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Title:
ACIDIC FRESH MILK PRODUCTS CONTAINING PIECES OF CHOCOLATE OR A CHOCOLATE-LIKE PRODUCT AND PREPARATION THEREOF
Document Type and Number:
WIPO Patent Application WO/2006/046139
Kind Code:
A1
Abstract:
The present invention relates to a method for preparing an acidic fresh milk product containing chocolate pieces, which method comprises the following successive steps: a) pasteurization of the chocolate having a fat content of between 46 and 85% by weight, advantageously between 68 and 78% by weight of fat, with a pasteurization strength Fz of between 6000 and 10 000 000 min, advantageously between 10 000 and 500 000 min, preferably 15 000 to 100 000 min; b) cooling of the pasteurized chocolate to a temperature of between 24 and 45°C, preferably between 24 and 38°C; c) continuous-stream injection of the pasteurized, cooled chocolate into a stream of pasteurized acidic milk base having a temperature of between 8 and 16°C, advantageously between 8 and 12°C; d) solidification of the pasteurized chocolate injected; e) cutting the pasteurized, solidified chocolate into pieces and optionally mixing it into the acidic milk base by means of a dynamic mill; f) recovery of an acidic fresh milk product containing pieces of pasteurized chocolate having a fat content of between 46 and 85% by weight, advantageously between 68 and 78% by weight, said product being conserved at a temperature of between 1 and 10°C for a period of between 12 days and 6 weeks.

Inventors:
RABAULT JEAN-LUC (FR)
ESTRADA MIGUEL (MX)
PICK GERARD (FR)
GRUEL JEAN-FRANCOIS (FR)
Application Number:
PCT/IB2005/003405
Publication Date:
May 04, 2006
Filing Date:
October 24, 2005
Export Citation:
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Assignee:
GERVAIS DANONE SA (FR)
RABAULT JEAN-LUC (FR)
ESTRADA MIGUEL (MX)
PICK GERARD (FR)
GRUEL JEAN-FRANCOIS (FR)
International Classes:
A23C9/156; A23G9/28
Domestic Patent References:
WO2004008867A12004-01-29
WO2004068958A12004-08-19
Foreign References:
US5820913A1998-10-13
US6790466B12004-09-14
EP0781510A11997-07-02
US6068865A2000-05-30
US4874618A1989-10-17
EP0770332A11997-05-02
DE4117921A11992-07-30
Attorney, Agent or Firm:
Martin, Jean-jacques (20 rue de Chazelles, Paris cedex 17, FR)
Download PDF:
Claims:
WHAT IS CLAIMED IS:
1. A method for preparing an acidic fresh milk product containing chocolate pieces, which method comprises the following successive steps: a) pasteurization of the chocolate having a fat content of between 46 and 85% by weight, advantageously between 68 and 78% by weight of fat, with a pasteurization strength Fz of between 6000 and 10 000 000 min, advantageously between 10 000 and 500 000 min, preferably 15 000 to 100 000 min; b) cooling of the pasteurized chocolate to a temperature of between 24 and 45°C, advantageously between 24 and 38°C; c) continuousstream injection of the pasteurized, cooled chocolate into a stream of pasteurized acidic milk base having a temperature of between 8 and 160C, advantageously between 8 and 120C; d) solidification of the pasteurized chocolate injected; e) cutting the pasteurized, solidified chocolate into pieces and optionally mixing it into the acidic milk base by means of a dynamic mill; f) recovery of an acidic fresh milk product containing pieces of pasteurized chocolate having a fat content of between 46 and 85% by weight, advantageously between 68 and 78% by weight, said product being conserved at a temperature of between 1 and 1O0C for a period of between 12 days and 6 weeks.
2. The method as claimed in claim 1, wherein the chocolate has a parameter (τ) less than 3, advantageously less than 2, advantageously less than 1, the parameter (τ) being defined by the following equation (1) : τ= ([water] + 0.37) x F + (5.25 x [water] 1.67) x (S+SMP) + (26.2 x [water] 9.6) x C + (61 x [water] 14.5) x (S+SMP) x C, with: [water] is the local free water content of the acidic milk base (in g/g) , F is the fat content of the chocolate (in g/g) , S + SMP is the content of sugars + skimmed milk powder of the chocolate (g/g) , C is the content of dry and defatted cocoa of the chocolate (in g/g) .
3. The method as claimed in claim 1 or 2, wherein the chocolate has a C/ (S+SMP) ratio < 2.3, advantageously less than 1.6, even more advantageously less than 1.
4. The method as claimed in any one of the preceding claims, wherein the acidic milk base is a fermented product containing live ferments, and in particular a yoghurt .
5. The method as claimed in any one of the preceding claims, which method comprises an additional step (g) consisting of the metering, advantageously under a laminar flow hood, of the product obtained in step (f) into a thermoformed or preformed decontaminated pot .
6. The method as claimed in any one of the preceding claims, wherein the pasteurization step (a) is carried out dry.
7. The method as claimed in any one of the preceding claims, wherein step (b) consists in tempering and cooling the chocolate to a temperature of between 24 and 300C.
8. The method as claimed in any one of the preceding claims, wherein step (c) is carried out by injection of the chocolate into the middle of the stream of acidic milk base, the stream of chocolate being parallel to the stream of acidic milk base and the linear speed of the stream of chocolate on leaving the injecting device being equal, to within ± 40%, to that of the stream of acidic milk base.
9. The method as claimed in any one of the preceding claims, wherein a large amount of chocolate is injected in step (c) by proportion to the acidic milk base and the rest of the acidic milk base is added in step (e) so as to obtain, in step (f) , an acidic fresh milk product containing the desired amount of chocolate pieces.
10. The method as claimed in any one of the preceding claims, wherein the solidification time in step (d) is between 50 and 600 s.
11. The method as claimed in any one of the preceding claims, wherein step (e) also comprises the addition and the mixing into the milk base of other ingredients, advantageously chosen from sweetened syrups, cream, fruit preparations or cocoa.
12. The method as claimed in any one of the preceding claims, wherein the longest dimension of the chocolate pieces obtained in step (e) is between 1 and 6 mm, advantageously between 4 and 10 mm.
13. The method as claimed in any one of the preceding claims, which method comprises an intermediate step (al) between steps (a) and (b) , consisting of storage with stirring of the pasteurized chocolate at a temperature of between 28 and 75°C, advantageously between 65 and 75°C, optionally without overpressure.
14. The method as claimed in any one of the preceding claims, wherein the milk product obtained in step (f) contains between 0.5 and 10% by weight of chocolate pieces relative to the total weight of the milk product, advantageously between 2 and 5% by weight, advantageously between 4.5 and 10% by weight.
15. The method as claimed in any one of the preceding claims, which method comprises a step (α) , prior to step (a) , consisting of preparation of the chocolate, advantageously by mixing the fat, the dark chocolate and, optionally, the cocoa mass and/or the cocoa powder.
16. The method as claimed in claim 15, wherein the same tank is used for steps (α) , (a) and (al) .
17. The method as claimed in any one of the preceding claims, which method is carried out in a device that has a nonreturn valve for separating the stream of chocolate obtained in step (b) from the stream of acidic milk base.
18. An acidic fresh milk product containing chocolate pieces, which contains between 4.5% and 10% by weight of chocolate relative to the total weight of the milk product, wherein the chocolate is pasteurized and has a fat content of between 46 and 85% by weight, advantageously between 68 and 78% by weight, and wherein the acidic fresh milk product containing chocolate pieces is conserved at a temperature of between 1 and 100C for a period of between 12 days and 6 weeks.
19. The product as claimed in claim 18, which can be obtained by means of the method as claimed in any one of claims 1 to 17.
20. The product as claimed in either one of claims 18 or 19, wherein the chocolate has a parameter (τ) less than 3, advantageously less than 2, advantageously less than 1, the parameter (τ) being defined by the following equation (1) : τ = ( [water] + 0.37) x F + (5.25 x [water] 1.67) x (S + SMP) + (26.2 x [water] 9.6) x C + (61 x [water] 14.5) x (S + SMP) x C, with: [water] is the local free water content of the acidic milk base (in g/g) , F is the fat content of the chocolate (in g/g) , S + SMP is the content of sugars + skimmed milk powder of the chocolate (g/g) , C is the content of dry and defatted cocoa of the chocolate (in g/g) .
21. The product as claimed in any one of claims 18 to 20, which is a fermented product containing live ferments, and in particular a yoghurt.
22. The product as claimed in any one of claims 18 to 21, wherein the longest dimension of the chocolate pieces is between 1 and 6 mm, advantageously between 4 and 10 mm.
23. The product as claimed in any one of claims 18 to 22, wherein the chocolate has a C/ (S+SMP) ratio < 2.3, advantageously less than 1.6, even more advantageously less than 1.
24. The product as claimed in any one of claims 18 to 23, wherein the chocolate pieces are dispersed homogeneously in the acidic fresh milk product .
25. A multilayer fresh food product containing at least one layer of product as claimed in any one of claims 18 to 24.
26. A device for implementing the method as claimed in any one of claims 1 to 16, which comprises a means for pasteurization (10) of the chocolate, a means for cooling (20) of the pasteurized chocolate, a means for continuousstream injection (32) of the cooled pasteurized chocolate, an inlet (30, 31) for the stream of pasteurized acidic milk base, a dynamic mill (36) for the solidified chocolate, and an outlet (37) for the acidic fresh milk product containing pieces of pasteurized chocolate.
27. The device as claimed in claim 26, which also comprises a means (38) of metering into a thermoformed or preformed decontaminated pot .
28. The device as claimed in either one of claims 26 and 27, which also comprises a means of adding (35) and a means of mixing an ingredient other than chocolate.
29. The device as claimed in any one of claims 26 to 28, wherein the mixing means (1) is the dynamic mill (36) .
30. The device as claimed in any one of claims 26 to 29, which also comprises a means of storage (10) , with stirring, of the pasteurized chocolate.
31. The device as claimed In any one of claims 26 to 30, which also comprises a means of preparation (8) of the chocolate.
32. The device as claimed in any one of claims 26 to 31, wherein the same tank (10) is used as means of preparation of the chocolate, means of pasteurization of the chocolate and means of storage of the pasteurized chocolate.
33. The device as claimed in any one of claims 26 to 32, which comprises a nonreturn valve (22) between the cooling means (20) and the injecting means (32) .
34. The device as claimed in any one of claims 26 to 33, wherein a deflector/support blade (41) is located before the dynamic mill (36) .
Description:
TITLE: ACIDIC FRESH MILK PRODUCTS CONTAINING PIECES OF CHOCOLATE OR A CHOCOLATE-LIKE PRODUCT, AND PREPARATION THEREOF

The present invention relates to acidic fresh milk products containing pieces of chocolate or a chocolate- like product, to a method for the preparation thereof and to a device for implementing said method.

