MILK CHOCOLATE CONTAINING WATER

Abstract: A process for manufacturing milk chocolate containing a higher than normal water content which comprises preparing a dark chocolate containing up to 30 % by weight of water, adding a milk powder suspension optionally together with seed crystals of cocoa butter or cocoa butter equivalent, and mixing under low shear.

Description: MILK CHOCOLATE CONTAINING WATER FIELD OF THE INVENTION The present invention relates to milk chocolate containing water and more particularly to a process for manufacturing milk chocolate containing a higher than normal water content. BACKGROUND OF THE INVENTION Conventional chocolate production and processing methods avoid contact with water since small amounts of added water cause severe rheological changes in the product, usually accompanied by lumping and/or granulation leading to a coarse unacceptable eating texture (Minifle, B. W. Chocolate, Cocoa and Confectionery - Science and Technology, 3 edition, Chapman & Hall (1989)). On the contrary, addition of larger quantities of water, usually in the form of fresh cream or full cream milk, results in the production of "ganache" which is conventionally used as a short shelf-life filling for truffles or as a topping for confections. Ganache is the confectioner's term for a phase-inverted (i.e. oil-in-water) chocolate preparation and has a softer eating texture than normal chocolate and does not have the snap of traditional chocolate when broken. EP-A-832567 describes a process for the preparation of chocolate or the like with a high water content in which water is in a dispersed phase in the form of micro- droplets in a continuous fatty phase, itself containing crystallised sugars, characterised in that a mass of chocolate is carefully mixed into an emulsified water-in-oil base, so that destruction of the water-in-oil structure of the emulsion is substantially avoided as well as contact between the sweetened components and the non- fatty solids of cocoa on the one hand and the dispersed aqueous phase on the other, this contact being responsible for the formation of agglomerates and in that the ability of the chocolate to be converted by the conventional manufacturing process is maintained. However, we have found that when a milk chocolate with a high water content is produced by this process, a ganache is obtained whose softer texture and poor contraction makes it unsuitable for conventional chocolate manufacturing processes such as moulding, where the product does not contract so that it will not come out of the mould. EP-A-958747 overcomes the above problem by adding a sucrose syrup and claims a method for the preparation of a water-in-oil phase chocolate formulation, the method comprising the step of admixing a concentrated sugar syrup to a chocolate fat phase with a fat content of at least 25 % w/w under conditions of low shear at a temperature of from 30°C to 55°C wherein the viscosity of the sugar syrup is in the range of from 500 cps to 140,000cps measured at 20°C and the sugar syrup has a solids content of at least 70% w/w and wherein the final moisture content of the chocolate formulation is in the range of from 2% to 20% w/w and the fat content usually ranges from 28% to about 45%w/w. This process, however, only works if there is no crystallisation of sugar in the sugar syrup phase of the formulation during preparation. Also this sugar syrup is added to the chocolate fat phase not to the chocolate itself. This means, in the case of dark chocolate, the sugar is added as the syrup to a mixture of cocoa butter and cocoa liquor i.e. not chocolate. In traditional chocolate making, a conching process is used to obtain the correct flavour in the final product (Beckett, S.T. Industrial Chocolate Manufacture and Use, 3 rd Edition, Chapter 9, Blackwell Science, 1999). This process could not be used in this case, as the need for a slow speed mixer is emphasised, whereas a conche is a higher shear device. Our research has noted that the application of higher speed mixing to all types of water containing chocolate results in a ganache type of product. This dark chocolate therefore can not be conched and have the taste of a fully processed dark chocolate. In contrast, the present invention, however, includes the possibility of adding water to a traditionally produced dark chocolate. In the preparation of milk chocolate EP-A- 958 747 adds the syrup to milk chocolate ingredients, but with a lower sugar