacked with a 38 pm one to eliminate any possible aggregate resulting from the crosslinking step. The capsules collected on top of the 38 pm sieve were resuspended in a clean separating funnel in hard water to carry out an additional washing step. The decanted capsules were strained through a 40 pm cell strainer for 5 minutes. Any extra moisture was absorbed with a paper tissue.

A 0.8 wt% NaHMP solution was prepared under magnetic agitation at room temperature. The solution was adjusted to pH 7 using 1M NaOH.

5 g of strained microcapsules were suspended in 150 ml of the NaHMP solution and left stirring at 150 rpm for 2 hours. The cross-linked capsules then went through the washing process as in Example 3 step c.

An optical microscope picture of the microcapsule slurry diluted 10x in single strength buffer is shown in Figure 12. This shows intact spherical multicore microcapsules which are visibly very similar to those of Example 1 indicating that the crosslinking has not reduced the structural integrity of the encapsulates.

Fragrance loading analysis was carried out according to the total fragrance loading quantification method described herein. The total delta-damascone loading in the 50 wt% slurry was determined to be 2.4 wt%.

Example 13 (comparative) - Preparation of delta-damascone microcapsules with Polycup™ crosslinking resin

Un-crosslinked microcapsules were prepared as in Example 1 up to step 1g.

0.25 g of crosslinking resin was diluted in 10 ml of DI water.

5 g of strained microcapsules were suspended in 90 ml of hard water and the pH was adjusted to 7 using 1M NaOH. The resin solution was added to the suspension under mechanical agitation at 140 rpm at 90°C, and the mixture was left stirring for 30 minutes. The crosslinked capsules were then subjected to the washing process as in Example 3 step c.

An optical microscope picture of the microcapsule slurry diluted 10x in single strength buffer is shown in Figure 13. This shows intact microcapsules which appear darker than those of Example 1 and wherein the oil multicores are obscured and there is a darker ring around the shell. This indicates that the surface of the encapsulate has been successfully modified by the resin.

Fragrance loading analysis was carried out according to the total fragrance loading quantification method described herein. The total delta-damascone loading in the 50 wt% slurry was determined to be 2.2 wt%.

Example 14 (inventive) - Preparation of delta-damascone “hand-made” microcapsules coated with silica a) Preparation of protein dispersion in water

A protein dispersion was prepared by measuring 1.4 g of Pea Protein Isolate with 8.25 g of DI water in a 50 ml falcon tube and shaking to mix. To this, 5.75 g of 85% lactic acid was added and the resultant mixture was ultrasonicated using a Bandelin Homogenizer, until 1 .0 kJ of energy had been delivered per ml of protein dispersion. b) Preparation of lipophilic phase

The oil phase was prepared by weighing out 6 g of delta damascene. c) Preparation of external phase:

The external phase was prepared by mixing Miglyol® 840 containing 2.0 wt% of PGPR by hand, drying by standing with anhydrous MgSC , filtering with fluted filter paper, and then placing in a water bath at 53°C for at least 30 minutes. d) Preparation of primary emulsion

The oil phase in b) was poured into the protein dispersion from a), the tube was closed and shaken by hand 3 times to mix. e) Preparation of secondary emulsion

300 ml of the Miglyol® 840 from c) was added to a 500 ml beaker. The primary emulsion was poured into the pre-heated Miglyol® 840 and was stirred for 2 minutes at 1000 rpm with no further heating allowing the temperature of the mixture to drop. Stirring was continued for a further 5 minutes at 700 rpm to form the microcapsules. Agitation was reduced to 500 rpm and 15 g of TEOS was added dropwise over 5 minutes. Once addition was completed, stirring was reduced to 300 rpm and left for 4 hours at ambient temperature. The mixture was then cooled on ice for 1 hour to allow the protein to completely gel and the microcapsules to settle. f) Crosslinking with NaTPP

The microcapsules were then crosslinked with NaTPP as described in Example 2 steps a to c. An optical microscope picture of the microcapsule slurry diluted 10x in single strength buffer is shown in Figure 14. This shows intact microcapsules which appear darker than those of Example 1 and wherein the oil multicores are obscured. This indicates that the surface of the encapsulate has been successfully modified by the deposition of silica.

Fragrance loading analysis was carried out according to the total fragrance loading quantification method described herein. The total delta-damascone loading in the 50 wt% slurry was determined to be 0.8 wt%.

