阅读说明：本技术 一种抗霜巧克力及其制备方法 (Anti-frost chocolate and preparation method thereof ) 是由 黄强 邵苗 张斌 扶雄 于 2020-12-09 设计创作，主要内容包括：本发明公开了一种抗霜巧克力及其制备方法。本发明的抗霜巧克力中添加有聚甘油蓖麻醇酸酯-多孔淀粉复合物,其制备方法包括以下步骤：1)将可可脂熔化,得到液态可可脂；2)将蔗糖粉碎,过筛,得到蔗糖粉；3)将可可粉、乳粉和蔗糖粉加入液态可可脂中,加热混合,精磨,得到巧克力浆料；4)将聚甘油蓖麻醇酸酯-多孔淀粉复合物加入巧克力浆料中,混合,浇注成型,冷却脱模,即得抗霜巧克力。本发明的抗霜巧克力具有优异的抗霜性能,解决了巧克力在高温运输、储存过程中的品质下降问题,提高了产品的货架期。(The invention discloses frost-resistant chocolate and a preparation method thereof. The preparation method of the frost-resistant chocolate added with the polyglycerol ricinoleate-porous starch compound comprises the following steps: 1) melting cocoa butter to obtain liquid cocoa butter; 2) crushing and sieving sucrose to obtain sucrose powder; 3) adding cocoa powder, milk powder and sucrose powder into liquid cocoa butter, heating, mixing, and fine grinding to obtain chocolate slurry; 4) and adding the polyglycerol polyricinoleate-porous starch compound into the chocolate paste, mixing, casting and molding, cooling and demolding to obtain the frost-resistant chocolate. The frost-resistant chocolate has excellent frost resistance, solves the problem of quality reduction of chocolate in the processes of high-temperature transportation and storage, and improves the shelf life of products.)

1. A polyglycerol ricinoleate-porous starch compound is characterized in that: the composition of the polyglycerol ricinoleate-porous starch composite comprises porous starch, polyglycerol ricinoleate loaded in porous starch pore channels and cocoa butter loaded in porous starch pore channels.

2. The method for preparing polyglycerol polyricinoleate-porous starch composite according to claim 1, comprising the steps of: firstly, mixing polyglycerol ricinoleate and cocoa butter to prepare a mixed solution, adding porous starch into the mixed solution for loading, and finally removing the mixed solution which does not participate in loading to obtain the polyglycerol ricinoleate-porous starch compound.

3. The method for preparing polyglycerol ricinoleate-porous starch composite according to claim 2, wherein: the mass ratio of the polyglycerol ricinoleate to the cocoa butter is 1-3: 80-90; the mass ratio of the porous starch to the mixed liquid is 6-8: 1-2.

4. An anti-bloom chocolate characterized by: the frost-resistant chocolate to which the polyglycerol ricinoleate-porous starch complex according to claim 1 is added.

5. The frost-resistant chocolate according to claim 4, comprising the following components in parts by mass:

cocoa butter: 30-36 parts of a solvent;

cocoa powder: 9-12 parts;

milk powder: 23-26 parts;

sucrose: 30-33 parts;

the polyglycerol ricinoleate-porous starch complex of claim 1: 0.9 to 9 portions.

6. The method of making a frost-resistant chocolate according to claim 5 comprising the steps of:

1) melting cocoa butter to obtain liquid cocoa butter;

2) crushing and sieving sucrose to obtain sucrose powder;

3) adding cocoa powder, milk powder and sucrose powder into liquid cocoa butter, heating, mixing, and fine grinding to obtain chocolate slurry;

4) and adding the polyglycerol polyricinoleate-porous starch compound into the chocolate paste, mixing, casting and molding, cooling and demolding to obtain the frost-resistant chocolate.

7. The method of preparing a frost-resistant chocolate according to claim 6, wherein: the melting in step 1) is carried out at 40-45 ℃.

8. The method of preparing a frost-resistant chocolate according to claim 6, wherein: and 3) heating and mixing at 40-45 ℃ for 2-3 h.

9. A method of preparing a frost-resistant chocolate according to any of claims 6 to 8 wherein: and 3) performing fine grinding at 40-45 ℃ for 15-20 h.

10. A method of preparing a frost-resistant chocolate according to any of claims 6 to 8 wherein: the average particle size of the solid matters in the chocolate mass in the step 3) is 20-25 μm.

