The present invention relates to a food composition and a process for its preparation. There is a general desire in food industries, and particularly the confectionery industry, to enable consumers to address the health problems associated with high-calories, and particularly high-fat diets. This desire has led to the introduction of a number of food products in which the calorific content and/or fat content has been reduced. Typically, these food products involve the replacement of sugars with low-calorie sweeteners, and/or the replacement of fats with non-fats.

Colloidal systems have been employed to modify the properties of chocolate. US4446166 describes a method for the preparation of a heat-resistant chocolate by dispersing 2-10wt% of a water-in-fat emulsion (a colloidal system) through a conventional chocolate whilst it is in the liquid state. WO2009/090416 describes a comestible product comprising a water-in-oil system where a fat-crystal stabilised aqueous phase is dispersed through a cocoa butter continuous phase.

A colloidal system can be defined as a system comprised of two immiscible phases, one of which is dispersed as droplets (the discrete, internal, or discontinuous phase) throughout the other (the bulk, external or continuous phase).

Colloidal systems are unstable by definition since the free energy of the system is higher than the free energy of the phases separately. For this reason, they are prone to destabiliation processes such as coalescence, Ostwald ripening, flocculation, creaming and sedimentation. This lack of stability can be disadvantageous during processing, especially if warm conditions are required. The lack of stability also impacts on shelf life e.g. a chocolate prepared using a water-in-oil emulsion may suffer from "grits" over time (where sugar dissolves in the water providing an unpleasant sensation).

It is an object of the present invention to provide a colloidal system with greater stability. It is an object of the present invention to provide food compositions having improved properties such as reduced calories and/or fat.

In particular, it is an object of the present invention to provide a food composition comprising a colloidal system of improved stability.

In accordance with a first aspect of the present invention there is provided a food composition comprising either

a continuous fat phase having a dispersed aqueous phase therein; or

a continuous aqueous phase having a dispersed fat phase therein;

characterised in that the composition comprises particles selected from one or more of silica, magnesium aluminium silicate, aluminium silicate, hydrous sodium lithium magnesium silicate, sodium magnesium fluorosilicate, and titanium dioxide. It will be understood that the continuous phase having a dispersed phase therein is a colloidal system. Without being bound by theory, the particles are thought to stabilize the system by adsorbing onto the interface between the two phases (Pickering stabilisation). The particles remain solid in the system: they are insoluble in the fat and aqueous phases.

The factors involved are complex but the listed particles are considered to have the requisite size, shape and hydrophobicity to enable them to function as Pickering stabilizers. The use of solid particles is often expected to destabilize food systems such as emulsions, rather than to improve stability. WO2007/025756 describes a fat continuous network having water droplets dispersed therein and explains that the aqueous phase droplets must be gelled before the addition of particles, otherwise the emulsion may break.

In one series of embodiments the particles have a diameter (d90) of less than 30, 20, 10, 5, 3, 2 or 1 μηι (=1000nm). In one series of embodiments the particles have a diameter (d90) of at least 100, 300, 500, 700 or 900nm. In a particular embodiment the particles have a diameter (d90) of from 100 to 1000nm. By d90 we mean that 90% of the particles have diameters below this value. The use of small particles is believed to stabilize the formation of small droplets in the dispersed phase. The smaller the droplets, the less noticeable the droplets will be to the consumer. The "mouthfeel threshold" is thought to be approximately 30μηι. In one series of embodiments the dispersed phase comprises droplets having a diameter of less than 50, 40, 35 or 30μηι.

In one series of embodiments the composition comprises at least 0.6, 1.3, 2.0, 2.6, 3.2, 3.8, 4.6 or 5.3wt% particles with respect to the fat phase or with respect to the aqueous phase. In one series of embodiments the composition comprises less than 10, 8, 6, 4, 3, 2 or 1wt% with respect to the fat phase or with respect to the aqueous phase.

In one series of embodiments the composition comprises at least 0.01 , 0.05, 0.1 , 0.2, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5 or 5wt% particles (with respect to the total weight of the composition). In one series of embodiments the composition comprises less than 5, 4, 3, 2, 1 , 0.5, 0.2, 0.1 , 0.05, 0.02, or 0.01wt% particles. In one embodiment the composition comprises from 0.1 to 3wt% particles.