Example 15 (inventive) - Preparation of delta-damascone microcapsules coated with silica

A delta damascene primary emulsion was prepared as in Example 1 up to step 1d.

The external phase was prepared as described in Example 14 step c, and maintained at 53°C.

The primary emulsion was poured directly into the external phase, at a ratio of primary emulsion to external phase of 1 :4, at a rate of 200 ml/min, into a glass beaker mixed by a Heildolph Hei-TORQUE Core overhead stirrer at 1150rpm.

After the addition of the primary emulsion was complete, the secondary emulsion was mixed for 5 minutes at 800 rpm without further temperature control so that the mixture began to cool towards room temperature. The beaker contents were then further cooled in an ice bath to speed up the protein gelling and the stirrer speed lowered to 500 rpm to form the microcapsules. Tetraethyl orthosilicate (50 g) was then added dropwise over 5 minutes to the suspension of formed microcapsules. The stirrer speed was lowered to 300 rpm while remaining in ice for 2 h (mixture temperature maintained at <15 °C). The microcapsules were then allowed to fully settle in the ice bath for up to 2 hours.

The capsules were then cross-linked as in Example 2 steps a to c.

An optical microscope picture of the microcapsule slurry diluted 10x in single strength buffer is shown in Figure 15. This shows intact microcapsules which appear darker than those of Example 1 and wherein the oil multicores are obscured. This indicates that the surface of the encapsulate has been successfully modified by the deposition of silica. Fragrance loading analysis was carried out according to the total fragrance loading quantification method described herein. The total delta-damascone loading in the 50 wt% slurry was determined to be 0.6 wt%.

Example 15a (inventive) - Preparation of fragrance microcapsules coated with silica by sodium metasilicate at pH 3

A 25 mL solution of sodium metasilicate (Na2SiO3) was made fresh and the pH adjusted to pH 3 using 1 M HCI. To this, 3 mL of a 50%vol un-crosslinked microcapsule slurry, prepared as in Example 1 , in pH 3 hard water was added directly to the sodium silicate solution. The suspension was mixed at room temperature on a Thermoshaker at 350 rpm for 2 hours. The microcapsules were then drained on a 40 pm cell strainer and rinsed with 200 mL of pH 3 hard water, before resuspension in sodium citrate buffer pH 3.

Fragrance loading analysis was carried out according to the total fragrance loading quantification method described herein. The total delta-damascone loading in the 50 wt% slurry was determined to be 1.6 wt%.

Example 15b (inventive) - Preparation of fragrance microcapsules coated with silica by hydrolysed tetraethyl orthosilicate (TEOS)

0.5 g TEOS (20%wt of dried fragrance microcapsules) was added to 400 g of hard water adjusted to pH 2, and mixed at 150 rpm for 1 min. Then, 5 g of a 50%wt uncrosslinked microcapsule slurry, prepared as in Example 1 , in hard water pH 2 was added to the solution and left to stir for 8 hours at 150 rpm. The coated microcapsules were then drained on a 75 pm sieve and rinsed with hard water (pH 3), followed by resuspension in hard water (pH 3)._

Fragrance loading analysis was carried out according to the total fragrance loading quantification method described herein. The total delta-damascone loading in the 50 wt% slurry was determined to be 2.6 wt%.

Example 15c (inventive) - Preparation of fragrance microcapsules by layer-by-layer deposition of NaTPP/Poly-L-Lysine/Silica by sodium metasilicate Un-crosslinked microcapsules were initially crosslinked with NaTPP as per Example 2. Then, 3.5 g of crosslinked microcapsules were rinsed with 0.05 M Tris-HCI buffer (pH 7.2) and dried before resuspension in 200 mL of a 0.01 %w/v poly-L-lysine solution for 30 min with agitation at 150 rpm. The microcapsules were recovered and washed with Tris-HCI buffer (pH 7.2) before resuspension in 200 mL of a 20 mM sodium metasilicate solution (pH 7) for 2 hours at 150 rpm. NaTPP/poly-l-lysine/silica microcapsules were collected and washed with hard water (pH 3) before resuspension in citrate buffer with preservative.

Fragrance loading analysis was carried out according to the total fragrance loading quantification method described herein. The total delta-damascone loading in the 50 wt% slurry was determined to be 1.6 wt%.