content. If a normal sugar content were present (usually above 45% - Beckett, S.T. Industrial Chocolate Manufacture and Use, 3 rd Edition, Chapter 18, Blackwell Science, 1999) the addition of further sugar through the syrup would result in a product with other sugar content outside the recognised legislative limits for chocolate (Beckett, S.T. Industrial Chocolate Manufacture and Use, 3 rd Edition, Chapter 23, Blackwell Science, 1999). In addition, if sucrose or glucose like sugars were used in the syrup the product would be extra sweet. Also this illustrates that once again the syrup is being added to unconched ingredients. The levels of sugar used in the examples of EP-A-958747 given are in fact more typical of those used in ice-cream chocolate and the patent states that the eating texture is very complementary with ice-cream chocolate. Ice-cream coatings, however, have a different texture to traditional chocolate tablets (Beckett, S.T. The Science of Chocolate, Royal Society Of Chemistry, 2000). Without excluding its use in ice-cream, the chocolate of the current invention has a texture similar to a traditional tablet chocolate at ambient temperatures. In developing the current invention it was discovered that the presence of non-fat milk solids destabilised water containing milk solids when their level approached that which is required by legislation (Beckett, S.T. Industrial Chocolate Manufacture and Use, 3 rd Edition, Chapter 23, Blackwell Science, 1999) but milk solids are also required to give the milk chocolate its traditional taste and texture. It should be noted that the milk solids levels quoted in the example of EP-A-958747 are below this level and that the water contents are lower than for the dark chocolate. The current invention works optimally at higher moisture levels, e.g. about 10% - 15%, and can employ the required levels of milk solids. US-A-5468509 describes a milk chocolate containing 1-16% water in which the chocolate preparation is produced by mixing cocoa butter with cocoa ingredients in the presence of an edible emulsifier so that the ingredients are thoroughly coated with cocoa butter. This mixture is then blended with an aqueous phase prepared separately by mixing water, sweetener and milk solids to give a uniform mixture without resulting in high viscosity, followed by tempering at 27-32°C in the absence of a conching step. We have found that conching turns the mixture into a ganache which cannot be moulded satisfactorily because it does not contract out of the mould. As was the case with EP-A-958747, this absence of a conching stage will result in a chocolate with a different taste to a traditional chocolate (Beckett, S.T. Industrial Chocolate Manufacture and Use, 3 rd Edition, Chapter 9, Blackwell Science, 1999) EP-A-401427 describes a cream-containing chocolate which contains about 1.8 to 10% of moisture content and not less than 3% of milk fat content, the improvement in that a W/O type emulsion consisting of a cream which has not less than 30 % of milk fat content and a lipophilic emulsifier is mixed in a chocolate base material which may be a dark, milk or white chocolate, by kneading. The chocolate product can contract from a mould because the fat, which contracts when changing from liquid to solid on cooling, is the continuous phase. No (non-fat) milk solids are present in the W/O type emulsion even when a milk or white chocolate is to be prepared. This means that it can not legally be called milk chocolate, nor can it have the taste and texture of a typical milk chocolate tablet. Although not wishing to be bound by this theory, we believe that if the required amount of milk solids were present in the W/O type emulsion, the hydrophilic proteins present in milk solids would attract water and destroy the emulsion structure. Water and hydrophilic particles would then become the second continuous phase when the emulsion is mixed with the chocolate base material i.e. it would become like ganache and the chocolate product could not contract from the mould.This is because water does not significantly contract, because unlike fat it does not solidify during the cooling process. None of the above processes are completely satisfactory, e.g. they are either not cost-effective, the eating texture is not considered by the consumer to be typical of a milk chocolate bar at ambient temperatures, or the chocolate cannot be readily be removed from a mould. We have now devised a process for manufacturing