In one embodiment the composition comprises silica particles. Silica (Si0 ₂ ) particles include fused quartz, crystal silica, fumed silica (CAS number 112945-52-5, also known as pyrogenic silica), precipitated silica, colloidal silica, silica gel, and aerogel. In one embodiment the silica particles are fumed silica and/or precipitated silica. In one embodiment the composition comprises fumed silica (not to be confused with silica fume, CAS number 69012-64-2).

Fumed silica is produced by flame hydrolysis. It is an aggregate (100-1000nm) of fused primary silica nanoparticles (5-30nm). Originally, fumed silica particles possess surface silanol groups (SiOH), which confer a hydrophilic character. These groups can be converted to more hydrophobic groups by reaction with silane agents (such as dichloromethylsilane), which introduces hydrophobic silane groups e.g. Si-CH ₃ . Consequently, the hydrophobicity of the fumed silica particles can be tuned and quantified in terms of the residual OH content, which varies from 100% (hydrophilic) to about 20% (most hydrophobic particles). In one embodiment the fumed silica has a residual OH content of 100%. i.e. the fumed silica has not undergone any treatment to increase its hydrophobicity.

In an alternative embodiment the fumed silica has undergone treatment to increase its hydrophobicity. In one such embodiment the fumed silica has a residual OH content of less than 95, 90, 85, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30 or 25%. In one embodiment the fumed silica has a residual OH content of at least 20, 30, 40, 50, 60, 70, 80 or 90%. In a particular embodiment the fumed silica has a residual OH content from 40 to 60%. This intermediate hydrophobicity is shown to be beneficial for stabilizing oil and water colloidal systems.

In one embodiment the composition comprises magnesium aluminium silicate and/ or aluminium silicate. Suitable magnesium aluminium silicates include attapulgite (CAS12174-11-7) and hectorite (CAS 12173-47-6). Suitable aluminium silicates include kaolin (CAS 1332-58-7).

In one embodiment the composition comprises hydrous sodium lithium magnesium silicate or sodium magnesium fluorosilicate. The compounds are sold under the trade name Laponite® by Rockwood additives.

In one embodiment the composition comprises titanium dioxide (Ti0 ₂ ). Ti0 ₂ particle size is typically of the range of 100nm.

In one embodiment the continuous phase is a fat phase and the dispersed phase is an aqueous phase.

In one embodiment the continuous phase is an aqueous phase and the dispersed phase is a fat phase. In one embodiment the composition is a water-in-oil emulsion or comprises a water-in- oil emulsion; the emulsion comprises a continuous fat phase having a discontinuous aqueous phase dispersed therein.

In one embodiment the continuous phase and the dispersed phase are liquid at standard ambient temperature and pressure (SATP, 25°C, 100kPa) such that the system is an emulsion. However, the present invention extends to systems where the dispersed phase and/or the continuous phase are solid at SATP. For example, an emulsion can be prepared using molten cocoa butter (above ambient temperature). The molten cocoa butter can then be solidified at room temperature. In one embodiment the fat phase is solid at SATP.

In one embodiment the composition is an oil-in-water emulsion or comprises an oil-in- water emulsion; the emulsion comprises a continuous aqueous phase having a discontinuous fat phase dispersed therein.

The fat phase comprises an edible food-grade fat or oil. In one embodiment the fat phase comprises one or more of soya oil, cottonseed oil, peanut oil, rapeseed oil, corn (maize) oil, palm oil, safflower oil, illipe, Borneo tallow, tengkawang, sal, shea, kokum gurgi, mango kernel, sunflower oil, olive oil and cocoa butter.

In one embodiment the fat phase comprises one or more of sunflower oil, olive oil and cocoa butter. In one embodiment the fat phase comprises one or more of soya oil, cottonseed oil, peanut oil, rapeseed oil, corn (maize) oil, safflower oil, illipe, Borneo tallow, tengkawang, sal, shea, kokum gurgi and mango kernel.

In one embodiment the fat phase does not comprise one or more of sunflower oil, olive oil and cocoa butter.

In some embodiments, the fat phase comprises a tempering fat. Examples of tempering fats include cocoa butter and cocoa butter equivalents. Typically, cocoa butter equivalents are blends of vegetable fats such as palm oil mid-fraction, illipe butter, shea stearine and cocoa butter. Sal, mango, and/or kolum fats may also be used. One example of a cocoa butter equivalent is COBERINE (TM), available from Loders Croklaan B.V., Wormerveer, The Netherlands.

