MUCILAGE GUM

TECHNICAL FIELD OF THE INVENTION

The present invention relates to an edible oil-in-water emulsion that comprises a small quantity of ground pulse seed in combination with seed mucilage gum. Examples of edible emulsions encompassed by the present invention include mayonnaise, dressings, soups, sauces, dips and drinks.

The invention also provides a process for the manufacture of the aforementioned oil-in-water emulsion.

BACKGROUND OF THE INVENTION

The emulsion stability of oil-in-water emulsions is affected adversely by a number of different changes that may occur in the structure of these emulsions as time progresses.

There are basically five ways in which the structure of an emulsion of liquid droplets in a continuous medium can change: 1 . Creaming/Sedimentation: No change in droplet size (or droplet size distribution), but build-up of an equilibrium droplet concentration gradient within the emulsion. This phenomenon results from external force fields, usually gravitational, acting on the system. "Creaming" is the special case in which the droplets collect in a concentrated layer at the top of an emulsion. "Sedimentation" occurs when the droplets collect in a concentrated layer at the bottom of the emulsion.

2. Flocculation: Again, no change in basic droplet size or distribution but the build-up of aggregates of droplets within the emulsion. The individual droplets retain their identity. This process of flocculation results from the existence of attractive forces between the droplets. 3. Coalescence: Flocculated droplets in the bulk of the emulsion, or alternatively, droplets within a close-packed array resulting from sedimentation or creaming, coalesce to form larger droplets. This results in a change of the initial droplet size distribution. The limiting state here is the complete separation of the emulsion into the two immiscible bulk liquids. Coalescence thus involves the elimination of the thin liquid film (of continuous phase) which separates two droplets in contact in an aggregate or a close-packed array. The forces to be considered here are therefore the forces acting within thin-liquid films in general. 4. Ostwald ripening: An alternative way in which the average droplet size in an emulsion can increase, without the droplets coalescing, occurs if the two liquids forming the disperse phase and the continuous phase, respectively, are not totally immiscible. This is the case in reality because all liquid pairs are mutually miscible to some finite extent. If one starts with a truly monodisperse emulsion system, then no effects arising from this mutual solubility will arise. However, if the emulsion is polydisperse, larger droplets will form at the expense of the smaller droplets owing to the process known as Ostwald Ripening. In principle, the system will tend to an equilibrium state in which all the droplets attain the same size (this may be, of course, that state when we have just one single large drop). The process of Ostwald ripening results from the difference in solubility between small and large droplets.

5. Phase inversion: A further way in which the structure of an emulsion may change is for the emulsion to "invert", e.g. for an o/w emulsion to change to a w/o emulsion. This may be brought about by a change in temperature or concentration of one of the components or by the addition of a new component to the system.

6. Syneresis: Yet another way in which emulsions may change is the separating off of one of the main liquid components of the emulsion. In oil-in-water emulsions both oil syneresis and water syneresis may occur.

If oil-in-water emulsions are stored for prolonged periods of time under varying temperature conditions, as is the case for retail products such as dressings and mayonnaise, the aforementioned destabilizing processes have to be slowed down. In order to achieve this, emulsifiers and water structuring agents are commonly employed in these emulsions. Phospholipids are an example of an emulsifier that is widely used to stabilize oil-in-water emulsions. Egg yolk contains appreciable levels of phospholipids and is widely used as an oil-in-water emulsifier, e.g in mayonnaise and dressings. Examples of water structurants include modified celluloses, starches (modified or non- modified), gums such as xanthan, agar, gelatin, carrageenan (iota, kappa, lambda), Gellan, galactomannans (guar, tara, cassia, LBG), konjac glucomannan, gum arabic, pectins, milk proteins, alginate, chitosan and cellulosic fibres. The use of the latter water-structuring agents in edible oil-in-water emulsions has the disadvantage that consumers regard these ingredients as undesirable additives. Hence, it would be desirable if stable acidified oil-in-water emulsions could be produced without such water-structuring agents. US 7,029,719 describes a mayonnaise-like food made of concentrate bean curd, being an edible emulsified matter prepared by mixing and emulsifying bean curd, vinegar, seasoning, spice, emulsifier, and vegetable oil, in which the bean curd is concentrated bean curd prepared by coagulating a concentrated soybean milk at Brix concentration of 15 or more by use of a coagulant. Example 9 describes a mayonnaise having an oil content of 60 wt.% that contains 10 wt.% concentrated bean curd and no conventional water structurant.

WO 99/51 106 describes oil-and-water emulsions that are stabilized by lupin protein compositions. Lupin protein is said to confer the ability to stabilize emulsions at a higher ratio of oil than is possible with soy protein, and the emulsifying properties approach or even I exceed those obtainable with animal-derived proteins (such as caseinates).