milk chocolate containing a higher than normal water content which is cost-effective, the chocolate has excellent organoleptic properties and can easily be demoulded. In addition, a low fat and calorie content can be achieved. Many products are now sold to provide the consumers with added benefits to their health e.g. added vitamins or calcium. Some of these ingredients are soluble only in water or only in fat e.g. vitamin A is fat soluble and vitamin C water soluble. Water-containing chocolate can contain both water and fat soluble components in the same bar e.g. both fat-soluble and water-soluble vitamins and therefore have a more overall beneficial effect. We have found that by adding the milk solids in a slurry form to a dark chocolate already containing the water for manufacturing milk chocolate containing a higher than normal water content, the process is made more robust, in that it can tolerate a higher mixing rate than would be possible if an emulsion were added to normal milk chocolate. Attempts to add an emulsion to normal milk chocolate result in ganache unless the mixing were carried out at extremely low rates, which would make it commercially unviable and, in addition, we have found that milk chocolates made under these extremely low shear/mixing rates become white due to bloom within 24 hours. In contrast, milk chocolates produced according to our invention using a milk slurry and cocoa butter seed at the rate of several kilograms per hour have remained bloom free for up to six months or longer. As is well known, it is unnecessary to temper chocolate which is to be used for coating ice cream. However, it is customary and essential to temper chocolate which is consumed at ambient temperatures. Standard tempering machines use high shear rates, and in fact this is regarded as beneficial (Beckett, S.T. Industrial Chocolate Manufacture and Use, 3 rd edition, pages 236 - 238, Blackwell Science). However, such high shear rates would change a water containing chocolate into ganache. We have found that tempering may be achieved by an alternative method of adding seed crystals in the form of solid fat is therefore preferable as high shear rates are no longer required. The seed crystals can be in the form of cocoa butter alone, or the fat seeds may be within solid chocolate or cocoa liquor or cocoa powder pieces. SUMMARY OF THE INVENTION According to the present invention there is provided a process for manufacturing milk chocolate containing a higher than normal water content which comprises preparing a dark chocolate containing from 1 to 30% by weight of water, adding an oil or fat suspension of milk powder and mixing under low shear. When tempering of the milk chocolate is required, seed crystals of cocoa butter or cocoa butter equivalent may be added together with the oil or fat suspension of milk powder to the dark chocolate containing from 1 to 30% by weight of water. DETAILED DESCRIPTION OF THE INVENTION The milk chocolate produced by the process of the present invention may have a water content from 1.5 to 25%, preferably from 5 to 20%, more preferably from 7.5 to 17.5%), and especially from 10 to 15% by weight based on the weight of the milk chocolate. The dark chocolate containing from 1 to 30% by weight of water may be prepared by any known method. In this case the dark chocolate material (which can be a traditional conched dark chocolate or a compound containing vegetable fat, etc.) is added to a water-in-oil emulsion using light mixing. The mixing must be sufficient to disperse the water throughout, but not so strong as to form a continuous phase. The water may then be in the form of individual droplets as suggested by EP-A- 832567, or in the form of sucrose solution droplets as suggested by our investigations, or may be formed using methods such as the one described in EP- A-958747. In the case of using an emulsion, the water content of the water-in-oil emulsion may conveniently be from 10 to 80% by weight and preferably from 40 to 70% by weight. The oil in the water-in-oil emulsion may be cocoa butter or a cocoa butter substitute which is a vegetable fat capable of being used to replace cocoa butter in chocolate and couvertures and well known to those skilled in the art. The emulsifier in the water-in-oil emulsion may be, for example, lecithin, a polyglycerol ester of a fatty acid such as polyglycerol polyricinoleate (PGPR) or diacetyl tartaric acid esters of monoglycerides or any mixture of two