In some embodiments, the fat phase comprises a non-tempering fat. Examples of non- tempering fats include palm oil, palm kernel oil, butterfat, cocoa butter replacers and cocoa butter substitutes. Typically, cocoa butter replacers are hydrogenated, fractionated fat blends from soybean oil, rapeseed oil, palm oil, cottonseed oil, and/or sunflower oil, or other similar fats. Typically, cocoa butter substitutes are high lauric acid-containing fats, such as hydrogenated, fractionated fat blends from coconut and/or palm kernel oil, or other similar fats.

In a particular embodiment, the fat phase comprises cocoa butter (which can exist in at least six different crystal forms), and in particular (solid) cocoa butter in the crystal Form V (also known as β2).

In one series of embodiments the fat phase constitutes at least 1 , 2, 5, 10, 20, 30, 40, 50, 60, 70, 80 or 90wt% of the composition. In one series of embodiments the fat phase constitutes less than 90, 80, 70, 60, 50, 40, 30, 20, 15, 10, 5, 3 or 1wt% of the composition. In one embodiment the fat phase constitutes from 50 to 75wt% of the composition.

The aqueous phase comprises water. In one embodiment the aqueous phase consists of water (and therefore has a pH of 7). In alternative embodiments the aqueous phase is an acidic or alkaline solution.

In one embodiment the aqueous phase has a pH of less than 7, 6, 5, 4 or 3. In one embodiment the aqueous phase has a pH of at least 1 , 2, 3, 4 or 5. In a particular embodiment the aqueous phase has a pH of from 3 to 4. A reduction in pH is particularly beneficial when the aqueous phase comprises components which have improved solubility at acid pH. A pH of from 3 to 4 is shown to be useful when employing chitosan in the aqueous phase. In one embodiment the aqueous phase comprises one or more of acetic acid, L- ascorbic acid (vitamin C), tartaric acid, malic acid and combinations thereof.

In one embodiment the aqueous phase comprises an acidic beverage (an aqueous solution) such as a fruit juice and/or a soft drink. Suitable fruit juices include orange juice, cranberry juice, lemon juice, apple juice, apricot nectar, pineapple juice, and lime juice. Suitable soft drinks include cola, ginger beer and lemonade. The soft drinks may be carbonated if an aerated composition is desired. Alternatively the soft drink may be still. In one embodiment, the aqueous phase comprises a bulk sweetener. Examples of bulk sweeteners include sugars and sugar-free bulk sweeteners. In some embodiments, the bulk sweetener may comprise glucose syrup. Examples of glucose syrup include glucose syrup 63DE, corn syrup, high fructose corn syrup (HFCS) and mixtures thereof. Sugar-free bulk sweeteners include polyols such as xylitol, maltitol, erythritol, mannitol, sorbitol and isomalt.

In one series of embodiments the aqueous phase constitutes at least 1 , 3, 5, 7, 10, 15, 20, 30, 40, 50, 60, 70, 80 or 90wt% of the composition. In one series of embodiments the aqueous phase constitutes less than 90, 80, 70, 60, 50, 40, 30, 20, 15, 10, 5, 3 or 1wt% of the composition. In one embodiment the aqueous fat phase constitutes from 25 to 50wt% of the composition.

In one series of embodiments the ratio of fat phase to aqueous phase is from 10:90 to 90: 10, from 20:80 to 80:20, from 30:70 to 70:30, from 60:40 to 40:60 or approximately 50:50.

In one embodiment the aqueous phase (and hence the composition) comprises a chitin derivative. In one such embodiment the chitin derivative is chitosan. Without being bound by theory, the chitin derivative is thought to act as scaffolding for Pickering stabilised droplets of the dispersed phase.

Chitosan is a linear polysaccharide composed of (1→4)-linked 2-acetamido-2-deoxy- βD-glucopyraose and 2-amino-2-deoxy^D-glucopyranose. Chitosan is derived by the partial acetylation of chitin. Chitosan salts are soluble in neutral and acidic aqueous solutions, the solubility being closely related to the degree of acetylation and the aqueous phase pH.