SUMMARY OF THE INVENTION The inventors have found that very stable oil-in-water emulsions containing 30-95 wt.% of a continuous aqueous phase and 5-70 wt.% of a dispersed oil phase can be produced without using conventional water structurants or emulsifiers by incorporating into said emulsion 0.1 - 10% of finely ground pulse seed calculated as % dry matter by weight of the aqueous phase and 0.005-0.4% of rhamnogalacturonan mucilage gum by weight of the aqueous phase, said rhamnogalacturonan mucilage gum being a polysaccharide having a backbone composed of (1→4)-linked β-D-galacturonopyranosyl and (1→2)-linked oL-rhamnopyranosyl residues. .

Although the inventors do not wish to be bound by theory, it is believed that the starch and fiber from the ground pulse seed provides water structuring properties and that the proteins contained therein provide emulsifying properties and that the balance between these water structuring and emulsifying properties. In order to enable the starch, fibers and proteins to exert these effects within the oil-in-water emulsion, these biopolymers need to be released and hydrated. This is achieved by employing pulse seeds in finely ground form.

The inventors have further found that rhamnogalacturonan mucilage gum, such as the mucilage gum found in mustard bran, further contributes to the stability of the oil-in-water emulsion. Thus, the combined use of ground pulse seed and rhamnogalacturonan mucilage gum in the indicated concentrations ensures that the oil-in-water emulsion remains stable during prolonged storage under ambient conditions. The rhamnogalacturonan mucilage gum may be introduced in the present emulsion in the form of a crude mucilage gum containing ingredient such as mustard bran. The rhamnogalacturonan mucilage gum can also be introduced in a more refined form, e.g. as an aqueous extract of mustard bran.

Yellow or white mustard (Sinapsis alba, L.) is known to contain much higher amounts of mucilagous materials in the seed coat than any other type of mustards. The mucilage material can be extracted from yellow mustard seed or seed coat (bran) by water at room or elevated temperatures. The crude mucilage contains 80-94% carbohydrates, mainly composed of glucose (22-35 wt.%), galactose (1 1 -15 wt.%), mannose (6.0-6.4 wt.%), rhamnose (1.6-4.0 wt.%), arabinose (2.8-3.2 wt.%) and xylose (1.8-2.0 wt.%). The water- soluble fraction of yellow mustard mucilage is a heterogeneous mixture containing both neutral and acidic polysaccharides in roughly equal amounts.

US 2006/029703 describes a process for single-stage drying and grinding of mustard bran. It is observed in the US patent application that the mustard bran may be used as a water- binding food additive. It is further stated therein that the gums naturally present in mustard bran act as an excellent water binder.

US 2008/003238 describes compositions comprising 0.1 to 35% yellow mustard gum by weight wherein the balance of the composition is selected from the group consisting of: water, oil in water emulsion, water in oil emulsion, beverage, juice, sauce, milk, milk derivatives, wine, liquors, alcohol, spirit, esters, soluble and insoluble, edible and inedible compounds, a gel of water, oil and solids, a paste of water, oil and solids, a dry mix of other solid compounds. The yellow mustard gum is said to have excellent emulsifying, suspending and rheological properties. Examples 6.5 to 6.8 describe mayonnaise products containing yellow mustard gum. The present invention also provides a process of preparing the aforementioned oil-in-water emulsion, said process comprising combining:

• finely ground pulse seed;

• seed mucilage component containing at least 3% by weight of dry matter of the

aforementioned rhamnogalacturonan mucilage gum;

· water;

• oil; and

• optionally further ingredients.

DETAILED DESCRIPTION OF THE INVENTION

Accordingly, one aspect of the invention relates to an edible oil-in-water emulsion

comprising:

• 30-95 wt.% of a continuous aqueous phase;

· 5-70 wt.% of a dispersed oil phase comprising 80-100 vol.% of oil droplets having a

diameter of less than 20 μηη;

wherein the emulsion contains 0.1 -10% of finely ground pulse seed calculated as % dry matter by weight of the aqueous phase; and 0.005-0.4% of rhamnogalacturonan mucilage gum by weight of the aqueous phase, said rhamnogalacturonan mucilage gum being a polysaccharide having a backbone composed of (1→4)-linked β-D-galacturonopyranosyl and (1→2)-linked a-L-rhamnopyranosyl residues.

The term "dietary fiber" as used herein refers to indigestible non-starch polysaccharides such as arabinoxylans, cellulose, lignin, pectins and beta-glucans.

The term "sugars" as used herein refers to mono- and disaccharides.