or more emulsifiers. The size of the droplets of the emulsion is preferably below 10 microns. The amount of emulsifier may be from 0.5 to 3% by weight and preferably from 0.75 to 2% by weight based on the weight of the water-in-oil emulsion. The dark chocolate material may comprise the usual ingredients, i.e. cocoa liquor, cocoa butter and sugar together with an emulsifier, or it may be a chocolate analogue well known to those skilled in the art. It should be understood that the term chocolate is employed in this description to designate chocolate and its analogues. Thus, all or part of the cocoa butter may be replaced by a fat of vegetable origin or a mixture of fats of vegetable origin currently used in confectionery of which the physico-chemical properties are similar to or equivalent to those of cocoa butter. In addition, sugar may be replaced partially or completely by a substitute such as a low calorie sweetening agent, e.g. an alcohol such as sorbitol, mannitol, isomalt, maltitol, xylitol, erythritol and galactitol. In one example the dark chocolate material may be prepared by conventional methods including a conching step. The dark chocolate material is added in molten form to the emulsified water-in-oil base, e.g. at a temperature from 32° to 50°C, preferably from 33° to 35°C, with stirring at low speed, e.g. 50 to 150 for a shear stress from 20 to 100 Pa. for a period of from 1 to 10 minutes, preferably from 2 to 5 minutes. The emulsified water-in-oil base may be mixed with the dark chocolate material in a ratio of emulsified water-in-oil base to dark chocolate material so as to give a water content of the required percentage. This is likely to be within the range of from 1:20 to 1.1. The incorporation of the dark chocolate material into the emulsified water-in-oil base may be carried out batchwise or continuously. The dark chocolate produced by mixing the dark chocolate material with the emulsified water-in-oil base preferably contains from 2 to 25% by weight of water, more preferably from 5 to 20% by weight of water. The oil or fat suspension of anhydrous milk powder contains an emulsifier such as lecithin, a citric acid ester, diacetyl tartaric acid esters of mono-and di-glycerides (DATEM) or polyglyceryl polyricinoleate (PGPR) in an amount of from 0.1 to 1% by weight, and may be added to the dark chocolate containing from 1 to 30% water either before or together with seed crystals of cocoa butter or cocoa butter substitute and mixed under low shear, e.g. 50 to 150rpm for a shear stress from 20 to 100 Pa. When the milk powder suspension is added before the seed crystals of cocoa butter or cocoa butter substitute, the mixing may be carried out at a low rotational speed, e.g. 50 to 150rpm for a shear stress from 20 to 100 Pa. for a period of from 1 to 10 minutes, preferably from 2 to 5 minutes, at a temperature within the range from 35° to 50°C, after which time the mixture was cooled to a temperature from 30° to 34°C and the seed crystals added and the stirring continued until crystallisation occurred, e.g. for a period of from 1 to 15 minutes. When the milk powder suspension is added to the dark chocolate containing from 1 to 30% water together with seed crystals of cocoa butter or cocoa butter substitute, the mixing may be carried out in a static mixer, e.g. by pumping the mixture through the static mixer, at a temperature from 25°C to 38°C, conveniently from 30° to 34°C for cocoa butter, after which the mass may be directly moulded. Preferably the milk powder suspension may be prepared by mixing the appropriate amounts of non-fat milk solids, milk fat, and an emulsifier to provide a slurry which is added together with the seed crystals of cocoa butter or cocoa butter substitute to the water-containing conched dark chocolate. The amount of the milk powder suspension added to the dark chocolate containing from 1 to 30% water may be an amount sufficient to provide the quantity of milk solids (including milk fat) normally present in milk chocolate-like products, e.g. from 10 to 30% by weight, preferably from 15 to 25% by weight based on the total weight of the milk chocolate. If desired, the fat content of the milk powder suspension may be lowered by adding other non-fat solids, e.g. non-fat cocoa solids. Preferably these should be non-hygroscopic or should be coated with an emulsifier to reduce their hygroscopy, e.g. cocoa powder and lecithin. This is then mixed with the milk powder suspension and the dark