In one series of embodiments the aqueous phase (or the composition) additionally comprises at least 0.1 , 0.3, 0.5, 0.7, 0.9, 1.0, 1.1 , 1.3, 1.5, 1.7, 1.9 or 2wt% chitin derivative. In another series of embodiments the aqueous phase (or the composition) additionally comprises less than 4, 3, 2, 1.5, 1 , 0.8, 0.6, 0.4 or 0.2wt% chitin derivative. In a particular embodiment the aqueous phase (or the composition) additionally comprises from 0.1 to 0.6wt% chitin derivative. In accordance with a second aspect of the present invention there is provided a food composition having a fat content of at least 25wt%, characterised in that the composition comprises particles having a particle size of from 100 to l OOOnm. Suitable particles include those described above in relation to the first aspect, namely silica, magnesium aluminium silicate, aluminium silicate, hydrous sodium lithium magnesium silicate, sodium magnesium fluorosilicate, and titanium dioxide.

In one series of embodiments the composition comprises at least 0.01 , 0.03, 0.05, 0.1 , 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1wt% particles having a particle size of from 100 to 1000nm.

In one series of embodiments the composition (of the first and/or second aspects) has a fat content of at least 26, 28, 30, 32, 34, 36, 38, 40, 45, 50, 55 or 60wt%. In one series of embodiments the composition has a fat content of less than 70, 65, 60, 55, 50, 45, 40 or 35wt%.

In one embodiment the composition (of the first and/or second aspect) is a confectionery composition. In a particular embodiment the confectionery composition is a chocolate composition. In alternative embodiments the confectionery composition is a chewing gum composition or a candy composition. Candy compositions include hard candies and soft candies.

In one embodiment the composition is a chocolate composition and the particles are fumed silica. In one such embodiment the composition comprises chitosan.

A suitable chocolate composition comprises cocoa liquor, cocoa butter, sweetener and emulsifier (e.g. lecithin). A suitable milk chocolate composition comprises from 10 to 14wt% cocoa liquor, from 17 to 20wt% cocoa butter, from 22 to 24wt% milk powder, from 40 to 50wt% sweetener (such as sucrose), and from 0.3 to 0.7wt% emulsifier.

A suitable dark chocolate composition comprises from 40 to 50wt% cocoa liquor, from 5 to 10wt% cocoa butter, from 45 to 50wt% sweetener and 0.3 to 0.7wt% emulsifier. The invention also resides in food products incorporating the food compositions of the first and second aspects, e.g. a food product having the composition as a filling or as a coating.

In accordance with a third aspect of the present invention there is provided a method for the preparation of the composition of the first aspect comprising

separately providing a fat phase and an aqueous phase;

mixing particles with either the fat phase or with the aqueous phase;

combining the fat phase and the aqueous phase and agitating to provide either a continuous fat phase having a dispersed aqueous phase therein; or

a continuous aqueous phase having a dispersed fat phase therein;

characterised in that the particles are selected from one or more of silica, magnesium aluminium silicate, aluminium silicate, hydrous sodium lithium magnesium silicate, sodium magnesium fluorosilicate, and titanium dioxide.

Without being bound by theory, the inventors believe that the continuous phase will usually be the phase which shows the highest affinity/wettability for the particles, e.g. the fat phase tends to be continuous for hydrophobic particles such as hydrophobic fumed silica.

The fat phase, aqueous phase and particles are as described above.

In one embodiment the fat phase and the aqueous phase are combined by adding the fat phase to the aqueous phase. Such a process encourages the formation of a continuous aqueous phase having a dispersed fat phase therein.

In one embodiment the fat phase and the aqueous phase are combined by adding the aqueous phase to the fat phase. Such a process encourages the formation of a continuous fat phase having a dispersed aqueous phase therein.

In one embodiment the particles are mixed with the fat phase before the fat phase and the aqueous phase are combined. In one such embodiment, where the particles have intermediate hydrophobicity (e.g. fumed silica having 50% residual OH), the resulting composition is expected to have a continuous fat phase. In one embodiment agitating is shaking the fat phase and the aqueous phase. In one embodiment agitating is shearing with a rotor-stator mechanical shearer. In one series of embodiments agitating takes place for at least 30, 60, 90, 120, 150, 180 or 210 seconds. In one series of embodiments agitating takes places for less than 300, 240, 180, 150, 120, 90, 60 or 30 seconds.

In one embodiment the process is carried out at from 10 to 30°C or from 15 to 25°C. This is useful if the fat phase comprises fats that are liquid at SATP. In another embodiment the process is carried out at 30 to 50°C or from 35 to 45°C. This is useful for cocoa butter and other fats that have a melting point above SATP.