The term "protein" as used herein refers to a linear polypeptide comprising at least 10 amino acid residues. Preferably, said protein contains more than 20 amino acid residues. Typically, the protein contains not more than 35,000 amino acid residues. The term "oil" as used herein refers to lipids selected from the group of triglycerides, diglycerides, monoglycerides and free fatty acids. The term "oil" encompasses lipids that are liquid at ambient temperature as well as lipids that are partially or wholly solid at ambient temperature.

The contents of 'dietary fiber', 'sugar', 'protein', 'starch', 'fat' mentioned in this invention are determined according to the standards used by the U.S. Department of Agriculture,

Agricultural Research Service. 2010. USDA National Nutrient Database for Standard Reference, Release 23.

The term "diameter" as used herein in relation to the droplet size of the dispersed oil phase, unless otherwise specified, refers to the diameter as determined with the help of confocal laser scanning microscopy. The "finely ground pulse seed" of the present invention is suitably produced by milling or grinding dehulled or non-dehulled pulse seeds. The pulse seeds may be milled or ground as such, or they may be milled or ground in the presence of water, e.g. to produce an aqueous slurry or paste. The requirement that the present emulsion contains 0.1 -10% of finely ground pulse seed, calculated as dry matter, by weight of aqueous phase should be construed as:

0.1 % < (parts by weight of dry matter of finely ground pulse seed)/(parts by weight of aqueous phase) < 8%; wherein the aqueous phase, besides water, includes the part of the finely ground pulse seed that is contained therein, as well as other components (e.g.

acidulant) that are contained therein.

The elastic modulus G' is the mathematical description of an object or substance's tendency to be deformed elastically (i.e., non-permanently) when a force is applied to it. The elastic modulus of an object is defined as the slope of its stress-strain curve in the elastic deformation region: A = stress/strain

wherein lambda (λ) is the elastic modulus; stress is the restoring force caused due to the deformation divided by the area to which the force is applied; and strain is the ratio of the change caused by the stress to the original state of the object. The elastic modulus of an oil- in-water emulsion is suitably determined by oscillatory measurements, performed at 20°C using a plate-plate geometry (plate: 4 cm diameter, 1 mm gap) at a frequency of 1 Hz in the oscillatory stress interval from 0.01 Pa to 1768 Pa (a stress sweep). Herein, the G' (Pa) is taken at plateau value (linear region). Unless indicated otherwise, the term "viscosity" refers to the viscosity of the present emulsion at 10 s ^"1 and 20°C. This viscosity is suitably determined with a Haake Rheometer (Rotovisco RV20) using a set of concentric cylinders (or bob-in-cup) with a 1 mm gap, the bob having a diameter of 1 .0 cm and length of 1 .0 cm. The inner cylinder or bob starts rotating from 0 shear and ramps up to a shear rate of 134 sec ^"1 in 542 sec. By way of comparison, the viscosity values refer to the shear rate of 10 sec ^"1 .

According to a particularly preferred embodiment, the ground pulse seed in the present emulsion is obtained from pulse seed having the following composition, calculated on dry matter:

· 30-60 wt.% of starch;

• 1 -40 wt.% of dietary fiber;

• 0.5-12 wt.% of sugars;

• 15-35 wt.% of protein;

• 0.8-12 wt.% of oil.

Typically, starch, dietary fiber, sugars, protein and oil together make up 90-100 wt.%, more preferably 95-100 wt.% of the dry matter contained in the pulse seed.

Even when used in relatively low concentrations, the finely ground pulse seed of the present invention is capable of substantially improving the stability of the oil-in-water emulsion.

Accordingly, the finely ground pulse seed preferably represents not more than 9%, more preferably not more than 8%, most preferably not more than 7% of the oil-in-water emulsion, calculated as dry matter by weight of aqueous phase. Typically, the finely ground pulse seed is employed in a concentration of at least 0.1 %, even more preferably of at least 0.5% and most preferably of at least 1 .5%, where the percentages are again calculated as dry matter by weight of the aqueous phase.

The composition of the pulse seeds employed in the present emulsion is critically important to achieving the desired emulsion stability. Especially the balance between the amount of protein and starch comprised in the finely ground pulse seed is deemed to be of great importance. The composition of the finely ground pulse seed as comprised in the present emulsion is essentially identical to the composition of the pulse seed as defined herein. The finely ground pulse that is employed in accordance with the present invention may be obtained from dehulled and/or non-dehulled pulse seed. The water-structuring and emulsifying properties of the finely ground pulse seed are believed to be largely attributable to the starch and protein components. Since the hulls of pulse seed predominantly consist of dietary fibre, dehulling does not significantly affect the functionality of the finely ground seed in the present emulsion. Preferably, the finely ground pulse seed employed is obtained from dehulled pulse seed. According to a particularly preferred embodiment, the pulse seed comprised in the oil-in- water emulsion contains starch and protein in a weight ratio of 2:3 to 3:1 , more preferably of 1 :1 to 5:2, most preferably in a weight ratio of 1 :1 to 2:1.