chocolate containing from 1 to 30% water. The amount of non-fat solids, e.g. non-hygroscopic non-fat solids, added may be from 0.5% to 60%. The amount of seed crystals of cocoa butter or cocoa butter substitute may be from 1 to 20% by weight and preferably from 5 to 15% by weight based on the weight of the milk powder suspension . The milk chocolate produced by this invention has excellent eating quality and can easily be demoulded. In addition, a low fat and calorie content can be achieved because of the presence of higher than normal amounts of water. The present invention therefore also provides a milk chocolate containing higher than normal amounts of water and less than normal proportions of fat and sugar. The amount of water in the milk chocolate may be from 1.5 to 25%, preferably from 5 to 20%, more preferably from 7.5 to 17.5%, and especially from 10 to 15% by weight based on the weight of the milk chocolate. The amount of fat may be less than 27%, preferably less than 25% and especially from 24 to 20% fat by weight based on the weight of the milk chocolate. The amount of sugar may be less than 40%>, preferably less than 37.5%> and especially from 30 to 35%> sugar by weight based on the weight of the milk chocolate. Water has zero calories and is therefore a good component of low calorie food. Many of the other ingredients in common usage, e.g. sugar alcohols as sugar replacers, not only have a significant calorific contribution themselves, but also have a restricted consumption owing to their laxative effect. The milk chocolate containing higher than normal amounts of water according to the present invention may be used as a coating for ice cream in which case, since tempering is unnecessary for an ice cream coating, the addition of the seed crystals of cocoa butter or cocoa butter equivalent to the dark chocolate is unnecessary. EXAMPLES The following Examples further illustrate the present invention. Parts and percentages are indicated by weight. Example 1 40 parts water, 39 parts cocoa butter and 1 part polyglycerol polyricinoleate are mixed for 3 minutes at 33°C using a rotor-stator device rotating at 130rpm to give 80 parts of an water-in-oil emulsion having a droplet size below 10 microns. 320 parts of a dark chocolate prepared by conventional methods including a conching step is melted and added at 33°C to the water-in-oil emulsion in the anchor stirrer and stirred for a further 3 minutes to produce a dark chocolate containing 10% water. 85 parts of a fat suspension of milk powder are prepared by mixing 58 parts non- fat milk powder, 13.5 parts milk fat, 13 parts of cocoa butter and 0.5 parts lecithin is added together with 8 parts of grated dark chocolate. This milk powder suspension is added to the 400 parts of the above dark chocolate containing 10% water and stirred for 2 minutes at 130rpm at 31°C to give a milk chocolate containing 8% water and 23% fat. The milk chocolate is charged to a mould followed by cooling from which it was removed easily to provide the moulded product The milk chocolate produced has excellent eating quality and texture and, in addition to the higher than normal water content, can easily be demoulded as well as having a low fat and calorie content. It can also incorporate both fat and water soluble beneficial components. Example 2 0.3 parts of polyglycerol polyricinoleate are mixed with 9.2 parts of cocoa butter and stirred with a rotor-stator device at 100 rpm for one minute at 40°C. 13.5 parts of water at 40°C are added and the mixture is further stirred for 2 minutes. The emulsion droplets are finely dispersed by increasing the speed of the rotor-stator device to 5000 rpm for 2 minutes to give 23 parts of emulsion. 8 parts of non-fat milk powder, 2.5 parts of milk fat, 2.4 parts of cocoa butter and 0.1 parts of citric acid ester of monoglycerides are mixed at 35°C to give 13 parts of suspension. 40 parts of dark chocolate prepared by conventional methods including a conching step is melted and mixed at 32°C with 23 parts of the emulsion in a static mixer to give water-containing dark chocolate. 13 parts of the fat suspension of milk powder prepared as above and 2 parts of cocoa butter seed are continuously added to the product flowing in a pipe and mixed in a second static mixer, whereupon the water containing milk chocolate can be moulded directly. Once again the chocolate which contains 17% water was demoulded and had a hardness associated with conventional chocolate.