Hence it will be understood that there are several methods for obtaining a chocolate composition using the invention. The compositions of the first and second aspects can be employed to replace the cocoa butter (or a portion thereof) in a standard process for the preparation of chocolate. A chocolate composition could be prepared using conventional methods, and then the fat/aqueous system added thereto to reduce the fat content. Or the chocolate ingredients (sugar, milk powder etc) could be added to the aqueous phase or to the fat phase before they are combined so that the resulting composition is a chocolate.

Embodiments of the present invention will now be described by way of example with reference to the following figure.

Fig 1 is a schematic diagram showing the effect of silica concentration on the volume of emulsion.

METHODOLOGY

Particles (Fumed silica particles from Wacker Chemie)

SiOH content Character

HDK N20 100% Hydrophilic

HDK H20 50% Intermediate

HDK H18 20% Hydrophobic Fat phase

Dark chocolate (28.8% fat)

Milk chocolate (32.8% fat)

White chocolate (33.5% fat)

Aqueous phase

Cranberry juice (Ocean Spray RTM)

Cola (Pepsi RTM)

Smooth orange juice (Tropicana RTM)

Low and medium molecular weight chitosan 75-85% deacetylated (Sigma Aldrich Corp) Glacial acetic acid (Sigma Aldrich Corp)

L-ascorbic acid (Sigma Aldrich Corp)

CONTROL 1 - sunflower oil as fat phase (no particles)

A series of emulsions were prepared using chitosan as the sole stabiliser. 1wt% of chitosan was dissolved in water in the presence of an excess of acetic acid to give a solution having a pH of 3.2. The aqueous solution was then mixed with sunflower oil in a 1 :1 ratio and subsequently emulsified using low shear (e.g. handshaking for 30s). Very low volume W/O emulsions were obtained i.e. there were significant fractions of separate aqueous and fat phases. Upon storage these emulsions ripened and destabilized within several days. The lack of stability is believed to be due to chitosan being only a moderately efficient emulsifier, possibly due to its stiff polysaccharide nature.

SYSTEM 1 - Olive oil/sunflower oil as fat phase

From 0.045g to 0.400g of fumed silica particles were weighed in a sample bottle (corresponding to from 0.6 to 5.3% by weight, based on the aqueous phase). 7.5g of oil (olive oil/sunflower oil) was subsequently added and the whole was gently mixed. 7.5g of water phase (de-ionized water; 1wt% acetic acid aqueous solution; or 1wt% chitosan, 1wt% acetic acid solution) was added and the sample bottle was shaken (either 30s by hand or 2 minutes using a rotor-stator mechanical shearer (ultra-turrax 1 1000 rpm)). The samples were allowed to stand and analysed one day later. The fat and aqueous phases separated with the less dense fat phase (oil phase = O) toward the top and the denser aqueous phase (water phase = W) at the bottom of the sample bottle. An emulsion (E) of varying volumes formed between the fat and aqueous phases. The heights of the fat phase, the aqueous phase and the emulsion were measured one day after shaking as an indication of the volume of the emulsion.

Figure 1 is provided as an example. It shows H18 silica particles (hydrophobic) in 1 :1 water: oil ratios for both olive oil and sunflower oil. The volume of the emulsion increases with the amount of silica particles from 0.2-0.4 at 0.7wt% to 2.1 at 5.3wt%. For all systems tested (olive or sunflower oil, 1 :1 and 1 :3 ratios) the emulsion volume tends to increase upon increase of the silica particle concentration.

Limited coalescence was observed upon storage by the appearance of larger droplets for the emulsions prepared with either the hydrophilic (HDK N20) or the hydrophobic (HDK H18) fumed silica. The cause might be weaker adsorption of the silica particles at the oil-water interface. On the contrary, the W/O emulsions prepared with the HDK H20 (intermediately wettability) were stable to coalescence. HDK H20 was therefore chosen for further study. The emulsions were stable for weeks indicating that the silica particles stabilise the emulsion.

The hydrophilic silica particles (N20) were found to stabilize oil-in-water emulsions whereas more hydrophobic silica particles (H20 and H18) stabilize water-in-oil emulsions.