According to another preferred embodiment, the pulse seed comprised in the oil-in-water emulsion contains starch and dietary fiber in a weight ratio of 3:10 to 12:1 , most preferably in a weight ratio of 1 :2 to 8:1.

Typically, the pulse seed contains less than 25%, most preferably less than 20% of dietary fiber by weight of dry matter.

The oil content of the pulse seed preferably lies in the range of 0.8-8 wt.%.

Globulins and albumins typically represent a major part of the protein contained in the pulse seed. Accordingly, in a preferred embodiment, globulins and albumins represent at least 50 wt.%, more preferably 55-95 wt.% and most preferably 60-90 wt.% of the protein contained in the pulse seed.

Emulsions of particular good quality can be obtained if the pulse seed contains globulins and albumins in a weight ratio that lies within the range of 10:1 to 1 :1 , or even more preferably in a weight ratio of 7:1 to 2:1.

In accordance with another preferred embodiment the globulins legumin and vicilin together represent at least 35 wt.%, more preferably 40-75 wt.% and most preferably 45-70 wt.% of the protein comprised in the pulse seed. The protein glutelin preferably represents 5-30 % by weight, more preferably 8-25 % by weight of the protein comprised in the pulse seed.

The content of globulin, albumin, legumin, vicilin, and glutelin in the pulse seeds of the present invention is suitably determined by the method described by Gupta & Dhillon [Gupta, R., & Dhillon, S. 1993. Characterization of seed storage proteins of Lentil (Lens culinaris M.). Annals of Biology, 9, 71 -78].

The protein provided by the finely ground pulse seed preferably comprises not more than a minor amount of sizeable coagulated protein aggregates. Typically, the finely ground pulse seed comprises 0-1 wt.% of coagulated protein aggregates having a hydrated diameter of at least 1.0 μηη. The hydrated diameter can suitably be determined by Confocal Scanning Laser Microscopy with Nile Blue as fluorescent dye. The protein provided by the pulse seed preferably is largely denatured, e.g. as a result of heat treatment. Preferably, 60-100 wt.%, more preferably at least 90-100 wt.% of the protein comprised in the finely ground pulse seed is denatured.

The starch provided by the finely ground pulse seed preferably is largely gelatinized .

Preferably 50-100 wt.%, more preferably 70-100 wt.% and most preferably 90-100 wt.% of the starch contained in the emulsion is gelatinized. Gelatinized starch is believed to enhance the emulsion stability by structuring the continuous aqueous phase of the emulsion. The extent to which the starch present in the emulsion is gelatinized can suitably be determined by cross polarised light microscopy.

The finely ground pulse seed comprised in the present emulsion is advantageously obtained from a pulse selected from lentils, chickpeas, beans and combinations thereof. Even more preferably, the finely ground pulse seed is obtained from a pulse selected from lentils, chickpeas, mung beans and combinations thereof. Most preferably, the finely ground pulse seed is finely ground lentils.

As explained herein before, it is important that the pulse seed is finely ground in order to release starch, protein and dietary fiber from the seed material. Advantageously, the finely ground pulse seed contains less than 10 wt.%, more preferably less than 5 wt.% and most preferably less than 1 wt.% of particles having a hydrated diameter of 200 μηη or more. The hydrated diameter of the finely ground pulse seed is suitably determined by means of Confocal Scanning Laser Microscopy, using the fluorescent dye Acridine Orange.

The inventors have found that the pulse seed protein plays an important role in structure formation and that it can seriously influence the rheology of the emulsion. This is in line with microscopy observations which show that these proteins form "bridges" between adjacent oil droplets, leading to the formation of an aggregated oil-droplet network and increased product thickness. Furthermore, this finding was confirmed by experiments in which emulsions according to the present invention were treated with protease. Treatment of the present emulsion with protease resulted in a significant decrease of product thickness that could be quantified by measuring the drop in G' and viscosity that resulted from this treatment.

Typically, protease treatment of an oil-in-water emulsion according to the present invention results in a reduction of G' of more than 40%, more preferably of more than 60% and most preferably of more than 70%. The same protease treatment of the present emulsion typically results in a viscosity decrease of more than 30%, more preferably of more than 50% and most preferably of more than 60%.