Claims: CLAIMS 1. A process for manufacturing milk chocolate containing a higher than normal water content which comprises preparing a dark chocolate containing up to 30% 5 by weight of water, adding a milk powder suspension and mixing under low shear. 2. A process according to claim 1 for manufacturing milk chocolate containing a higher than normal water content which comprises preparing a dark chocolate containing up to 30% by weight of water, adding a milk powder suspension o together with seed crystals of cocoa butter or cocoa butter equivalent, and mixing under low shear. 3. A process according to claim 1 wherein the milk chocolate produced has a water content from 1.5 to 25% by weight based on the weight of the milk 5 chocolate. 4. A process according to claim 1 wherein the dark chocolate containing from 1 to 30% by weight of water is prepared by mixing a dark chocolate material with a water in oil emulsion and mixing sufficiently to disperse the water throughout, but o not so strong as to form a continuous phase. 5. A process according to claim 1 wherein the dark chocolate to which the 1 to 30% by weight of water is added, is prepared by a conventional method including a conching step. 5 6. A process according to claim 1 wherein the oil or fat suspension of milk powder contains an emulsifier in an amount of from 0.1 to 1% by weight. 7. A process according to claim 5 wherein the emulsifier is lecithin, a citric acid 0 ester, a diacetyl tartaric acid ester of mono-and di-glycerides or polyglyceryl polyricinoleate . 8. A process according to claim 2 wherein the oil or fat suspension of milk powder is added to the dark chocolate containing from 1 to 30% water either before or 5 together with seed crystals of cocoa butter or cocoa butter substitute and mixed under low shear. 9. A process according to claim 2 wherein when the oil or fat suspension of milk powder is added to the dark chocolate containing from 1 to 30% water before the seed crystals of cocoa butter or cocoa butter substitute, the mixing is carried out at a low rotational speed at a temperature within the range from 35° to 50°C, for a period of from 1 to 15 minutes after which time the mixture is cooled to a temperature from 30° to 34°C and the seed crystals added and the stirring continued until crystallisation occurs. 10. A process as in claim 9, where the mixing is carried out by pumping the liquid components through a static mixer. 11. A process according to claim 2 wherein when the oil or fat suspension of milk powder is added to the dark chocolate containing from 1 to 30% water together with seed crystals of cocoa butter or cocoa butter substitute, the mixing is carried out in a static mixer at a temperature from 25° to 38°C after which the mass may be directly moulded. 12. A process according to claim 1 wherein the oil or fat suspension of the milk powder is prepared by mixing the appropriate amounts of non-fat milk solids, milk fat, and an emulsifier to provide a slurry. 13. A process according to claim 1 wherein the amount of the oil or fat suspension of the milk powder added to the dark chocolate containing from 1 to 30% water to form the milk chocolate is from 10 to 50% by weight based on the total weight of the milk chocolate. 14.A process according to claim 1 wherein the fat content is lowered by adding non-hygroscopic or emulsifier treated non-fat solids and mixing with the milk powder suspension and the dark chocolate containing from 1 to 30% water. 15 A process according to claim 2 wherein the amount of seed crystals of cocoa butter or cocoa butter substitute is from 1 to 20% by weight based on the weight of the milk powder suspension. 16. A process according to claim 2 in which the seed crystals are added within chocolate or cocoa liquor or cocoa powder. 17. A process according to claim 1 wherein the milk chocolate is not tempered. 18. A coated ice cream wherein the coating is a milk chocolate containing higher than normal amounts of water prepared by a process according to claim 1. 19. A milk chocolate containing higher than normal amounts of water and less than normal amounts of fat and sugar.

Inventors: BECKETT STEPHEN THOMAS, HUGELSHOFER DANIEL, WANG JUNKUAN, WINDHAB ERICH JOSEF, BECKETT, STEPHEN, THOMAS, HUGELSHOFER, DANIEL, WANG, JUNKUAN, WINDHAB, ERICH, JOSEF
Applicants: BECKETT STEPHEN THOMAS, HUGELSHOFER DANIEL, NESTLE SA, WANG JUNKUAN, WINDHAB ERICH JOSEF, BECKETT, STEPHEN, THOMAS, HUGELSHOFER, DANIEL, SOCIETE DES PRODUITS NESTLE S.A., WANG, JUNKUAN, WINDHAB, ERICH, JOSEF
Application year: 2001
Main classification: A23G1
IPC codes: A23G1, A23G9