The size of the droplets in the emulsion could be controlled by means of the energy supplied. The more energy supplied the smaller the droplet diameter (until a critical droplet size). As an example, emulsions prepared by hand with a 1 : 1 sunflower oil emulsion comprising chitosan and 2wt% H20 silica particles had droplets with a broad size distribution and a size of the order of 100μηι (for low silica concentrations). This is approximately one order of magnitude larger than the equivalent created with 2 minutes of high shear emulsification (Ultraturrax). The size of the droplets also depends on the silica concentration. When all the silica particles are completely and irreversibly adsorbed, the average droplet diameter is inversely proportional to the amount of silica. The droplet diameter decreases from about a few tens of μηι to about 10μηι from 0.7 to 5.3wt% silica. By plotting the mean droplet diameter as a function of the silica particle concentration, we infer that the fumed silica particles do not adsorb onto the surface of the emulsion droplets as an array of densely packed primary particles, but rather adsorb as large aggregates. The silica aggregates are thought to be connected to the droplet surface by a number of anchoring particles, the other particles protruding toward the continuous phase. The use of 1wt% chitosan: 1wt% acetic acid solution (pH 3.2) instead of water resulted in the entire aqueous phase being dispersed in all cases. The composition comprising 5.3% silica did not flow under its own weight. The inventors propose that the origin is a continuous network of colloidal floes, which effectively renders the emulsion into a quiescent state, that is the aqueous droplets are dispersed into a solid-like matrix, thereby cancelling out settling.

The table below shows the viscosities measured using a single shear Brookfield DV-II, spindle number 63 at 20rpm of prepared 1 : 1 water:sunflower oil emulsions at a constant HDK H20 silica particle loading of 2wt% with respect to the oil phase, and different chitosan concentrations. The viscosity increases from 690mPas to approximately 2000mPas when the chitosan concentration increases from 0 to 1wt%. At higher chitosan concentrations the values plateau at 2200-2300mPas. We consider the viscosity increase to be directly related to the increase of the oil-water interface due to improvement of wetting properties of the silica particles by chitosan adsorption onto their surface.

Chitosan concentration (wt%) Viscosity (mPa s)

0 690

0.2 1000

0.5 1700

1.0 2050

2.0 2200

3.0 2300 SYSTEM 2 - Cocoa butter as fat phase

Experiments were carried out employing cocoa butter as the fat phase and water, orange juice and cola as the aqueous phase. The samples were prepared as described above except the cocoa butter and aqueous phase were heated to 40°C to ensure the cocoa butter was liquid. In order to obtain droplets of diameter below 30 micron (mouthfeel threshold), an ultraturrax was employed at l OOOOrpm for 120s.

The products were analysed by freeze-fractured cryogenic scanning electron micrograph. The mean average droplet diameter is 11.76μηι. Upon closer inspection of the individual droplets, the fumed silica floes were clearly visible at the interface of the droplet confirming their role as a Pickering stabilizer. Silica floes were not present within the water droplets.

The presence of 1wt% chitosan in the water phase of 1 : 1 cocoa butter: water phase emulsions with 2wt% silica particles (especially the H20 grade) was beneficial toward the preparation of fat continuous compositions. These compositions had a dispersed aqueous phase of small and homogenously spread droplets within a cocoa butter matrix. This conclusion could be drawn for the compositions prepared with water, orange juice and cola as the aqueous phase. On the contrary, samples prepared with a solution containing 40wt% ethanol separated, regardless of the presence of chitosan.

Chocolate Formulations

Chitosan was added to smooth orange juice, cranberry juice or decarbonated cola at 40°C. L-ascorbic acid was used to lower the pH to dissolve the chitosan and thereby provide an aqueous phase having a pH of 3.2-3.8. The chocolate (dark, milk and white) was heated to 40°C to melt it and fumed silica was dispersed therein. The melted chocolate and aqueous phase were then mixed and emulsified using a rotor stator mixer for 60s. An equal ratio of aqueous phase with respect to the fat content of the chocolate was used. i.e. 28.8g aqueous phase was added to 100g dark chocolate.

Immediately after, formulations were cooled to 28°C (dark chocolate) or 26°C (milk and white chocolate) prior to gradual reheating whilst stirring to 33°C (dark chocolate) or 31.6°C (milk and white chocolate) and holding at that temperature for 5 minutes (a tempering procedure). Samples were then refrigerated for 2 weeks before Differential Scanning Calorimetry (DSC) analysis.

Stable products were obtained with when at least 2wt% fumed silica was employed (with respect to the aqueous phase). This corresponds to approximately 0.4-0.5wt% silica fume based on the total chocolate composition.

The DSC analysis showed that a large fraction of the product has cocoa butter in its polymorph V crystalline structure. This is the desired form which gives chocolate a desirable texture and hinders fat and sugar bloom.