Example 16 (comparative) - Preparation of fragrance microcapsules coated with silver

Crosslinked microcapsules were prepared as in Example 2 and then washed with DI water to remove the single strength buffer.

To 0.73 g of strained microcapsules was added 8 ml of DI water and 4 ml of equimolar AgNCh/glucose (200 mM) solution and the mixture left to stir mechanically for 2 minutes at 100 rpm. Then, 8 ml of 0.1 M Na2COs was slowly added to the mixture dropwise and left to stir at 100 rpm for 1 h. Microcapsules were washed with hard water and made into a 50 wt% slurry in single strength buffer.

An optical microscope picture of the microcapsule slurry diluted 10x in single strength buffer is shown in Figure 16. This shows intact microcapsules which appear darker than those of Example 1 and wherein the oil multicores are obscured. This indicates that the surface of the encapsulate has been successfully modified by the deposition of silver.

Fragrance loading analysis was carried out according to the total fragrance loading quantification method described herein. The total delta-damascone loading in the 50 wt% slurry was determined to be 1 .1 wt%.

Example 17 (inventive) - Preparation of fragrance microcapsules coated with silica and silver

Silica coated microcapsules were prepared as in Example 15 and then washed with DI water to remove the single strength buffer. To 8 ml of a 50 vol% slurry of silica coated microcapsules was added 4 ml of equimolar AgNCh/glucose (200 mM) solution and the mixture left to stir mechanically for 2 minutes at 100 rpm. Then, 8 ml of 0.1 M Na2COs was slowly added to the mixture dropwise and left to stir at 100 rpm for 1 h. Capsules were washed with hard water and made into a 50 wt% slurry in single strength buffer.

An optical microscope picture of the microcapsule slurry diluted 10x in single strength buffer is shown in Figure 17. This shows intact microcapsules which appear even darker than those of Example 15. This indicates that the surface of the encapsulate has been successfully further modified by the deposition of silver.

Fragrance loading analysis was carried out according to the total fragrance loading quantification method described herein. The total delta-damascone loading in the 50 wt% slurry was determined to be 0.6 wt%.

Example 18 (comparative) - Preparation of fragrance microcapsules containing internal silica layer

A protein solution was prepared as in Example 1 step a. An oil phase containing tetraethyl orthosilicate was prepared by mixing 80% (w/w) of the fragrance material, delta-damascone, 15% (w/w) of Miglyol® 812 N and 5 % (w/w) of tetraethyl orthosilicate (TEOS), and cooling to between 0 and 5°C.

The oil phase, already containing the TEOS, was encapsulated as in Example 1 steps c to e, then crosslinked as in Example 2 steps a to c.

An optical microscope picture of the microcapsule slurry diluted 10x in single strength buffer is shown in Figure 18. This shows intact microcapsules which appear darker than those of Example 1 and wherein the oil multicores are no longer visible in some cases. This indicates that an internal layer of silica has been successfully formed within the microcapsule.

Fragrance loading analysis was carried out according to the total fragrance loading quantification method described herein. The total delta-damascone loading in the 50 wt% slurry was determined to be 1 .1 wt%.

Example 19 (comparative) - Fragrance microcapsules

A lipophilic phase of delta-damascone and Miglyol® 812 N was encapsulated according to the process in Examples 1 and 2 but with variations to the ratio of fragrance material to solvent in the primary emulsion, the amount of sonication energy inputted to the PPI solution and the level of PGPR in the external phase.

In the final washing stage of the process the capsules were filtered down to a specified size range as shown in Table 2 and prepared as a 50 vol% slurry in single strength buffer and analysed for total fragrance loading according to the method herein described.

Table 2

The results show that the process conditions can be optimised to deliver encapsulates with different loading levels for a given fragrance material. For delta- damascone, the highest loading was achieved with the higher sonication energy, the lowest level of PGPR, using a lower level of Miglyol® 812 N in the lipophilic phase and filtering off the finer particles.

Example 20 - Stability of fragrance microcapsules in fabric conditioner

Fragrance microcapsules were added to a simple unperfumed fabric conditioner formulation to test the stability of the microcapsules in this very challenging environment, which is believed to be due to the combination of a surfactant and a low viscosity product with high water availability.