Technical Field

The invention relates to the technical field of food processing, and particularly relates to anti-frost chocolate and a preparation method thereof.

Background

Chocolate is a leisure food and is mainly processed by cocoa butter, cocoa powder, a sweetening agent, milk powder and the like. The cocoa butter in chocolate is a continuous phase and is used for endowing the chocolate with a network structure for maintaining the space position of a dispersed phase, determining physical properties such as microstructure, texture, crystallization property, rheological property and the like of the chocolate, and simultaneously determining the appearance, shelf life and sensory attributes of a chocolate product in a macroscopic view. Cocoa powder, sweeteners and other added components are in the dispersed phase and may to some extent affect the continuous phase spatial network structure of the chocolate. Cocoa butter has a melting point of about 33 ℃ and exhibits excellent solubility in the oral cavity, and melts completely when the temperature exceeds 35 ℃. During transportation of traditional chocolate in hot seasons, transformation of cocoa butter crystal form and oil migration often occur due to temperature change, so that the surface of chocolate is covered by light-colored or white cream, and the phenomenon is called blooming. The problem of blooming is the main quality problem in the process of chocolate circulation, and accounts for more than 70 percent of the quality problem of chocolate, so that the improvement of the anti-blooming performance of the chocolate is of great significance for improving the sensory attribute and solving the problem of quality reduction in the processes of storage and transportation.

Chocolate bloom is divided into two categories: sugar creams and fat creams. Generally speaking, frosting occurs at a low rate and in a small proportion affecting the quality of the chocolate, and can be avoided by controlling the humidity during processing and storage. Fat bloom occurs at a high rate and has a great influence on the quality of chocolate, and its formation is closely related to the fats and oils (including cocoa butter and cocoa butter substitutes) used in chocolate. At present, it is generally believed that the reasons for chocolate bloom are: 1) the cocoa butter crystals are transformed from form V to form VI; 2) the fat in the center of the chocolate migrates to the outer layer. Therefore, the key to inhibiting chocolate bloom is to bind, stabilize the fats and oils therein, and reduce the crystal transformation of cocoa butter crystals and the migration of fats and oils.

In recent years, there has been much research on mitigating chocolate bloom, and the main means include: strengthening the space network structure of chocolate, adding bound grease polymer and increasing the melting point of grease.

US 4446166 discloses a chocolate composition for the preparation of heat resistant chocolate products and a process for its preparation, wherein the spatial structure of chocolate is significantly enhanced by forming cocoa butter as an oil-in-water emulsion and grinding it under cooling to form solid particles, which are then added to the chocolate matrix in an amount of 2% to 10% by weight, but at higher temperatures during the chocolate making process, the particles tend to melt and release water droplets, which ultimately leads to a chocolate with too high a viscosity to be suitable for de-moulding.

EP 0393327 discloses a method for preparing heat-resistant chocolate by adding a water-in-oil emulsion to form a three-dimensional network structure of sugar crystals and increase oil-binding sites, which can keep the chocolate structure stable when the oil is melted, but this method requires a period of time of more than 20 days and is not suitable for popularization and application.

It has been reported that chocolate bloom can be relieved by selecting cocoa butter substitutes with higher melting points, but many cocoa butter substitutes cause chocolate to have waxy mouthfeel, have low crowd acceptance and cannot be widely applied.

Disclosure of Invention

One of the objects of the present invention is to provide a polyglycerol ricinoleate-porous starch complex.

The second object of the present invention is to provide a method for preparing the polyglycerol polyricinoleate-porous starch composite.

The invention also aims to provide anti-frost chocolate added with the polyglycerol polyricinoleate-porous starch compound.

The fourth purpose of the invention is to provide a preparation method of the anti-frost chocolate.

The technical scheme adopted by the invention is as follows:

the polyglycerol ricinoleate-porous starch composite comprises porous starch, polyglycerol ricinoleate loaded in porous starch pore channels and cocoa butter loaded in porous starch pore channels.

The preparation method of the polyglycerol ricinoleate-porous starch compound comprises the following steps: firstly, mixing polyglycerol ricinoleate and cocoa butter to prepare a mixed solution, adding porous starch into the mixed solution for loading, and finally removing the mixed solution which does not participate in loading to obtain the polyglycerol ricinoleate-porous starch compound.