The protease treatment as referred to herein is suitably carried out according to the following protocol:

• if pH of the emulsion is less than 5.1 , adjust pH of the emulsion to pH 5.1 using 1 N

NaOH;

• add a botanical protease solution (Promod™ 144GL, Biocatalysts Ltd, UK) to the

emulsion at a level of 0.5 wt% and thoroughly mix it into the emulsion by hand;

· incubate the emulsion at 40 °C for 24 hrs;

• treat control samples (without protease) in the same way; but using 0.5 wt% Millipore;

• following incubation, store the samples at 5 °C for 3 weeks before rheological

characterisation. According to a particularly preferred embodiment the present emulsion contains 0.01 -0.2%, more preferably 0.01 -0.1 % by weight of the aqueous phase of the rhamnogalacturonan mucilage gum.

The rhamnogalacturonan mucilage gum in the present emulsion preferably is a pectic-like acidic polysaccharide with side branches that are attached to the backbone, consisting mainly of β-D-Galp and 4-0-Me-3-D-GlcpA. Preferably, the acidic polysaccharide has the following structure (a) (taken from Izydorczyk M, Cui SW, Wang Q. In: Cui SW, editor, Food carbohydrates: chemical an physical properties and applications. Boca Raton: CRC Press; 2005. p. 263-308).

Besides the rhamnogalacturonan mucilage gum the present invention advantageously contains a non-pectic neutral polysaccharide that is abundantly present in e.g. mustard bran. Preferably, the emulsion contains 0.005-0.4%, more preferably 0.01 -0.3% and most preferably 0.02-0.2% by weight of the aqueous phase of a (1→4)linked β-D-glucose backbone; wherein at least some, preferably at least 0.1 % of the 0-2, 0-3, and 0-6 atoms of the glucose residues in the backbone carry ethyl or propyl ether groups. Preferably, the non- pectic neutral polysaccharide has the following structure (b) (also taken from Izydorczyk et al. (2005).

4-O-Me-D-GicA

1 R

\ 6 I i

P-D-Galp P-D-Galp

l 1

4 \ 4 I — * ^■ 2>-ra-L-Rfiap- (1— >► 4)-«-D-GalA-(1— »>2}-o -i-Ra >-(1— »- 2)-r/.L-Rhap-{1— 4)-« -D-GalA -(1

R = 4 -O-Me-p-D-GicA- «~6> -(i-D-Galp -d (Mostly)

or 4 -O-M«.p-0-Gl€A-(t * 2) -p-D-Ga!p -( 1 (Occasionally)

The rhamnogalacturonan mucilage gum and the non-pectic neutral polysaccharide are preferably present in the oil-in-water emulsion in a weight ratio of 1 :5 to 5:1 , more preferably of 3:1 to 1 :3 and most preferably of 2:1 to 1 :2.

According to another preferred embodiment, the rhamnogalacturonan mucilage gum, and even more preferably both said mucilage gum and the aforementioned neutral polysaccharide originate from a plant belonging to the family Brassicaceae. Even more preferably, the rhamnogalacturonan mucilage gum originates from mustard mustard, notably yellow mustard. The mucilage gum contained in the present emulsion may suitably be provided by mustard bran and/or an extract of mustard bran. Aqueous extracts of mustard bran offer the advantage that water-insoluble components of the mustard bran have been removed. In some applications the presence of these water-insoluble components is undesirable, e.g. because they can adversely affect the appearance of the product.

The present emulsion may contain other components of mustard seed besides mustard mucilage gum. Preferably, the emulsion contains substantially more mustard bran than mustard seed The present emulsion preferably contains at least 0.1 wt.%, more preferably at least 0.15 wt.% and most preferably 0.2-10 wt.% of an acidulant selected from acetic acid, citric acid, lactic acid, malic acid, phosphoric acid, hydrochloric acid, glucono-delta-lactone and combinations thereof. Even more preferably, the emulsion contains 0.2-10 wt.% of an acidulant selected from acetic acid, citric acid and combinations thereof. Most preferably, the emulsion contains 0.2-10 wt.% of acetic acid.

The dispersed oil phase typically contains 50-100 wt.%, more preferably 70-100 wt.% and most preferably 90-100 wt.% of triglycerides. The oil phase advantageously contains a high level of unsaturated fatty acids. Typically, 40-100 wt.%, more preferably 50-100 wt.% and most preferably 60-100 wt.% of the fatty acids contained in the dispersed oil phase are unsaturated fatty acids. The melting point of the dispersed oil phase typically does not exceed 30°C, more preferably it does not exceed 20°C and most preferably it does not exceed 10°C. Examples of oils that may be employed in the oil phase of the present emulsion include those which are liquid at ambient temperature like avocado, mustard, cottonseed, fish, flaxseed, grape, olive, palm, peanut, rapeseed, safflower, sesame, soybean, sunflower, mixtures thereof and the like. Examples of oils that solid at ambient temperature and suitable for use in accordance with this invention include butter fat, cocoa butter chicken fat, coconut oil, palm kernel oil mixtures thereof and the like. The present invention also encompasses the use of olein and/or stearin fractions of the aforementioned oils. The dispersed oil phase comprised in the present emulsion preferably represents at least 20 wt.%, more preferably at least 30 wt.% and most preferably at least 35 wt.% of the emulsion. The continuous aqueous phase preferably represents not more than 80 wt.%, more preferably not more than 70 wt.% and most preferably not more than 65 wt.% of the emulsion.