The fabric conditioner was prepared as described above. For each microcapsule to be tested, the amount added to the unperfumed fabric conditioner was calculated according to its loading so that the level of fragrance was around 0.1 wt% for each stability test. Fabric conditioner samples containing the microcapsules of Examples 1 , 15, 15a, 15c, 16 and 18 were placed in an incubator at 37°C and the free and total fragrance in the fabric conditioner was measured via the methods herein described immediately after mixing with the fabric conditioner and after 4 or 24 hours in the incubator. The fragrance leakage was calculated as free fragrance as a percentage of total fragrance loading for each encapsulate. The initial level of free fragrance in the slurry for these encapsulates was negligible and could be ignored in this stability test. The results are shown in Table 3.

Table 3

The results show that the un-crosslinked microcapsules of Example 1 (comparative) started to leak fragrance as soon as they were mixed into the fabric conditioner, and after 4 hours they had lost 88% and after 24 hours 90% of the encapsulated fragrance.

Post-treatment with a silicon-containing compound of Example 15 reduced the leakage from the inventive microcapsules immediately after mixing and to 39% after 4 hours. This inventive microcapsule provided immediate protection from leakage in fabric conditioner demonstrating that the encapsulates could be dosed into a fabric conditioner for immediate usage either manually or automatically within a washing machine. Example 18 (comparative), where the silicon-containing compound is inside the microcapsule and not added as a treatment post-microcapsule formation, was poorer performing with 49% loss of the encapsulated fragrance after 4 hours. Example 16 (comparative), where the post-treatment is with a metal rather than a silicon-containing compound, was poorer performing with a 73% loss of the encapsulate fragrance after 4 hours.

After 24 hours, post-treatment with a silicon-containing compound of Examples 15, 15a and 15c all reduced the leakage from the inventive microcapsule to 61 %. These inventive microcapsules provided greater resistance to leakage in fabric conditioner and have the potential to be used in a fabric conditioner application to deliver a scent bloom.

Example 18 (comparative), where the silicon-containing compound is inside the microcapsule and not added as a treatment post-microcapsule formation, was poorer performing with 82% loss of the encapsulated fragrance after 24 hours. : Formation of interfacial polymerisation shell

An optional thin polymeric shell may be formed as part of the encapsulate wall in order to provide the plant-based protein microcapsule with an additional barrier to prevent diffusion of the lipophilic components out of the encapsulate and into the external environment. As the structural integrity of the encapsulate is provided by the plant-based protein, this polymeric shell can be very thin. The polymeric shell is created by the in situ reaction between polyisocyanate and diamine. Two possible processing routes to achieve this are discussed below.

Interfacial polymerisation initiated after the secondary emulsification

A first crosslinking agent, such as polyisocyanate, is introduced into the lipophilic phase at a level of 1-20 wt% of said phase before forming the primary emulsion.

The microcapsules are formed following the double emulsification process as described herein, optionally followed by a covalent crosslinking step.

The microcapsule dispersion can be adjusted to pH 7 using either HCI or NaOH solutions. A 3 wt% aqueous solution (pH 7) of the second crosslinking agent, such as diamine, is added at 20°C to the microcapsule dispersion in an equimolar proportion compared to the polyisocyanate, and at a rate of 1 ml/min, using a syringe pump, to induce polymerisation. The mixture is then kept stirring for 2 hours at 20 °C. The capsules are then left to sediment in the external oil at 4-5°C and optionally further processed (e.g. washed and crosslinked according to the processes described herein). initiated after emulsification/before the emulsification

A first crosslinking agent, such as polyisocyanate, is introduced into the lipophilic phase at a level of 1-20 wt% of said phase before forming the primary emulsion.

A diamine is added to the PPI solution in an equimolar proportion compared to the amount of polyisocyanate after having fully dissolved the protein in the lactic acid aqueous solution.

The primary emulsion is then formed as per the process described herein.

The process for double emulsion formation is modified in that the external phase is maintained in a water bath heated up to 90°C. After forming the double emulsion, it is stirred for 10 minutes at 90°C to allow for curing, and then allowed to cool down to 20 °C. It is then further cooled down to 15-10°C, using ice, over 1 hour. Alternatively, the mixture is cooled down from 90 to 10°C at a controlled rate of 0.2-0.3°C/min.

The capsules are then left to sediment in the external oil at 4-5°C and optionally further processed (e.g. washed and crosslinked according to the processes described herein).