Preferably, the preparation method of the polyglycerol polyricinoleate-porous starch compound comprises the following steps:

1) mixing polyglycerol ricinoleate and cocoa butter to obtain a mixed solution;

2) preparing starch into starch slurry by using acetic acid-sodium acetate buffer solution, adding alpha-amylase and glucose glucoamylase for enzymolysis, and then performing suction filtration, washing, drying and sieving to obtain porous starch;

3) adding porous starch into the mixed solution obtained in the step 1), performing ultrasonic treatment, performing suction filtration, drying the filtered solid to constant weight, crushing, and sieving to obtain the polyglycerol ricinoleate-porous starch compound.

Further preferably, the preparation method of the polyglycerol polyricinoleate-porous starch composite comprises the following steps:

1) mixing polyglycerol ricinoleate and cocoa butter to obtain a mixed solution;

2) preparing starch into starch slurry by using acetic acid-sodium acetate buffer solution, adding alpha-amylase and glucose glucoamylase, then placing the starch slurry in a water bath for enzymolysis at constant temperature, adjusting the pH of the enzymolysis solution to 2.5-3.5, keeping the pH for 10-15 min to stop the reaction, adjusting the pH of the enzymolysis solution to 6.5-8.0, and then performing suction filtration, water washing, drying and sieving to obtain porous starch;

3) adding porous starch into the mixed solution obtained in the step 1), performing ultrasonic treatment, performing vacuum filtration, performing forced air drying on the filtered solid to constant weight, crushing, and sieving to obtain the polyglycerol ricinoleate-porous starch compound.

Preferably, the mass ratio of the polyglycerol ricinoleate to the cocoa butter in the step 1) is 1-3: 80-90.

Preferably, the starch of step 2) is corn starch.

Preferably, the pH value of the acetic acid-sodium acetate buffer solution in the step 2) is 4.3-7.

Preferably, the mass concentration of the starch slurry in the step 2) is 20-30%.

Preferably, the volume ratio of the alpha-amylase to the glucose saccharifying enzyme in the step 2) is 1: 1-3: 1.

Preferably, the alpha-amylase of step 2)Is added in an amount of 2X 10^-2mL/g dry base starch 3X 10^-2mL/g dry base starch.

Preferably, the glucose-saccharifying enzyme in step 2) is added in an amount of 2X 10^-2mL/g dry base starch 3X 10^-2mL/g dry base starch.

Preferably, the enzymolysis in the step 2) is carried out at 55-60 ℃, and the enzymolysis time is 24-36 h.

Preferably, the mass ratio of the porous starch and the mixed solution in the step 3) is 6-8: 1-2.

Preferably, the ultrasonic treatment in the step 3) is carried out at the temperature of 40-45 ℃ and the ultrasonic power of 300-400W, and the ultrasonic treatment time is 20-30 min. The polyglycerol ricinoleate can be uniformly distributed in the internal structure of the porous starch by combining ultrasonic treatment and vacuum filtration, so that the hydrophobicity of the porous structure is improved, the interaction between the porous starch and the grease in the chocolate matrix is increased, the migration rate of the grease is reduced, and the frost change of the chocolate can be inhibited.

Preferably, the forced air drying in the step 3) is carried out at the temperature of 20-25 ℃, and the drying time is 5-10 h.

Preferably, the sieving in step 3) is 200 mesh sieving.

An anti-frosting chocolate is added with the polyglycerol ricinoleate-porous starch compound.

Preferably, the frost-resistant chocolate comprises the following components in parts by mass:

cocoa butter: 30-36 parts of a solvent;

cocoa powder: 9-12 parts;

milk powder: 23-26 parts;

sucrose: 30-33 parts;

the polyglycerol ricinoleate-porous starch compound comprises the following components: 0.9 to 9 portions.

The preparation method of the frost-resistant chocolate comprises the following steps:

1) melting cocoa butter to obtain liquid cocoa butter;

2) crushing and sieving sucrose to obtain sucrose powder;

3) adding cocoa powder, milk powder and sucrose powder into liquid cocoa butter, heating, mixing, and fine grinding to obtain chocolate slurry;

4) and adding the polyglycerol polyricinoleate-porous starch compound into the chocolate paste, mixing, casting and molding, cooling and demolding to obtain the frost-resistant chocolate.