The use of chocolate pieces in fresh milk products poses technical problems that are very different from those conventionally encountered in other food areas (chocolate making, confectionery, cookie production, ice cream, etc.) . In particular, the following problems are involved:

microbiological contamination: certain molds, yeast and vegetative bacteria naturally present in chocolate develop on contact with the water content of the fresh milk product. It is necessary to sterilize or pasteurize the chocolate; however, conventional pasteurization scales are ineffective on chocolate, because of its low Aw. In addition, the materials and methods used must be ultra-clean in order to prevent bacterial contamination or re-contamination; poor water resistance: a standard chocolate is soft after 5 hours in a yoghurt. However, it is necessary for the chocolate to keep its crunchiness.

Fresh milk products that contain pieces of unpasteurized chocolate (conventional chips, filled or not filled) are known in the prior art. However, in this case, preserving agents must be used or the shelf-lives of these milk products are short (< 12 days) .

Zentis patent application EP 976 333 describes chocolate

pieces (chips) obtained by crystallization of the chocolate upon contact with a cold gas (and not with an aqueous liquid) . These chocolate pieces can then be used as milk product additives. However, this method is expensive (in terms of investment and operating costs: the crystallization of the chocolate is carried out in a tower at a negative temperature of between -40 and -120 0 C, in order for it to be very rapid) and complex and is only available in a single factory in the world (Germany) . In addition, the chocolate pieces can be more readily contaminated before they are mixed with the fresh milk product. That patent does not deal with the microbiological aspect, in particular how to prevent recontamination during the steps in which the chocolate is crystallized and mixed with the fresh milk product.

Now, it is easier to maintain the sterilized or pasteurized state of the chocolate by confining the crystallization of the chocolate in a closed chamber

(piping or tank) , than by crystallizing it in contact with the air or- with a gas.

Patent application WO 00/70960 describes a solid chocolate or chocolate-like product, advantageously in the form of grains, that can be brought into contact with a wet mass such as a milk base. Standard chocolate (i.e. chocolate which has not undergone thermal decontamination) is contaminated; now, nothing is suggested with regard to the need to pasteurize or sterilize the chocolate in order to prevent microbiological problems due to the contact with the acidic fresh milk products. Furthermore, nothing is indicated regarding the manner in which this pasteurized state can be maintained until the product reaches the consumer, nor even until the product is packaged.

Patent application EP 615 692 describes a method of

crystallizing chocolate by injection into a neutral cold dairy mousse, followed by milling of the band of chocolate obtained. However, this method requires sterilization of the chocolate, which modifies its organoleptic qualities, and the use of a very bitter chocolate (between 1 and 10% by weight of sugar, advantageously between 1 and 3% by weight of sugar) , i.e. not very sweetened, the product obtained therefore not being very satisfactory for the consumer. Moreover, in order to mask this bitterness as much as possible, it is necessary to limit the size of the chocolate particles

(between 1 and 4 mm) . Wet sterilization, as described in patent EP 1 100 343 could be envisioned, and this would minimize the organoleptic damage, but such sterilization has consequences with respect to the water resistance of the sterilized chocolate obtained and therefore with respect to the risk of a loss of crunchiness of the chocolate pieces during the period of conservation of the product. In addition, the need to sterilize the chocolate complicates the method, making it less productive and therefore more expensive in terms of investment and operating costs.

The patent application *by General Mills (WO 2004/008867) describes the direct injection of chocolate into a very cold yoghurt (0 to 5°C, preferably 0 to 3 0 C) in order to allow "spontaneous" fragmentation of the chocolate into pieces in the yoghurt, without requiring any subsequent cutting/milling of the chocolate. That document indicates that, if the fresh milk product, during injection of the chocolate, has a temperature above 7°C, there are risks of microbial contamination. In addition, the chocolate used in this method has a fat content of 24 to 45% by weight, which does not make it possible to maintain the crunchiness throughout the conservation of the product.

This is because maintaining the crunchiness requires the use of chocolate with a higher fat content (typically > 65% by weight of fat for a dark chocolate, preferably approximately " 75% by weight of fat) . This increase in fat content is necessary for this aim of obtaining a crunchier texture, despite the new technical difficulties that it engenders. A chocolate with a higher fat content, which is much more fluid in the molten state, means that:

- there are risks of sedimentation of the solid particles (sugar, cocoa, etc.) in suspension in the chocolate (as long as this chocolate is not crystallized) , hence a heterogeneous formula and risks of blocking; - there is a risk of the chocolate mixing with the yoghurt before the former has crystallized (giving a brown yoghurt, or even a less crunchy chocolate); there is a greater need for refrigeration: in order to absorb the latent heat from crystallization of a chocolate containing 75% by weight of fat, 2.3 times more refrigeration is needed than for a chocolate containing 32% by weight of fat.

The device described in the General Mills patent would not make it possible to use such fatty chocolates: firstly, there would, with the injection device indicated

(perpendicular to the powerful flow of yoghurt in order to break up the chocolate) , be a risk of the chocolate mixing with the yoghurt before it had crystallized (giving a brown yoghurt) ; in addition, the additional need for refrigeration in order to crystallize the chocolate with a higher fat content would not longer allow the spontaneous solidification and fragmentation described.

Surprisingly, the inventors of the present application

have discovered that it is possible to obtain acidic

(pH < 4.8, advantageously from 4.2 to 4.8) fresh milk products containing pieces of pasteurized chocolate or chocolate-like product, and having a shelf life of between 12 days and 6 weeks at a temperature of between 1 and 1O 0 C, by implementing a method preventing recontamination at all stages until consumption, which is less expensive (in terms of investment and operating costs) , more flexible and more productive than those proposed in the state of the art. Moreover, the chocolate pieces keep their crunchiness throughout the shelf life of the milk product, without requiring the use of preserving agents or dual compartments.

The method discovered by the inventors allows direct injection of the chocolate into the fresh milk product, and not via a preparation, which makes it possible to easily regulate the percentage of chocolate pieces present in the final product independently of the rest of the recipe (via a preparation, water, sugar, texturing agents, etc., are also added) and to obtain fresh milk products having a content of chocolate pieces that may be high (advantageously > 4.5% by weight) .

Moreover, by virtue of this original method, the microbiological stability of the chocolate pieces in contact with the acidic fresh milk product is ensured with simple pasteurization of the chocolate. This is because, in acidic fresh milk products (fermented or acidification via ingredients) , pasteurization of the ingredients (before fermentation or acidification of the milk) is sufficient (no need to sterilize, since sporulated bacteria do not grow at pH < 4.8/0 to 10°C/30 days) .

Thus, the advantages of using acidic fresh milk products

(of the yoghurt or fromage frais type) according to the method of the present invention, compared with neutral fresh milk products (pH > 5.0) are as follows:

1. A pasteurized chocolate is sufficient.

It is much easier to pasteurize chocolate than to sterilize it.

2. It is possible to pasteurize the piping dry, with chocolate in - certain cases -(whereas, in the sterile version, in-place cleaning, sterilizing with hot water or with steam, and then drying had to be carried out) .

3. There is better control of recontamination. In addition, in the event of accidental contamination, there is no substantial pathogenic risk (essentially the appearance of a modifying flora) .

The present invention therefore relates to a method for preparing an acidic fresh milk product containing chocolate pieces, which method comprises the following successive steps:

a) pasteurization of the chocolate having a fat content of between 46 and 85% by weight with a pasteurization strength Fz of between 6000 and 10 000 000 min, advantageously between 10 000 and 500 000 min, even more advantageously between 15 000 and 100 000 min;

b) cooling of the pasteurized chocolate to a temperature of between 24 and 45 0 C, advantageously between 24 and 38 0 C;

c) continuous-stream injection of the pasteurized, cooled chocolate into a stream of pasteurized acidic milk base having a temperature of between 8 and 16 0 C, advantageously between 8 and 12 0 C;

d) solidification of the pasteurized chocolate injected;

e) cutting the pasteurized, solidified chocolate into pieces and optionally mixing it into the acidic milk base by means of a dynamic mill;

f) recovery of an acidic fresh milk product containing pieces of pasteurized chocolate having a fat concentration of between 46 and 85% by weight, said product being conserved at a temperature of between 1 and 10 0 C for a period of between 12 days and 6 weeks.

For the purpose of the present invention, the term "acidic milk base" or "acidic milk product" is intended to mean any milk product that is fermented or acidified via ingredients (advantageously, with lactic acid, citric acid or phosphoric acid) . Its pH is advantageously less than 4.8. It i " s advantageously between 4.2 and 4.8. In particular, it may be a fromage frais or a fermented product containing live ferments (for example, sour cream, kefir, or the like) and in particular a yoghurt or similar fermented milk specialty products (fermented with lactic acid bacteria, such as active bifidus or L. casei) . Advantageously, it is not a mousse. Advantageously, it is a stirred yoghurt. Advantageously, the product is fermented by the addition of live ferments such as, for example, Lactobacillus bulgaricus, Streptococcus thermophilus and/or Lactobacillus acidophilus and/or bifidus.

Advantageously, the milk used in the milk base is cow's milk. However, other milks can be used as complete or partial substitution for the cow's milk, such as, for example, goat's milk, yew's milk, buffalo milk or mare's milk, or less advantageously milks of vegetable origin,

such as soya milk, coconut milk or oat milk.

For the purpose of the present invention, the term "chocolate" is intended to mean chocolate and chocolate- like products.

For the purpose of the present invention, the term "chocolate-like product" is intended to mean any confectionery fatty mass, with a water content < 4% by weight (before being brought into contact with an aqueous product) , containing a continuous fatty phase consisting of one or more fats of vegetable or animal origin and whose properties are similar to those of cocoa butter

(crunchy texture) . These fatty masses are generally called coating chocolate or compound.

This chocolate or this chocolate-like product can be flavored with caramel, with coffee, with mint, etc., as a supplement or as a substitution for the cocoa.