Typically, 80-100 vol.% of the oil droplets contained in the present emulsion have a diameter of less than 15 μηη, more preferably of 0.5-10 μηη.

The edible emulsion may suitably contain one or more additional ingredients besides water, oil and ground pulse seed. Examples of such optional ingredients include acidulant, salt, spices, vitamins, flavouring, colouring, preservatives, antioxidants, chelators herbs and pieces of meat, vegetable or cheese. Such optional additives, when used, collectively, do not make up more than 40%, more preferably not more than 20% by weight of the emulsion.

The edible emulsion of the present invention can be stabilized very effectively without using modified starch. Hence, in a preferred embodiment, the emulsion contains no modified starch. The term "modified starch" as used herein refers to an enzymatically or chemically treated starch.

The finely ground pulse seed of the present invention enables the production of stable oil-in- water emulsions without the need of using conventional water structuring agents.

Consequently, in accordance with an especially advantageous embodiment of the invention, the emulsion contains no added water structuring agent selected from modified cellulose, modified starch, xanthan, agar, gelatin, carrageenan (iota, kappa, lambda), Gellan, galactomannans (guar, tara, cassia, LBG), konjac glucomannan, gum arabic, pectins, alginate and chitosan. The finely ground pulse seed has a very significant effect on the rheological properties of the present emulsion, e.g. in that it provides an elastic modulus G', measured at 20°C, within the range of 100-3500 Pa, most preferably in the range of 800-2000 Pa.

The viscosity of the present emulsion typically lies in the range of 100-80,000 mPa.s, more preferably in the range of 200-30,000 mPa.s at 10 s ^"1 and 20°C. Examples of edible oil-in-water emulsions according to the present invention include dressings, mayonnaise, soups, sauces and drinks. Preferably, the present emulsion is a dressing or a mayonnaise. Most preferably, the emulsion is a mayonnaise. The emulsions according to the present invention typically are pourable or spoonable as opposed to solid. In case the present emulsion is non-pourable, it is preferred that the consistency of the emulsion is such that it cannot be cut in two as the parts of the emulsion that have been divided by the cutting will confluence after the cutting. The present emulsion typically has a Stevens value at 20 °C of 35-300, more preferably of 50-250 and most preferably of 70-200. The Stevens value, expressed in grams, can be determined by using a typical mayonnaise grid in a Stevens LFRA Texture Analyzer (ex. Stevens Advanced Weighing Systems, UK) with a maximum load/measuring range of 1000 grams and by applying a penetration test of 20 mm at 1 mm/s penetration rate in a cup having a diameter of 100 mm. The mayonnaise grid comprises square openings of appr. 3x3 mm, is made up of wire with a thickness of appr. 1 mm and has a diameter of 40 mm.

The emulsion according to the present invention typically have a shelf-life of at least 4, more preferably at least 8 weeks under ambient conditions (20°C).

Another aspect of the invention relates to a process of preparing an oil-in-water emulsion as defined herein before, said process comprising combining:

• finely ground pulse seed;

• seed mucilage component containing at least 3% by weight of dry matter of

rhamnogalacturonan mucilage gum, said rhamnogalacturonan mucilage gum being a polysaccharide having a backbone composed of (1→4)-linked β-D-galacturonopyranosyl and (1→2)-linked a-L-rhamnopyranosyl residues;

• water;

• oil; and

· optionally further ingredients.

According to a particularly preferred embodiment, the finely ground pulse seed is obtained from a pulse seed selected from lentils, chickpeas, beans and combinations thereof. Even more preferably, the ground pulse seed is obtained from a pulse seed selected from lentils, chickpeas, mung beans and combinations thereof. Most preferably, the ground pulse seed is ground lentil. The seed mucilage component preferably contains at least 5%, more preferably at least 6% and most preferably at least 7.5% by weight of dry matter of the rhamnogalacturonan mucilage gum.