In an advantageous embodiment of the invention, the chocolate comprises between 65 and 78% by weight of fat, advantageously between 68 and 78% by weight of fat, advantageously between 74% and 76% by weight of fat, relative to the total weight of the chocolate. In general, the fat is cocoa butter. It is, however, possible to replace up to 20% by weight of the cocoa butter with anhydrous milk fat (AMF) or to replace all or some of the cocoa butter with one or more vegetable fats having an SFC at 1O 0 C (solid fat content) of greater than 50% by weight. In the case of the chocolate-like products, the fat can also be solely a fat of vegetable origin, in particular lauric fats: for example, hydrogenated fractionated palm kernel oil (sold by Fuji Oil Europe) . These lauric fats should not be combined with cocoa butter for reasons of crystallization

(eutectic) incompatibility. The cocoa butter contained in cocoa powder (10-12% fat) is, however, tolerated, but care will be taken to maintain the cocoa butter/total fat ratio at preferably < 5%, so as to maximize the crunchiness.

Very high fat chocolates are unstable: there is rapid sedimentation due to the low viscosity, hence a heterogeneity in the recipe, and therefore a heterogeneity in the taste and in the water resistance. Preferably, the chocolate purchased will have a low fat content, so as to have a viscosity > 0.5 Pa. s at 40 0 C (according to the "Casson" method, OICC No. 10 (1973)) , and the remainder of the fat content will be adjusted at the site of pasteurization. This prevents settling out in transport tankers that do not have stirring, for example.

In an advantageous embodiment of the invention, the chocolate has a sugar concentration of greater than 5% by weight, advantageously greater than 10% by weight, even more advantageously greater than 11% by weight, relative to the total weight of the chocolate or chocolate-like product. Advantageously, this sugar content is approximately 14% by weight, relative to the total weight of the chocolate or chocolate-like product. The sugars are in particular monosaccharides and disaccharides . Among monosaccharides, mention may be made of fructose, galactose or glucose. Among disaccharides, mention may in particular be made of sucrose, which is the sugar commonly used for producing chocolate, but the sucrose can be partially or completely replaced with another disaccharide, such as lactose, for example in an amount of 0 to 50% by weight, or with polyols which, at the jacket temperature during the pasteurization or sterilization step, do not melt and do not release crystallization water. These are, for example, mannitol

and maltitol. The preferred variant is, however, sucrose.

In a particular embodiment of the invention, the chocolate has a parameter (τ) less than 3, advantageously less than 2, advantageously less than 1, the parameter (τ) being defined by the following equation (1) : τ= (-[water] + 0.37) x F + (5.25 x [water] - 1.67) x (S+SMP) + (26.2 x [water] - 9.6) x C + (61 x [water] - 14.5) x (S+SMP) x C, with: - [water] is the local free water content of the acidic milk base (in g/g) ,

F is the fat content of the chocolate (in g/g) , S + SMP is the content of sugars + skimmed milk powder of the chocolate (g/g) , - C is the content of dry and defatted cocoa of the chocolate (in g/g) .

The local free water content [local free water] is defined by the following equation (2) : [local free water] = [total water] xA w 25° c/ (100-FM) ■ in which:

[local free water] is given in grams of water per gram of acidic milk base;

FM is the fat of the acidic milk base, expressed in grams of fat per 100 grams of acidic milk base;

[total water] is given in grams of water per 100 grams of acidic milk base.

For example, for a non-fat wet base containing 77% of water and having an A w 25° c of 0.96, the local free water content is 73.9%.

An acidic milk base has a local free water content of between 45 and 88%.

For an application with a small thickness of chocolate

(< 3 mm) , it is necessary that τ < 2. The thinner the thickness of the chocolate, the lower τ must be in order for the chocolate to keep its crunchiness.

Thus, according to the desired thickness of the chocolate pieces, the value of τ must not exceed a limiting value in order to ensure water resistance and therefore a crunchiness that is sufficient. The greater the thickness, the higher the limiting value of τ may be. For this reason, those skilled in the art will be in a position to choose the optimal composition of the chocolate according to the desired thickness. Similarly, the value of τ will have to be chosen according to the duration of conservation and the temperature of conservation of the milk product containing the chocolate pieces. The shorter the duration or the lower the temperature, the higher this value may be. In general, τ is advantageously less than 2, preferably less than 1.6.

The composition of the chocolate having the appropriate characteristics in the context of the present invention is therefore defined in particular by means of a test described in the form of a mathematical equation which means that those skilled in the art do not have to carry out experiments. However, where required, an experimental procedure that allows those skilled in the art to determine the chocolate compositions which satisfy the aims that the invention proposes to achieve is indicated below.

For example, the test which consists in bringing slices of chocolate 1.5 ± 0.2 mm thick and 20 mm in diameter into contact with an agar gel having a determined local free water content of 74% is carried out. The chocolate slices are obtained after tempering and cooling of the chocolate to 13°C, and storage for 2 days at 2O 0 C and

then for 12 hours at 10 0 C. The gel is poured into syringes which are cut at their end and then covered with the slice of chocolate and are then closed again with a stopper. The whole is stored for 35 days at 1O 0 C and the water uptake of the slice of chocolate is measured at D35 by the "Karl Fischer" method, OICC No. 105 (1988) .

The compositions which satisfy the criteria of the invention are those whose percentage water uptake after 35 days of storage at 10 0 C will be < 17.7%; table 1 below gives an indication of the percentages of water uptake after 35 days at 10 0 C as a function of the water resistance of the chocolate.

Table 1: Percentages of water uptake in g per 100 g after 35 days at 1O 0 C as a function of the water resistance of the chocolate

A gel composition having a local free water content of approximately 74% is given below in table 2.

Table 2: % composition, by weight, of gel having a local free water content of approximately 74%

The chocolate used in the context of the present invention may be dark chocolate, milk chocolate or white chocolate.

In the case of milk chocolate or white chocolate, some or all of the dry and defatted cocoa is replaced with skimmed or non-skimmed powdered milk.

Advantageously, the composition of the chocolate according to the present invention is such that the C/ (S+SMP) ratio is < 2.3, advantageously less than 1.6, even more advantageously less than 1 (C = the content of dried defatted cocoa of the chocolate (in g/g) , S+SMP = content of sugar + skimmed milk powder of the chocolate (in g/g) ) .

Moreover, in the case of the use of other milk powder derivatives (lactoserum, buttermilk, permeate, lactoprotein, etc.) , their non-fat component will be counted as V SMP Λ in the formulas above. In a non- advantageous variant, polyols or other filling sweeteners can be substituted for the sugar and are then counted as such (S) in the above formulas.

All the water-resistant chocolate formulae described in

patent application WO 00/70960 can be used in the context of the present invention.

Advantageously, the chocolate used in the context of the present invention corresponds to the formulae indicated in table 3 below:

Table 3: % composition, by weight, of the chocolate formulae

In these formulae: the cocoa mass contains, as % by weight: 1.7% water,

53.4% fat and 44.95% dry defatted cocoa; its water content is < 1%, the particle size thereof is advantageously fine (minimum 90% of particles < 20 μm; maximum 0.2% of particles > 75 μm) and the contamination thereof is advantageously of the order of 1000 cfu/g; the dark chocolate contains, as % by weight: 0.5% water, 27.7% fat (approximately 0.3% of which is lecithin) , 22.3% dry defatted cocoa and 49.5% sugar; preferably, the particle size thereof measured with a

Palmer is < 30 μm, and the contamination thereof is of the order of < 1000 cfu/g; the- cocoa powder containing 11% fat contains, as % by weight: 4% water, 11% fat and 85% dry defatted cocoa.

Advantageously, these three constituents, along with the cocoa butter, are sold by the company Barry-Callebaut .

Advantageously, the chocolate-like product used in the context of the present invention corresponds to the formulae indicated in table 4 below:

Table 4: % composition, by weight, of the chocolate-like product formulae

The composition of the recipes of the lauric chocolate- like products is given in table 5 below. Advantageously,

the particle size thereof measured with a Palmer is

< 30 μm, and the contamination thereof is advantageously

< 1000 cfu/g.

Table 5: % composition, by weight, of the recipes of the lauric dark chocolate-like products

The hydrogenated and fractionated vegetable fat used in tables 4 and 5 is hydrogenated palm kernel stearin (i.e. hydrogenated and fractionated) . Two advantageous examples are available from Fuji Oil Europe (ref: Palkena H50 G or HB7 G) . In particular the solid fat content of these two plant fats is given in table 6 below.

Table 6: Solid fat content (SFC) as a proportion of solid fat/total fat (as %) at a given temperature

HPKS Palkena, HPKS Palkena,

Cocoa butter Ref H50 G Ref HB7 G

SFC at 10 0 C 84.3

SFC at 15 0 C 78.4

SFC at 20 0 C 71 > 91 > 90

SFC at 25 0 C 62.6 82-91 73-83

SFC at 30 0 C 37.9 38-47 26-35

SFC at 35 0 C 0.8 < 5 < 5

SFC at 40 0 C 0

In a particular embodiment of the invention, the method according to the present invention comprises a step (α) , prior to step (a) , consisting of preparation of the chocolate, advantageously by mixing the fat and the chocolate, and optionally the cocoa mass and/or the cocoa powder. Advantageously, the ingredients used are cocoa mass, dark chocolate, cocoa powder containing 11% by weight of fat and cocoa butter in the case of chocolate, and the lauric dark chocolate-like product, hydrogenated and fractionated vegetable fat and cocoa powder 10-12 in the case of the chocolate-like product. Advantageously, the proportions used are those indicated in tables 3, 4 and 5 for formulae 1, 2, 3 and 4 and recipes 1 and 2.

In a particular embodiment of the invention, the chocolate, prepared on site in step (α) or purchased, is deaerated under vacuum before it is used in the method according to the present invention (i.e. before step (a) of the method) . Such a deaeration can make it possible to obtain a better effectiveness of the thermal treatment and a better water resistance (more compact chocolate) .

Step (a) of the method according to the present invention

therefore consists of pasteurization of the chocolate with a pasteurization strength Fz of between 6000 and 10 000 000 min, advantageously between 10 000 and 500 000 min, even more advantageously between 15 000 and 100 000 min.

Surprisingly, for a dark chocolate, no organoleptic degradation 'occurs with these scales.

In 1997, PCSA (Danone Group) modeled the thermo- resistance of A. niger spores in artificial contamination in chocolate (< 1% of water) :

• Decimal reduction time D (time necessary to reduce by 90%, i.e. to divide by 10, a population of a given microorganism at a given temperature) at 70 0 C: D 70 =C = 2000 min; 2000 min at 70 0 C (reference temperature) are therefore required to destroy the population of A. niger by 90%.

• Z (increase in temperature in 0 C which makes it possible to divide D by 10) = 7.65°C; it is therefore necessary to raise the temperature by 7.65°C in order to reduce D 10-fold (therefore

D 7 7.65°C = 200) .

A. niger is one of the most thermoresistant micro¬ organisms of those that must be destroyed during pasteurization. These data are used to calculate the pasteurization strength Fz according to formula (3) below:

Fz = time x io (T - 7O)/z time = pasteurization time at T in min Fz: pasteurization strength in min T: pasteurization temperature in 0 C

In reality, since the temperature is not constant during

the thermal treatment, Fz is calculated by time x temperature integration, as is conventionally done in the food preservation industry (appertization) .

The effectiveness of pasteurization is then calculated: EP = Fz/D 70° c/ which measures the logarithmic decrease in the population for the given thermal treatment.

For example, Fz = 6000 min can correspond to a thermal treatment of 6000 min at 70 0 C or 0.72 min at 100 0 C or 1 min at 98.9 0 C. These treatments reduce the population of A. niger 1000-fold (3 Log) . Fz = 10 000 000 min can correspond to a thermal treatment of 13.1 min at 115°C.

A little water, preferably in the form of steam, can be injected in order to pasteurize the chocolate during step

(a) . It may be, for example, a proportion of 0.5 to 1% by weight relative to the total weight of the chocolate.

This can make it possible to improve the pasteurization if the starting materials are very contaminated: it is not then necessary to evaporate the water introduced, given the small amounts used.

In an advantageous embodiment, the pasteurization step (a) is carried out dry. Advantageously, this step (a) is carried out by heating, optionally under pressure.

Advantageously, this step (a) comprises the following successive steps:

1. Heating, advantageously using a device equipped with a double-walled jacket, to a temperature > 74 0 C, advantageously to a temperature of between 90 and 120 0 C, advantageously to a temperature of approximately 100°C+/-5°C so as to obtain Fz > 6000 min,

2. Cooling to a temperature < 75 0 C, advantageously using a device equipped with a double-walled jacket.

During the heating in the pasteurization step (a) , a little water evaporates into the "overhead of the tank" and it is advantageous (but not strictly necessary) to remove it, in order to increase the water resistance of the chocolate and to limit sugar aggregates. In particular, two solutions can be envisioned for removing this water:

1. If the heating is carried out at atmospheric pressure: the gases and the steam can exit via a sterile filter (or sintered glass) ;

2. If the heating is carried out under pressure using a device equipped with a closed pasteurization tank, the steam can be degassed just after the end of pasteurization (before cooling) by being placed in the open air and/or by being placed under vacuum.

Option 2 gives a slightly greater effectiveness of pasteurization of the chocolate, but may cause some sugar aggregates in the pasteurized chocolate.

In an advantageous embodiment, the chocolate is pasteurized during step (a) by means of a batch method, advantageously in a device equipped with a pasteurization tank that has a double-walled jacket, advantageously equipped with a stirrer that scrapes the walls.

Advantageously, the heating fluid in the double-walled jacket is hot water (optionally overheated for temperatures > 100 0 C) , steam (in particular for pasteurization temperatures > 100 0 C) or any other heat-

transfer fluid (oil, for example) .

Steam - allows shorter pasteurization cycle times, since the heating is more rapid than a loop of hot water. Advantageously, the steam pressure in the double-walled jackets will be < 150 KPa in absolute pressure, so as to limit the wall temperature to a temperature < 111°C.

Advantageously, step (a) of the method can be carried out:

batchwise; the pasteurization tank can thus serve as a buffer tank before the metering device/use (for a continuous production, 2 tanks are required, in parallel) . Advantageously, the tank and the piping of the device implementing the method according to the present invention are pasteurized at the same time as the chocolate;

- continuously, the device used for the pasteurization comprising no pasteurization tank, but a heat exchanger, for example with a scraped surface (with an installation devoted to pasteurization, there is never any need for cleaning: it is sufficient to pasteurize the downstream piping with chocolate according to the scale above, and to send the chocolate insufficiently pasteurized into the starting tank so as to recycle it) .

Advantageously, this step (a) makes it possible to obtain a pasteurized chocolate comprising a contamination of less than 1 cfu/g of bacteria, yeast and mold, excluding bacterial spores, which cannot germinate at a temperature of less than or equal to 1O 0 C, advantageously less than 1 cfu/100 g, advantageously less than 1 cfu/kg (1 cfu/g = 1000 cfu/kg) .

Advantageously, the same tank is used for implementing steps (a) and (α) .

In a particular embodiment of the invention, the method according to the present invention comprises an intermediate step (al) , between steps (a) and (b) , consisting of storage with stirring of the pasteurized chocolate at a temperature of between 28 and 75°C, advantageously between 65 and 75°C, optionally without overpressure.

Once pasteurized (step (a) ) , the chocolate can be stored under pressure (step (al) ) , advantageously at a temperature of between 28 and 50 0 C, advantageously at a pressure of between 10 and 30 KPa. When the storage temperature is < 36°C, the lower the temperature, the shorter the storage time will have to be (risk of solidification) . For example, for formula 1 indicated in table 3, storage at 33 0 C can be carried out for approximately 40 hours without too marked an increase in viscosity (its viscosity at 33°C is of the order of 0.26 Pa.s under a strain of 150 Pa) .

In a variant of the method according to the present invention, the storage is carried out under pressure at a temperature of between 28 and 38 0 C, preferably between 30 and 34 0 C.

In another variant of the method according to the present invention, the storage is carried out under pressure at a temperature of between 38 and 50 0 C, advantageously at a temperature of 45 0 C.

In another variant of the method according to the present invention, the storage is carried out at a temperature of

between 65 and 75°C without overpressure, i.e. at atmospheric pressure.

Whatever the variant, the chocolates, which are very fluid, must be permanently stirred, in order to prevent settling out of the solid particles in suspension and fat separation.

In the method according to the present invention, step (al) is carried out in a device equipped with an intermediate buffer tank. However, advantageously, the chocolate is stored in the pasteurization tank of step (a) . Thus, the same tank is used for steps (a) and (al) .

Even more advantageously, the same tank is used for steps (α) , (a) and (al) .

Moreover, it is advisable to maintain the pasteurization of the chocolate before it is injected during step (c) . If the pasteurized chocolate remains stored in the pasteurization tank during step (al) , this avoids having to pasteurize a downstream tank, and the tank is thus pasteurized at each batch at the same time as the chocolate. Since the chocolate is anhydrous, it is not necessary to clean between two batches, unless the flavors or colors of the chocolate are incompatible. No time is therefore lost due to cleaning/pasteurization of the tank. In order to prevent any recontamination, the tank is advantageously pressurized by a sterile gas source (typically, 10 to 30 KPa) .

Since the chocolate is incompatible with water, all the pipework downstream of the injection step (c) , in the device for implementing the method according to the present invention, is advantageously pasteurized dry, in particular at the same time as the pasteurization of the

chocolate at each batch, advantageously with a device having a double-walled jacket at 100°C/10 to 20 min, after cleaning or without cleaning. Other dry sterilization techniques-,exist, for example with hot fat (100°C/10 min) .

Alternatively, the pipework downstream of the injection step (c) , in the device for implementing the -method according to the present invention, can also be pasteurized conventionally by cleaning in place, and then pasteurization with hot water or steam: however, it is necessary to drain off the water and preferably dry the installation before sending the pasteurized chocolate thereto (sterile gas stream, or vacuum, heated by double- walled jackets, for example filled with steam at 110 KPa in absolute pressure) .

If step (al) is carried out in a device equipped with an intermediate buffer tank, i.e. steps (al) and (a) are not carried out in the same tank, the following two cases exist: the storage (step (al) ) is carried out at a temperature of less than 60-65 0 C. The intermediate buffer tank will then have to be pasteurized during the 1st use and each time the pasteurized state is lost (since the chocolate is virtually anhydrous, no microbial development can take place, except in an exceptional case: maintenance, etc.) . This may be carried out conventionally (cleaning, then hot water sanitization, then evaporation) , or preferably by heating ensuring a pasteurization strength Fz > 6000 min (for example, 22 h at 75°C) , preferably Fz > 20 000 min; the storage (step (al) ) is carried out at a temperature > 75 0 C so as to have "continuous" pasteurization.

The above steps (a) and (al) should avoid the incorporation of air, which reduces the water resistance of the chocolate. Optionally, degassing (for example, by- placing the pasteurization and/or batch storage tank under vacuum) can be carried out .

In the context of the present invention, step (b) of the method according to the present invention consists in cooling the pasteurized chocolate to a temperature of between 24 and 45°C, advantageously between 24 and 38 0 C.

In a particular embodiment of the invention, step (b) consists in tempering and cooling the chocolate to a temperature of between 24 and 30 0 C. Advantageously, if the chocolate is not tempered, it is cooled to a temperature of between 30 and 45 0 C, advantageously between 30 and 40 0 C.

The tempering of the chocolate (presolidification) is not obligatory in fresh products, i.e. in the method according to the present invention, as it is for conventional applications stored at ambient temperature. However, it accelerates the solidification of the chocolate and slightly improves its crunchiness. The tempering may be carried out by means well known to those skilled in the art in the chocolate making industry. It may thus be very simplified, since, although in the chocolate making industry only V-shaped (stable) chocolate crystals are selected, chocolate crystals of any shape can be accepted here, since the storage conditions according to the present invention will prevent any whitening. The essential aim of the tempering is therefore simply to accelerate the solidification of the chocolate on contact with the fresh milk product during step (d) of the method according to the present invention, in particular by starting from a lower

chocolate temperature and by having already crystallized part of the fat of the chocolate.

Advantageously, step (b) is carried out either directly in the storage tank of the optional step (al) , or on line, advantageously using a device equipped with a heat exchanger (for example, a scraped-surface exchanger) . The on-line scraped-surface exchanger allows the chocolate to be cooled to a lower temperature, since the chocolate does not remain at this temperature for very long and will not have the time to solidify.

In the method according to the present invention, step (c) consists of the injection of the chocolate into a stream of pasteurized acidic milk base having a temperature between 8 and 16 0 C, advantageously between 8 and 12 0 C, and advantageously between 8 and 10 0 C.