The seed mucilage component preferably also contains at least 5%, more preferably at least 6% and most preferably at least 7.5% by weight of dry matter of the non-pectic neutral polysaccharide described herein before. The rhamnogalacturonan mucilage gum and the non-pectic neutral polysaccharide are preferably contained in the seed mucilage component in a weight ratio of 1 :5 to 5:1 , more preferably of 3:1 to 1 :3 and most preferably of 2:1 to 1 :2.

According to another preferred embodiment, the seed mucilage component originates from a plant belonging to the family Brassicaceae. Even more preferably, the seed mucilage component is selected from mustard bran, mustard bran extract and combinations thereof. Even more preferably, the seed mucilage component is obtained from yellow mustard.

The mustard bran extract is preferably an extract obtained by extracting mustard bran with water, ethanol or a mixture thereof. Most preferably, the mustard bran extract is an aqueous extract of mustard bran. Typically, the mustard bran extract contains at least 30%, preferably at least 50% and most preferably at least 60% of the rhamnogalacturonan mucilage gum defined herein before, by weight of dry matter. It was found that a particularly stable emulsion can be produced by combining the finely ground pulse seed and water and heating the resulting combination to denature the protein before adding the oil. Thus, in accordance with a particularly preferred embodiment, prior to the addition of oil, the combination of the finely ground pulse seed and water is heated to a temperature of more than 60°C for at least 30 seconds. Preferably the heating conditions employed are sufficient to denature at least 50 wt.%, more preferably at least 70 wt. and most preferably 90 wt.% of the pulse seed protein contained therein.

The inventors have further found that it is advantageous to add the seed mucilage component before the oil is added. The seed mucilage component may be added to the finely ground pulse seed and water before or after heating. Preferably, the seed mucilage component is added after the heating. As explained herein before, the pulse flour can be used to partially or fully replace emulsifiers and/or water-structuring agents that are commonly employed in retail emulsions such as mayonnaise and dressings. Thus, the emulsion may suitably be prepared without adding a modified starch. In accordance with a particularly preferred embodiment, the present process does not comprise the addition of a water structuring agent selected from the group consisting of modified cellulose, modified starch, xanthan, agar, gelatin, carrageenan, gellan, guar gum, locust bean gum, konjac glucomannan, gum arabic, pectin, alginate, chitosan. The oil-in-water emulsion of the present invention is suitably produced by:

• providing an aqueous dispersion containing at least 0.1 wt.% of finely ground pulse seed and at least 0.01 wt.% of seed mucilage component,

• adding oil to the aqueous dispersion to produce an oil-and-water mixture; and

• mixing the oil-and-water mixture to produce an oil-in-water emulsion comprising 80-100 vol.% of oil droplets having a diameter of less than 20 μηη.

Preferably, the present process comprises the addition of an acidulant to adjust the pH of the aqueous dispersion to a pH within the range of less than 5.5, preferably to a pH of 2 to 5.5, more preferably to a pH of 3.0 to 5.0. According to a particularly preferred embodiment, the acidulant is added, after the oil has been added to the aqueous dispersion, even more preferably after the oil-in-water emulsion has been produced by the mixing.

As explained herein before, gelatinization of the starch provided by the pulse seed components enhances the water-structuring properties of said component. The starch provided by the pulse seed component may suitably be gelatinized by heating the aqueous dispersion containing finely ground pulse seed to a temperature in excess of 60°C for a sufficiently long period of time. It is also possible to prepare the aqueous dispersion of finely ground pulse seed from a pulse flour that has been pretreated to gelatinize the starch. Preferably, the presence process comprises the step of heating the aqueous dispersion containing the finely ground pulse seed to gelatinize the starch contained therein. Depending on the heating temperature, the preferred times are as follows:

60-70°C: 10-120 minutes

70-80°C: 1 -80 minutes

80-100°C 1 -70 minutes

100-120°C: 30-1200 seconds 120-150°C: 10-480 seconds

According to a particularly preferred embodiment 50-100 wt.%, more preferably 70-100 wt.% of the starch comprised in the aqueous dispersion is gelatinized prior to the addition of the oil.

The pulse flour that is mixed with water to prepare the aqueous dispersion preferably has the same composition as described herein before in relation to the pulse seed that is contained in the edible oil-in-water emulsion of the present invention.

In the present process the aqueous dispersion is suitably prepared by mixing pulse flour with water and optionally further ingredients. Preferably, the pulse flour employed has a mass weighted average particle size of 10-500 μηη, more preferably of 15-120 μηη, and containing more than 90 wt.% of particles, preferably more than 95 wt.% of particles having a diameter of 150 μηη or less. The particle size distribution of the pulse flour is suitably determined with the help of sieves.

The invention is further illustrated by means of the following non-limiting examples. EXAMPLES

Example 1

Mayonnaise having an oil content of 50 wt% was prepared on the basis of the formulation described in Table 1.