The pasteurized and optionally fermented, acidic milk base is obtained according to methods well known to those skilled in the art. In particular, the method for obtaining a fermented pasteurized acidic milk base comprises the following successive steps:

- homogenization of the milk base, - pasteurization of the milk base,

- cooling of the milk base,

- seeding,

- fermentation to the desired acidity.

Briefly, the method begins with raw milk which may also contain a combination of whole milk, skimmed milk, condensed milk, dry milk (defatted dry extract of milk or equivalent) , category A lactoserum, cream and/or other milk fraction ingredients, such as, for example, buttermilk, lactoserum, lactose, lactalbumin, lactoglobulin or lactoserum modified by complete or

partial removal of lactose and/or minerals or other milk ingredients so as to increase the defatted solid content, which are mixed so as to provide the desired fat and solid contents. Although not preferred in the context of the present invention, the milk base may contain a filling milk constituent, i.e. a milk ingredient of which a portion consists of a non-milk ingredient, for instance an oil or soya milk.

The injection of the chocolate into the acidic milk base according to step (c) of the method according to the present invention is carried out in a continuous stream. The chocolate is therefore advantageously injected in the form of "strips" of varied cross section (round, rectangular, cross-shaped, etc.) .

Advantageously, the injecting device used deposits the stream of chocolate in the middle of the stream of acidic milk base. Advantageously, the stream of milk base is parallel to the stream of injected chocolate. Advantageously, the linear speed of the stream of chocolate on leaving the injecting device is equal, to within ± 40%, to that of the stream of acidic milk base.

In a particular embodiment of the invention, step (c) is carried out by injection of the chocolate into the middle of the stream of acidic milk base, the stream of chocolate being parallel to the stream of acidic milk base and the linear speed of the stream of chocolate on leaving the injecting device being equal, to within + 40%, to that of the stream of acidic milk base.

The injection flow rate should be calculated according to the desired proportion of chocolate in the acidic fresh milk product.

In order to create an even vein of chocolate and to prevent any mixing, the linear speed of the chocolate should advantageously be as close as possible to that of the acidic milk base (carrier fluid) . Advantageously, the flow between the stream of acidic milk base and the stream of chocolate should be laminar (same speed) before and after the injection step (c) so as to prevent mixing between the non-solidified chocolate and the acidic milk base.

Advantageously, the injection in step (c) is carried out using a device equipped with an injection nozzle.

Advantageously, the injection nozzle diameter will be such that the speed of the chocolate in the nozzle and the speed downstream are similar (to ± 40%) .

Advantageously, the injection is carried out using a multi-injector: this makes it possible to reduce the diameter (in the case of a round injecting device that makes it possible to obtain strips with a round cross section) of the chocolate strips compared to when a single injecting device is used, for the same proportion of chocolate, and therefore to accelerate the ratio of crystallization. Advantageously, the diameter of the strips with a round cross section will be between 2 and 8 mm, advantageously between 4 and 6 mm.

Advantageously, the injecting device used has a rectangular cross section and makes it possible to obtain a chocolate strip with a rectangular cross section, advantageously having a thickness of between 2 and 8 mm, even more advantageously of between 4 and 6 mm (a small thickness allows the chocolate to solidify more quickly) .

Advantageously, in order to prevent blocking of the

injection nozzle, which is cooled by the stream of cold acidic milk base, it will be insulated or insulating (for example made of Teflon ) or heated (advantageously to a temperature of between 40 and 55 0 C, advantageously to a temperature of 5O 0 C) , advantageously using a double-walled jacket: this will not detemper the chocolate, since the time taken to pass through it is short.

Advantageously, the injecting device in step (c) is placed at the center of the tube.

Advantageously, the entry of water into the device for implementing steps (a) and (b) and optional steps (α) and

(al) will be avoided under all circumstances, using a device equipped with a nonreturn valve, just before the injecting device in step (c) .

Thus, in a particular embodiment of the invention, the method according to the invention is carried out in a device that has a nonreturn valve in order to separate the stream of chocolate obtained in step (b) from the stream of acidic milk base.

In the context of the present invention, step (d) of the method according to the present invention consists of the solidification of the injected, pasteurized chocolate.

This solidification is due to the contact of the chocolate with the cold acidic milk base (having a temperature between 8 and 16°C, advantageously between 8 and 12 0 C, and advantageously between 8 and 10 0 C) .

Advantageously, the device for implementing step (d) consists of a portion of linear pipework of equal diameter, with no pipe failures.

Advantageously, this device is equipped with a double- walled jacket so as to improve heat transfer (the water circulating in the double-walled jacket has a temperature between 1°C and the temperature of the acidic milk base, advantageously the water circulating in the double-walled jacket has a temperature of 1°C) . In this case, this device makes it possible to cool the acidic milk base + chocolate strip combination.

In order for the chocolate to solidify, it must be cooled to less than 16 0 C, preferably to less than 14°C, preferably to less than 12 0 C, before step (e) of the method according to the present invention. If the chocolate is insufficiently solidified at the time of step (e) of the method according to the present invention, it will still be elastic at the center and the device for implementing step (e) will have to apply greater shear and will therefore be more destructive with respect to the texture of the acidic milk base. In addition, chocolate will, in general, be less water resistant .

Advantageously, the solidification time in step (d) is between 50 and 600 s, preferably from 150 to 300 s.

Advantageously, the device for implementing step (d) of the method according to the present invention is equipped with a length of pipework that is sufficient to ensure the solidification time of the chocolate. Advantageously, this length is at least 5 m. This pipework can be placed vertically in order to limit the impact of movement linked to Archimedes pressure in the event of the machine stopping.

When the industrial flow rates are too high, the pipe length or diameter required to ensure the solidification

time of the chocolate may be too great. In this case, the method according to the present invention advantageously comprises an intermediate step (dl) , between steps (d) and (e) , consisting of intermediate storage, with stirring, of the fresh milk product/"solid" (still "elastic") chocolate ribbon mixture, advantageously in a stirred buffer tank, where the crystallization continues so as to finally obtain a really hard chocolate.

In the context of the present invention, step (e) of the method consists in cutting the pasteurized, solidified chocolate into pieces and optionally mixing it into the acidic milk base by means of a dynamic mill.

Advantageously, the dynamic mill is chosen from the group consisting of rotary blades, propellers, centrifugal pumps, worms, endless screws, gear pumps, the Dosys mixer, rod boxes (rods with a square cross section) , simple rotors (cross, centrifugal pump type) with no screen or rotors/stators with screen (for example: Silverson 275) ; advantageously, in this case, the stator has large openings so as to prevent blockages .

Advantageously, the dynamic mill provides a low rotation speed (m/s) which causes less destructuring of the milk base (for example: worm + counter blade) .

Advantageously, the dynamic mill is equipped with a counter blade.

The counter blade serves as a support and makes it possible to cut the chocolate with a lower rotation speed. The regulatable rotation speed makes it possible to adjust the size of the chocolate pieces. Advantageously, the dynamic mill is a rotor/stator with screen or a simple rotor (cross, centrifugal pump type)

without screen + counter blade (the chocolate ribbon is held by the counter blade at the cutting point) . This allows better control of the maximum size of the chocolate pieces, thus making it possible to prevent blocking of the metering device downstream.

Advantageously, the longest dimension of the chocolate pieces obtained in step (e) is between 1 and 6 mm, advantageously between 4 and 10 mm, advantageously between 4 and 6 mm.

In a particular embodiment of the invention, step (e) also comprises the addition and the mixing into the milk base of other ingredients, advantageously chosen from sweetened syrups, cream, fruit preparations or preparations containing cocoa. Their temperature will have to be adjusted so as not to cause the chocolate pieces to melt. Their maximum acceptable temperature depends on the percentage injected and on the rapidity of mixing; however, advantageously, their temperature will be less than 30 0 C, advantageously between 4 and 20 0 C.

In the context of the present invention, step (f) of the method consists of the recovery of an acidic fresh milk product containing pieces of pasteurized chocolate having a fat concentration of between 46 and 85% by weight, said product being conserved at a temperature of between 1 and 10 0 C for a period of between 12 days and 6 weeks.

Advantageously, the milk product obtained comprises no additive or preserving agent. Advantageously, it contains no alcohol .

Advantageously, the milk product obtained in step (f) contains between 0.5 and 10% by weight of chocolate pieces relative to the total weight of the milk product,

advantageously between 4.5 and 10% by weight, advantageously between 2.5 and 5% by weight.

In particular, the milk product obtained may have the composition indicated in table 7 below:

Table 7: % composition, by weight, of a milk product obtained by means of the method according to the present invention

In a particular embodiment of the invention, a large amount of chocolate is injected in step (c) in proportion to the acidic milk base (advantageously between 50% and 95% by weight of chocolate, advantageously between 65 and 90% by weight of chocolate, even more advantageously between 75 and 85% by weight of chocolate, the remainder consisting of the acidic milk base) and the rest of the acidic milk base is added in step (e) so as to obtain, during step (f) , an acidic fresh milk product containing the desired amount of chocolate pieces.

The advantages of this particular embodiment comprising the use of a large amount of chocolate, in particular in the versions containing between 75 and 90% by weight of chocolate, are as follows: • the proximity of the double-walled jacket allows good heat transfer,

• the chocolate is "guided" in the tube, hence fewer risks of blocking associated with entangling of chocolate strips, • since the chocolate strip is virtually wedged against the wall of the crystallization tube (33) , the end of the tube (33) , which opens into the cutting means, supports the strip and acts as a counter blade (41) .

Thus in this variant, the wall of the crystallization pipe (33) may itself act as a counter blade (41) :

In a particular embodiment of the invention, the method according to the present invention comprises an additional step (g) consisting of the metering of the product obtained in step (f) into a thermoformed or preformed decontaminated pot. The pot is therefore thermoformed just before filling, or is a preformed and decontaminated pot.

A cover is then placed on the pot. This entire step (g) takes place in an environment in which the microorganisms are filtered out, advantageously under a laminar flow hood that delivers sterile air under slightly reduced pressure, as conventionally in the fresh milk products industry.

In a particular embodiment of the invention, the method according to the present invention comprises an intermediate step (fl) consisting of buffer storage of

the product obtained in step (f) , advantageously in a small buffer tank.

In a particular embodiment of the invention, the method according to the present invention comprises an additional step (h) consisting of optional cooling to a temperature of between 1 and 10 0 C, and of storage at a temperature of between 1 and 10 0 C, of the fresh milk product .

The present invention also relates to an acidic fresh milk product containing chocolate pieces, which contains between 4.5% and 10% by weight of chocolate, relative to the total weight of the milk product, wherein the chocolate is pasteurized and has a fat content of between 46 and 85% by weight, and wherein the acidic fresh milk product containing chocolate pieces is conserved at a temperature between 1 and 10 0 C for a period of between 12 days and 6 weeks.

Advantageously, the product according to the present invention can be obtained by means of the method according to the present invention and as described above.

Advantageously, the chocolate contained in the product according to the present invention has the characteristics indicated above in the context of the method according to the present invention.

Advantageously, the same is true for the acidic fresh milk product excluding chocolate pieces.

Advantageously, the longest dimension of the chocolate pieces contained in the product according to the present invention is between 1 and 6 mm, advantageously between 4

and 10 mm, advantageously between 4 and 6 mm.

Advantageously, the chocolate pieces are dispersed homogeneously in the acidic fresh milk product according to the present invention.

Advantageously, the product according to the present invention contains neither additive, nor preserving agent, nor alcohol.

The present invention also relates to a multilayer fresh food product comprising at least one layer of product according to the present invention.

The present invention also relates to a device for implementing the method according to the present invention. This device comprises a means for pasteurization (10) of the chocolate, a means for cooling

(20) of the pasteurized chocolate, a means for continuous-stream injection (32) of the cooled pasteurized chocolate, an inlet (30, 31) for the stream of pasteurized acidic milk base, a dynamic mill (36) for the solidified chocolate, and an outlet (37) for the acidic fresh milk product containing pieces of pasteurized chocolate.

Advantageously, the device according to the present invention also comprises a means of metering (38) into a thermoformed or preformed decontaminated pot, advantageously under a laminar flow hood, as conventionally in the fresh milk products industry.

Advantageously, the device according to the present invention also comprises a means of adding (35) and a means of mixing (1) an ingredient other than chocolate.

Advantageously, the mixing means (1) is the dynamic mill

( 36 ) .

Advantageously, the device according to the present invention also comprises a means of storage .-(10) , with stirring, of the pasteurized chocolate.

Advantageously, the device according to the present invention also comprises a means of preparation (8) of the chocolate. Advantageously, the same tank (10) is used as a means of preparation of the chocolate, a means of pasteurization of the chocolate and a means of storage of the pasteurized chocolate.

Advantageously, the device according to the present invention also comprises a nonreturn valve (22) between the cooling means (20) and the injecting means (32) .

Advantageously, the dynamic mill (36) of the device according to the present invention is equipped with a deflector/support blade (41) .

The invention will be understood more clearly and the aims, advantages and characteristics thereof will emerge more clearly from the description which follows and which is given with reference to the attached drawings representing nonlimiting examples of implementation of

,the invention, and in which:

Figure 1 represents a first example of a device for implementing steps (a) and (b) and optional steps (α) and (al) of the method according to the present invention, step (a) consisting of a batchwise dry pasteurization.

Figure 2 represents a second example of a device for implementing steps (a) and (b) and optionally steps (α) and (al) of the method according to the present

invention, step (a) consisting of a batchwise dry pasteurization.

Figure 3 represents a device for implementing steps (a) and (b) and optional steps (al) and (α) of the method according to the present invention, step (a) being a continuous dry pasteurization.

Figure 4 represents a device for implementing steps (c) , (d) , (e) , (f) and (g) of the method according to the present invention.

Figure 5 represents a device implementing steps (c) , (d) and (e) of the method according to the present invention.

Figure 6 represents a first example of a device for implementing step (e) of the method according to the present invention.

Figure 7 represents a second example of a device for implementing step (e) of the method according to the present invention.

Figure 8 represents a third example of a device for implementing step (e) of the method according to the present invention.

Figure 9 represents a rod box, i.e. a specific dynamic mill that can be used in the context of the present invention and that appears to be the most suitable for cutting chocolate strips in a rectangular cross section with a width > 7 mm (it is then necessary to cut widthwise and lengthwise) .

-The aim of the device represented in figure 1 is to pasteurize and cool (steps (a) and (b) ) and optionally to

prepare and store (steps (α) and (al) ) the chocolate according to the method of the present invention.

This device comprises an inlet (7) , for the ingredients intended for the preparation of the chocolate, a tank (8) for preparing and storing the unpasteurized chocolate, an outlet (9) for the prepared chocolate, a tank (10) for pasteurization and storage of the chocolate under pressure, mounted on scales (11) , an inlet (12) for sterile nitrogen, a vent (13) allowing the gases to leave, equipped with a valve (14) , an outlet (15) for the pasteurized chocolate, equipped with a valve (16), a pipe A equipped with a pump (17) , with 500 μm filters (18) , with a mass flow meter (19) , and with a heat exchanger (20) (heating of the chocolate during pasteurization, cooling during injection) , a pipe C, a 3-way valve (21) , and a pipe B equipped with a nonreturn valve (22) and with an outlet to the injecting device or the metering device (23) .

The chocolate can be prepared in the tank (8) by addition of the ingredients in bulk via the inlet (7) . This tank

(8) is a stirred tank with a double-walled jacket, mounted on scales (11) , which can also enable storage before pasteurization, for example at 50 0 C. The transfer via the outlet (9) into the pasteurization tank (10) can take place by gravity, overpressure, or , using a pump. Alternatively, the tank (8) does not exist and its preparation takes place directly in the pasteurization tank (10) , the ingredients entering via the pipework (9) .

The pasteurized chocolate remains stored in the pasteurization tank (10) : this avoids a tank having to be pasteurized downstream, and the tank (10) is thus pasteurized at each batch at the same time as the chocolate. Since the chocolate is anhydrous, it is not

necessary to clean between two batches, unless the flavors or colors are incompatible. There is thus no loss of time due to cleaning/pasteurization of the tank (10) . In order to prevent any recontamination, the tank (10) is pressurized by means of a sterile gas source (typically 10 to 30 KPa relative) .

Since the chocolate is incompatible with water, the preferred variant consists in pasteurizing all the pipework (A, C, (9) , (12) , (13) , (15)) dry, in particular at the same time as the pasteurization of the chocolate at each batch, since the circulation, during the pasteurization, in tubes A and C (double-walled jackets with preferably the same heating fluid as the pasteurization tank (10) ) . In order to improve the heat exchange and to limit sedimentation, in particular for chocolates with the high fat content, which are very fluid, these pipes will be either small in diameter relative to the flow rate (as high a rate as possible) , or equipped with static mixers, or with sterile compressed air pumps (for example, 20 s every 10 min in the event of no movement) .

The heat exchanger (20) is optional: it may make it possible to accelerate heat exchanges, in particular when the surface/volume ratio of the tank (10) is unfavorable

(large capacity) . Preferably, it will be of scraped surface type, so as to also be used in cooling

(tempering) in step (b) of the method according to the present invention. An overpressure in the circuit will prevent recontamination via the revolving mechanical fittings.

Then it remains just to pasteurize the pipework B and its accessories downstream of the point X. In a 1st variant, this part B will be as short as possible, if possible

reduced to less than 20 cm in length corresponding to the valve (21) , the nonreturn valve (22) , the pipework B and the outlet to the injecting device/metering device (23) , which will preferably also be pasteurized dry (double- walled jacket at 100°C/10 to 20 min, after cleaning or without cleaning.

The nonreturn valve (22) prevents the chocolate (anhydrous) from being contaminated with the water from the acidic milk base in the event of reverse pressure.

Alternatively, the pipework B downstream of the point X can also be pasteurized conventionally by cleaning in place, and then pasteurization with hot water or steam: however, it is necessary to eliminate the water and preferably to dry the installation before sending the chocolate thereto (stream of sterile gas, or vacuum, heated with double-walled jacket, for example filled with steam at 110 KPa in absolute pressure.

Alternatively, the valve (16) can remain closed during the pasteurization and the return C is then nonexistent: it is then necessary to clean/ sterilize/dry the entire installation downstream of the point S, conventionally as indicated above.

Other dry sterilization techniques exist, for example with hot fat (100°C/10 min) .

The double-walled jacket of the pipework C will advantageously be at a minimum temperature of 4O 0 C, so as to prevent crystallization in the pipe, especially when the metering is carried out at a temperature ≤35°C. The valve (21) (3-way) closes the pipework C when the chocolate is injected into the fresh milk product: this makes it possible to determine the flow rate injected via

the flow meter (19) . Preferably, the pump (17) is controlled by the flow rate indicated by the flow meter (19) .

Ideally, the tank (10) is on scales (11) so as to facilitate the management of the ingredients, in particular the use of pasteurized chocolate. Alternatively, level detectors (capacities, vibrating bimetal, etc.) will perform the same function. All the pipework (A, B, C, (9) , (13) , (15) , (7) , (12)) /tanks ((10) , (8))/, accessories for chocolate have a double- walled water jacket (preferred variant) , or even have trace heating using strip electrical resistors (less well regulated) .

The flow rate of chocolate should be even when injected.

The device in figure 2 comprises a pasteurization and storage tank (10) which is not pressurized, mounted on scales (11) , an inlet (9) for the ingredients for producing the chocolate, a permanent vent (12) equipped with a sterile filter (24) , an outlet (15) for the pasteurized chocolate, equipped with a valve (16) , a pipe A equipped with a pump (17) , with 500 μm filters (18) , with a mass flow meter (19) , and with a heat exchanger (20) , a pipe C, a 3-way valve (21) , and a pipe B equipped with a nonreturn valve (22) and with an outlet (23) to the injecting device and the metering device.

The tank (10) is not pressurized (and therefore less expensive) , and has been constructed with respect to less strict standards in terms of hygiene than the tank in figure 1. It is connected to ambient air via a sterile filter (24) that acts as a vent (12) to eliminate the steam. After pasteurization, the chocolate is stored at 70-75 0 C without overpressure (this kills any possible

recontaminants) and is then cooled on line before injection, with 2 variants:

• cooling to 31-40 0 C (double-walled water jacket at 28-39°C) , preferably 35-38 0 C, by means of any exchanger (20) (tubular or scraped surface, or even plates) ;

• cooling of the chocolate to 24-31°C by means of a scraped surface exchanger (20) (preferred variant, since the temperature is lower, and crystallization is therefore more rapid) .