Table 1

* Finely ground yellow mustard bran (product code 412, G.S. Dunn Limited, Ontario, Canada) ^** Adjust to pH 3.6-3.8

The procedure used to produce the mayonnaise was as follows:

• disperse mustard bran into water and heat at 80 °C for at least 30 min

· mill the lentils in a grinder to produce flour having a mass weighted average particle size of approximately 40 μηη and less than 1 wt% particles larger than 120 μηη

• mix the lentil flour into the mustard bran dispersion

• heat the mixture to 95 °C and maintain at 90-95 °C for 5 min.

• cool mixture to 30-40 °C

· add sugar and salt

• add oil slowly with Silverson mixer at about 7000 rpm

• adjust pH with vinegar during last stage of mixing

• add egg yolk and homogenise using a Silverson mixer operated at low mixing speed (1000 rpm) for 1 min.

A control sample without mustard bran (replaced by water) was prepared in the same way (lentil flour is dispersed in water in this case). After preparation samples were stored at 5 °C and syneresis (water release) was measured at different times. The method for measuring syneresis was as follows:

• 200 ml glass jars were filled with 170 gram mayonnaise

• perspex tubes (inner diameter = 2cm, outer diameter = 2.5 cm, length = 4.5 cm) closed at one end by a piece of black ribbon filter paper (Whatman, Dassel, Germany) were inserted vertically into the mayonnaise (filter paper at the bottom) · water released into the tubes was collected at regular times using a pipette and its weight was determined

• water was put back into the tubes

The results of the syneresis measurements are shown in Table 2

Table 2

Example 2 _

A mayonnaise was prepared on pilot plant scale on the basis of the recipe shown in Table 3.

Table 3

^* Finely ground yellow mustard bran (product code 412, G.S. Dunn Limited, Ontario, Canada)

^** Adjust to pH 3.6-3.8

^*** Heat stabilized egg yolk, modified with Maxapal™ A2 (Bouwhuis Enthoven B.V.,

Netherlands)

The procedure used to produce the mayonnaise was as follows:

• disperse mustard bran in cold water and heat to 85 °C; maintain temperature at 85 °C for 5 min

· disperse lentil flour in cold water and heat to 85 °C; maintain temperature at 85 ° for 5 min

• combine mustard bran and lentil flour dispersions; cool mixture to 30-40 °C

• add sugar and salt

• add oil (in 1 min) to Fryma Del mixer while milling at 3000 rpm

· continue milling at 3000 rpm for 1 min after all oil is added

• add acids (in 30 sec) while milling at 3000 rpm

• add modified egg yolk (in 30 sec) while milling at 3000 rpm

A control sample was prepared in which the mustard bran was replaced by water.

Syneresis, oil droplet size and Stevens values were determined for the both the mustard bran containing sample and the control. The results are shown in Table 4.

Table 4

Syneresis after D ₃ ,2 (μπη) Stevens (g)

1 wk

0.25 wt.% mustard bran 1 .9 g 5.0 129

Control 3.6 g 6.5 88 Example 3:

Mayonnaise having an oil content of 50 wt% was prepared on the basis of the formulation described in Table 1 , except that mustard bran was replaced by soluble mustard mucilage fraction and egg yolk was replaced by modified egg yolk.

Preparation of a soluble mustard bran mucilage fraction was as follows:

• disperse mustard bran in cold water at a concentration of 40 g/kg

· heat to 90 °C and maintain temperature at 90 °C for 2 hours while stirring (magnetic stirrer, 700 rpm)

• cool down to room temperature and centrifuge at 6000 xg (Beckman Avanti J-25 centrifuge)

• after centrifugation separate supernatant phase (dissolved mucilage) from sediment phase (non-dissolved mustard bran material)

Preparation of the mayonnaise was as follows:

• disperse lentil flour in cold water and heat to 95 °C; maintain temperature at 90-95 °C for 5 min

• cool lentil dispersion to 30-40 °C

• add soluble mustard bran mucilage to lentil dispersion

• add sugar and salt

• add oil slowly with Silverson mixer at about 7000 rpm

· adjust pH with vinegar during last stage of mixing

• add egg yolk and homogenise using a Silverson mixer operated at low mixing speed (1000 rpm) for 1 min

A control sample was prepared in which the water soluble mustard bran mucilage was replaced by water.

Syneresis was measured following the procedure described in Example 1 . In addition, G' was measured at 20°C using procedure described herein before. The results of the syneresis measurements are shown in Table 5.

Table 5 after 3 wks 6.33 g 7.75 g

The results of the G' measurement are shown in Table 6 Table 6

soluble mucilage control

G'at 20°C 644 Pa 843 Pa