The pipework A between the point S and the heat exchanger (20) and C will also be maintained at 70°C-75°C for microbiological reasons (no recontamination in the event of a leak in the pump (17) ) .

The scales (11) are optional and can be replaced with off-line weighing out, or else flow meters. The 500 μm filters (18) and the flow meter (19) are optional.

In figures 1 and 2, it is possible to store the pasteurized chocolate in an intermediate buffer tank placed between the valve (16) and the heat exchanger (20) (failing this, the point X) : if the storage is carried out at less than 75°C, it will then have to be pasteurized during the 1st use and at each loss of the pasteurized state (since the chocolate is virtually anhydrous, no microbial growth can take place, except in an exceptional case: maintenance, etc.) . This may be carried out conventionally (cleaning, then hot water sanitization, then evaporation) , or preferably by heating, providing an Fz > 6000 min (for example, 22 h at 75°C) , preferably Fz > 20 000 min.

It is also possible to permanently store the chocolate from this tank at 75 0 C so as to have "continuous"

pasteurization.

Figure 3 represents a device comprising a tank (8) for preparation and storage of the unpasteurized chocolate, mounted on scales (11) , an inlet (7) for the ingredients for preparing the chocolate, an outlet (9) for the unpasteurized prepared chocolate, equipped with a valve

(16) , a pipe A equipped with a pump (17) , with a mass flow meter (19), with 500 μm filters (18) , with a heat exchanger for the heating and the pasteurization (25) , and with a heat exchanger for the cooling (20) , a pipe C equipped with a nonreturn valve (26) , a 3-way valve (21) and a pipe B equipped with a nonreturn valve (22) and with an outlet to the injecting device or the metering device (23) . When the device is run, the part between the pasteurizing device (heat exchanger (25) ) and the nonreturn valve (26) of the pipe C is pasteurized by- heating the entire conduit at 100°C/20 min. Only then is the cooling device (heat exchanger (20) ) turned on and the valve (16) opened in order to use the chocolate. If the injection is stopped for a few minutes, the chocolate is recycled via the pipework C, the double-wall jacket of which is at 50 0 C. Alternatively, a buffer tank at 7O 0 C + delivery pump can be added before the heat exchanger intended for the cooling (20) . The part of the pipework C downstream of the nonreturn valve (26) is considered to be unpasteurized. Furthermore, in this device, it is advisable to take precautions in the pipework using agitation due to the speed, air or static mixers. Ideally, the pipework C, which is not always fed, will be sloping so as to self-empty, or will be equipped with static mixers.

Figure 4 describes a device for implementing the method according to the present invention, which comprises a tank for pasteurization and then storage of the chocolate

at a temperature of 28 to 32 0 C (27), an outlet (28) for the chocolate, an inlet (29) for the milk base, that splits into 2 ((30) , (31)) , an injecting device (32) , a device for cooling the chocolate (33) , a . syrup storage tank (34) , an inlet for the syrup (35) , a dynamic mill (36) , an outlet for the mill (37) , and a metering device (38) . The inlet (29) for the milk base is separated into two parts (30 and 31) which come together again to form a single part so as to allow the injection of the chocolate in the center of the combination of the two parts (32) .

The injection of the syrup is carried out before the entry into the dynamic mill (36) so as not to affect the solidification of the chocolate. The dynamic mill (36) is used to cut the solidified chocolate into pieces while at the same time mixing the syrup and the milk base with the chocolate. The metering device is a Trepko machine (38) .

The arrows used in this scheme indicate the direction of circulation of the streams of milk base, of chocolate and of syrup. In the interests of simplicity, the chocolate return loop from the injecting device to the storage tank is not drawn. However, it is necessary in order to avoid sedimentation and/or solidification of the chocolate.

Figure 5 describes a device for injecting the chocolate into the milk base. It comprises the inlets (30 and 31) for the acidic milk base, the inlet (28) for the chocolate, a nonreturn valve (22) , a device (32) for injecting the chocolate, a device (33) for solidifying the chocolate, a dynamic mill (36) and an outlet (37) for the milk product containing chocolate pieces.

The nonreturn valve (22) prevents entry of the water into the pasteurized chocolate under any circumstances. It is located just before the injecting device (32) .

The inlet for the milk base is in two parts (30 and 31) which are then combined into a single line so as to inject the chocolate at the center of this coming together. The device (33) for solidifying the chocolate consists of a tube that has a double-walled jacket containing water at a temperature of between 1 and 4 0 C. The dynamic mill (36) used in this device is a worm. The arrows used in the scheme indicate the direction of circulation of the streams of milk base and of the product containing the chocolate pieces.

Figure 6 represents an enlargement of the dynamic mill device (36) in figure 5, which, in this case, consists of a worm. Moreover, this device also comprises a deflector/support blade (41) just before the inlet for the stream consisting of the milk base (40) and the solidified chocolate strip (39) into the dynamic mill (36) .

The arrows used in this scheme indicate the direction of circulation of the streams of milk base (40) + solidified chocolate strip (39) and of the product containing the chocolate pieces.

Figure 7 represents a device similar to that of figure 6, except that the dynamic mill (36) consists of rotary blades .

Figure 8 represents a device similar to that of figures 6 and 7, except that the dynamic mill (36) consists of a propeller and that the deflector/support blade (41) has holes in it so as to allow the milk base (40) to pass through.

The following examples " are given by way of nonlimiting

indication.

Example 1

The chocolate (formula 1 in table 3) is produced, pasteurized, cooled and stored in the same 1000 1 tank equipped with a double-walled jacket and with a stirrer that scrapes the walls (batch) (figure 1) .

The initial natural mold and yeast contamination of the chocolate is 40 cfu/g.

The chocolate is prepared as follows:

Blocks of 25 kg of solid cocoa butter (20 0 C) are melted in the closed tank (10) , the double-walled jacket being supplied with steam at 100-110 0 C so as to accelerate the melting. Once said cocoa butter is molten, the other solid ingredients (chocolate, cocoa paste) , purchased as "easy melt" (chips, or pieces typically of 1 to 30 g) , are melted into the cocoa butter at approximately 100 0 C and the double-walled jacket is regulated at 75°C. Once all the ingredients are molten, the stirring (maximum) is then started out in order to homogenize the chocolate and prevent settling out. The cocoa powder is then dispersed in the chocolate to complete the recipe.

The tank (10) is closed, the pump (17) starts up so as to provide circulation in the pipeworks A and C, and the chocolate, subjected to maximum stirring, is brought to

100 0 C by heating via the double-walled jacket supplied with steam (vapor pressure 110 KPa in absolute pressure) .

When a temperature of 100 0 C is reached at all points

(tank (10) and outlet pipework C) , it is maintained for 5 minutes (F z = 41 700 min) , then the tank (10) is opened to the air by means of a vent (13) via a sterile filter

so as to eliminate the steam.

The tank (10) is then closed again and is placed under a nitrogen pressure (12) via a sterile filter, the pressure being regulated at 120 KPa in absolute pressure until the production of the next batch, so as to prevent any entry of gas or of material from the outside which could recontaminate the pasteurized product.

The chocolate is then immediately cooled to 33 0 C by regulating the water inlet in the double-walled jacket, and is maintained at 33 0 C until use (within 24 h) .

The taste of the chocolate has not been substantially modified by the pasteurization.

The residual contamination thereof is less than 1 cfu per 30 g (except for bacterial spores) , i.e. a reduction of more than 3 log.

The method for counting yeast + molds in the chocolate ("25°C/5+5" method) is as follows:

The yeast and mold contamination is counted by diluting the chocolate to 1/lOth in a conventional "malt extract" medium (mixture at 4O 0 C so that the chocolate is clearly fluid) , and then enriching (the molds/yeast initially present) at 25°C/5 days with agitation (molds are aerobic) . At the end of this, 1 ml is taken and deposited on a "malt extract agar" medium and incubated at 25°C/5 days. The presence or absence of contaminant (yeasts/molds) is then noted.

The chocolate is cooled by means of a scraped surface exchanger (20) , and is injected at 26 0 C into a sweetened yoghurt at 8 0 C in a tube with a device represented in figure 5, via a 5 x 30 rectangular nozzle insulated by

means of a double-walled jacket at 28 0 C. The % composition, by weight, of the sweetened yoghurt is as follows :

Skimmed milk powder: 2.1% Sugar 8%

Gelatin 0.4%

Lactic ferment Milk containing 0% fat 89.6%

The speeds for the yoghurt and for the chocolate are identical and equal to 3.7 m/min. The double-walled jacket of the tube is supplied with water at PC. The crystallization time is 194 s. The mill is a rod box (figure 9) .

1050 kg/h of sweetened yoghurt containing 3.25% by weight of chocolate pieces are thus obtained.

Example 2

The chocolate (formula 2 in table 3) is produced, pasteurized, cooled and stored in the same 400 1 tank (10) equipped with a double-walled jacket and a stirrer that scrapes the walls (batch) (figure 1 without heat exchanger or flow meter) .

The initial contamination thereof was not determined.

The chocolate is prepared in the following way:

Blocks of 25 kg of solid cocoa butter, the cocoa paste and the chocolate are melted in the closed tank (10) , the double-walled jacket being supplied with water at 75°C. Once all the ingredients are molten, the stirring is started in order to homogenize the chocolate and prevent

settling out .

The chocolate is pasteurized at 100°C/5 min, and then cooled to 28-3O 0 C (double-walled jacket with water at 25 0 C) . The total cycle time is 1 h 15 min.

The taste of the chocolate has not been substantially- modified by the pasteurization.

The entire plant up to the injecting device was pasteurized at the same time as the product. The valve (21) and the injecting device are dry-pasteurized by circulating steam for 20 min at 100 0 C in their double- walled jackets.

The chocolate is injected at 28-30 0 C into a yoghurt at 10 0 C (pH 4.4, Dornic acidity 110, (the number of Dornic degrees = number of ml of NaOH solution at the concentration N/9 required to neutralize 10 ml of milk: 1° Dornic corresponds to 0.01% of lactic acid), viscosity at 10 0 C of between 956 and 1300 mPa. s measured after 10 s in a Rheomat spin 2, cylinder 2 Interval 64 RPM) via an injecting device according to figure 5.

The yoghurt used has the composition indicated in table 8 below:

Table 8: % composition, by weight, of the yoghurt

Ingredients %

Skimmed milk containing 0.5 g/1 of fat 54 .73

Cream containing 400 g/1 of fat 14 .72

Skimmed milk powder 6. 59

Sugar 8

Water 15 .67

Gelatin 250°Bloom 0. 25

Yoghurt ferments 0. 02

It has the characteristics given in table 9 below:

Table 9: Characteristics of the yoghurt as % by weight

The chocolate is pumped by a PCM positive displacement pump at a flow rate of 175 kg/hour, but only part is injected, the rest being recycled (so as to prevent sedimentation and solidification in the pipes during stoppages) . At this stage, 2.6% of chocolate is injected into 97.4% of the yoghurt (by weight) .

The injecting device is composed of 3 nozzles, 3.5 mm in diameter, arranged at 120°. The cooling pipework is 8.2 meters long (passage time and therefore cooling time 90 seconds) . It is equipped with a double-walled jacket at 2 ± 1°C. In this cooling pipework, 3 cylinders of chocolate, 3.6 mm in diameter, are obtained.

The Dosys ® Dosymix dynamic mixer receives 95% by weight of the mixture of yoghurt + chocolate strips + 5% of a sweetened preparation: it breaks the chocolate and ensures mixing of the entire combination.

The average size of the chocolate pieces obtained is < 8 mm.

The metering is provided by ultra-clean thermoforming machines that are conventional for yoghurts.

The microbiology is evaluated on the finished products in the following way: incubation of a pot for 24 h/30°C, and then

conventional counting of molds/yeasts in 1 g, incubation of 30 pots of 125 g for 7 days/25°C, and then organoleptic evaluation of the absence of .contamination (visual, odor, swelling of the pots, etc. ) .

No molds or yeasts were demonstrated.

Example 3

The yoghurt used has the same composition and the same characteristics as that of example 2 above (tables 8 and 9) .

The composition of the chocolate is that of table 3 formula 2.

The conditions of the method for pasteurizing the chocolate are as follows: Preheating temperature: 75 0 C ± 2 0 C in order to melt the chocolate and the cocoa butter.

Pasteurization temperature: 100 0 C ± 2 0 C.

Temperature hold: 5 minutes at 100 0 C.

Cooling temperature: 28 to 30 0 C and maintenance at this temperature.

The device used for implementing the method is that of figure 4.

The yoghurt pipe (29) is split into two parts ( (30) , (31) ), 5 cm (2 inches) in diameter, that come together again as a single part, 7.62 cm (3 inches) in diameter, so as to allow the injection of the chocolate at the center of the combination. The flow rate of the yoghurt is 1500 kg/hour. The temperature of the yoghurt is 1O 0 C.

The chocolate is pumped by a PCM positive displacement pump at a flow rate of 175 kg/hour, with a pipe (28) diameter of 12.7 mm (1/2 inch), but only 40.5 kg/H are injected, the rest being recycled (to prevent sedimentation and solidification in the pipes during stoppages) . The injection of these 40.5 kg/H is carried out at between 28 and 29 0 C via 3 nozzles, 3.5 mm in diameter. At this stage, there is 2.6% by weight of chocolate.

After injection of the chocolate, the pipe (33) 8.2 m in length has a double-walled jacket in order to solidify the chocolate. The temperature of the water in the double-walled jacket is 2°C. The time spent therein is 90 s. Sweetened syrup having a solids content of 60% and at a pH of 4 is then added (35) . The flow rate of the syrup is 90 kg/hour. The injection of the syrup is carried out before (35) the entry into the dynamic mill (36) with the aim of not affecting the solidification of the chocolate. The dynamic mill (36) is used to cut the solidified chocolate strip into pieces while at the same time mixing the syrup and the chocolate pieces with the yoghurt. This dynamic mill (36) is a Dosys ® DM 2000. Finally, the product, containing 2.5% by weight of chocolate pieces, is metered using a Trepko machine (38) .

Example 4

The method is identical to that of example 2, except for the following differences:

The analytical composition of the chocolate is as follows :

50% by weight of fat, 30% by weight of sugar, 20% by weight of dry defatted cocoa. This molten chocolate is artificially contaminated with lyophilized Aspergillus

niger spores.

The pasteurization is carried out continuously at 180 kg/h on a scraped surface heat exchanger (25) , followed by maintenance at 102°C/1.3 min (F Z70° c 19 813 min) (device in figure 3) .

Result: >5.3 log reduction in Aspergillus niger spores.

Example 5

The method is identical to that of example 2, except for the following differences:

The analytical composition of the chocolate is as follows: 70% by weight of fat, 20% by weight of sugar, 10% by weight of dry defatted cocoa.

The pasteurization is carried out in the following way: 1 min/lO5°C (F 2 = 37 600 min) or 5 min at 100 0 C (F z = 41 700 min) .

The initial contamination is 35 molds + yeasts/g. The final contamination is as follows: absence of molds and of yeasts in 1000 g (counting with the "25°C/5+5" method indicated above in example 1: 10 bottles of 100 g of chocolate + 900 g of broth) .

Example 6

The method is identical to that of example 2, except for the following differences:

300 kg of chocolate (formula 2 table 3) are produced, pasteurized and stored in the same 500 1 tank (10) equipped with a double-walled jacket and a stirrer that scrapes the walls (batch) (figure 2) . The initial natural contamination of the chocolate in terms of molds and yeasts is 45 cfu/g.

The chocolate is prepared according to the steps below:

Blocks of 25 kg of solid cocoa butter (20 0 C) are melted in the closed tank (10), the double-walled jacket being supplied with steam at 100-110 0 C so as to accelerate the melting. Once this is molten, the other solid ingredients

(choqolate, cocoa paste) , purchased as "easy melt"

(chips, or pieces typically of 1 to 30 g) , are melted in the cocoa butter at approximately 100 0 C and the double- walled jacket is regulated at 75°C. Once all the ingredients are molten, the stirring (maximum) is then started so as to homogenize the chocolate and prevent settling out.

The tank (10) is closed, the pump (17) starts up so as to provide circulation in the pipework A and C, and the chocolate, subjected to maximum stirring, is brought to 100 0 C by heating via the double-walled jackets supplied with steam (steam pressure 120 KPa in absolute pressure) . When the temperature of 100 0 C is reached at all points

(tank (10) and outlet pipework C) , it is maintained for

10 minutes. The tank (10) is permanently open to the air by means of a vent (12) via a sterile filter (24) . The chocolate, the tank (10) and the pipes up to the point X are then pasteurized. The chocolate is then cooled and maintained at 70 0 C by regulating the water inlet in the double-walled jacket. The taste of the chocolate has not been substantially modified by the.pasteurization.

The residual contamination of the chocolate is less than 1 cfu per 100 g ("25°C/5+5" method indicated in example 1: absence of molds/yeasts in 100 g) .

The chocolate is then cooled to 26 0 C by means of a scraped surface heat exchanger (20) located just before the injecting device, and then injected (round nozzle,

6 mm in diameter, according to the device in figure 5) into a sweetened and flavored yoghurt (the composition and the characteristics of which are those indicated in example 2: tables 8 and 9, with the exception of the addition of 0.2% by weight of flavoring to the composition of the yoghurt) , cooled beforehand to 8 0 C. 2.5% of chocolate is injected via 1 nozzle, which forms a cylinder 6.1 mm in diameter. Solidification takes place in a linear pipe with a double-walled jacket at 1°C. The solidification time is 300 s in a 20-meter tube. After solidification and cooling of the chocolate to a temperature of < 12°C, the chocolate ribbon is milled by means of an endless screw (dynamic mill (36) ) . The chocolate pieces have an average length of < 8 mm. The product is stored in a buffer tank and metered into thermoformed pots (38) using an ultra-clean machine (under a laminar flow hood) , before storage at a maximum of 10 0 C for 30 days.

Example 7

The method is identical to that of example 1, except for the following differences:

The composition of the chocolate is given in table 10 below:

Table 10: % com os!tion, by wei ht, of the chocolate

In these formulae :

- the cocoa mass contains, as % by weight: 1.7% of water, 53.4% of fat and 44.95% of dried defatted cocoa; the water content thereof is <1%, the particle size thereof is fine (minimum of 90% of particles < 20 μm; maximum of 0.2% of particles > 75 μm) ;

- the dark chocolate contains, as % by weight: 0.5% of water, 27.7% of fat (of which approximately 0.3% lecithin) , 22.3% of dried defatted cocoa and 49.5% of sugar; advantageously, its particle size using a Palmer is < 30 μm.

Advantageously, these two constituents and the cocoa butter are sold by the company Barry-Callebaut.

The initial natural mold and yeast contamination of this chocolate is 75 cfu/g.

The preparation of the chocolate is identical to example 1, except that there is no cocoa powder. The chocolate is then pasteurized and cooled as in example 1. The residual contamination (excluding bacterial spores) , measured by the same method as in example 1, is less than 1 cfu/30 g.

The chocolate is cooled on line to 26°C on a scraped surface heat exchanger, and is then injected into the sweetened yoghurt (same formula as example 1) at 10 0 C, via a 6.5 mm nozzle, in a crystallization tube that has a double-walled jacket and an internal diameter of 8 mm. The double-walled jacket is supplied with ice-cold water at 1°C. At this stage, there is 75% by weight of chocolate and 25% by weight of yoghurt.

A cylinder of chocolate 6.9 mm in diameter is formed at the center of a ring of yoghurt, and the time taken to pass through the crystallization tube is 181 s, for a chocolate flow rate of 6 kg/h. Just at the outlet of the crystallization tube, the cylinder of solidified chocolate is cut by the shearing of the blades of a centrifugal pump used as a dynamic mill. The speed of rotation is adjusted so as to obtain chocolate "cylinders" that are approximately 8 mm long.

Additional yoghurt at 4 0 C reaches the centrifugal pump, at a flow rate of 300 kg/h, and mixes with the chocolate pieces, which gives a sweetened yoghurt containing 2% by weight of chocolate pieces.

The mixture spends 6 min in a stirred buffer tank, and is then metered into 250 g preformed decontaminated pots under a laminar flow hood, and a cover is then placed on the pots. They are conserved at between 2 and 1O 0 C for 30 days, both from a microbiological point of view and an organoleptic point of view (maintenance of the crunchiness of the chocolate) .

In order to increase the flow rate of the line, it is sufficient to place several crystallization tubes in parallel. For example, a flow rate of 900 kg/h of yoghurt

could be mixed in the centrifugal pump with the solidified chocolate originating from 3 crystallization tubes, each at 6 kg/h.