Preferably, the melting in step 1) is carried out at a temperature of 40 ℃ to 45 ℃.

Preferably, the sieving in step 2) is 200 mesh sieving.

Preferably, the heating and mixing in the step 3) are carried out at the temperature of 40-45 ℃, and the heating and mixing time is 2-3 h.

Preferably, the fine grinding in the step 3) is carried out at the temperature of 40-45 ℃, and the fine grinding time is 15-20 h.

Preferably, the average particle size of the solid matters in the chocolate mass in the step 3) is 20 to 25 μm.

The invention has the beneficial effects that: the frost-resistant chocolate has excellent frost resistance, solves the problem of quality reduction of chocolate in the processes of high-temperature transportation and storage, and improves the shelf life of products.

Specifically, the method comprises the following steps:

1) the polyglycerol ricinoleate-porous starch compound is added into the anti-frost chocolate, the specific surface area of the porous starch is large, the porous starch has binding and fixing effects on cocoa butter, the stability of a chocolate space network structure is facilitated, the particle size of the porous starch is about 15 mu m and is lower than the particle size of a dispersed phase in the traditional chocolate, and the high-density bulk component can be filled in narrow gaps of a chocolate matrix, so that the migration rate of the cocoa butter can be reduced, and the frost change of the chocolate is reduced;

2) the polyglycerol ricinoleate-porous starch compound is added into the frost-resistant chocolate, and the polyglycerol ricinoleate is uniformly distributed in the porous structure of the porous starch, so that the adsorption effect of cocoa butter and the porous structure can be enhanced, and the formation of fat frost is reduced;

3) the anti-frost chocolate is simple in preparation method, wide in raw material source, low in cost and wide in market application prospect.

Drawings

FIG. 1 is a graph of whiteness index versus time for the chocolates of examples 1-3 and comparative examples 1-4.

Detailed Description

The invention will be further explained and illustrated with reference to specific examples.

Example 1:

a polyglycerol ricinoleate-porous starch compound is prepared by the following steps:

1) mixing polyglycerol ricinoleate and cocoa butter according to the mass ratio of 1:40, and uniformly stirring to obtain a mixed solution;

2) mixing corn starch with acetic acid-sodium acetate buffer solution to obtain starch slurry with mass fraction of 25% (corn starch dry basis mass fraction) and pH of 6, and adding at an amount of 3 × 10^-2Adding hydrolase into mL/g dry starch, wherein the volume ratio of alpha-amylase to glucose glucoamylase in the hydrolase is 3:1, then placing starch slurry in a water bath for enzymolysis at a constant temperature of 58 ℃ for 36h, then adjusting the pH of the enzymolysis solution to 3 by using an HCl solution, keeping the pH for 10min to stop the reaction, then adjusting the pH of the enzymolysis solution to 7 by using an NaOH solution, carrying out vacuum filtration, washing the filtered solid by using distilled water, then placing the solid in a forced air drying oven for drying at 40 ℃ for 36h, crushing, and sieving by using a 100-mesh sieve to obtain porous starch;

3) adding porous starch into the mixed liquor obtained in the step 1), wherein the mass ratio of the porous starch to the mixed liquor is 6:1, carrying out ultrasonic treatment for 25min at the temperature of 42 ℃ and the ultrasonic power of 350W, carrying out vacuum filtration for 35min, carrying out forced air drying on the filtered solid at the temperature of 22 ℃ for 10h until the weight is constant, crushing, and sieving with a 200-mesh sieve to obtain the polyglycerol ricinoleate-porous starch compound.

The anti-frost chocolate comprises the following components in parts by mass: 33 parts of cocoa butter, 9 parts of cocoa powder, 25 parts of milk powder, 33 parts of cane sugar and 8.7 parts of polyglycerol polyricinoleate-porous starch compound, wherein the preparation method comprises the following steps:

1) melting cocoa butter in water bath at 43 deg.C to obtain liquid cocoa butter;

2) crushing sucrose, and sieving with a 200-mesh sieve to obtain sucrose powder;

3) adding cocoa powder, milk powder and sucrose powder into liquid cocoa butter, adding soybean lecithin accounting for 0.2 percent of the total mass of the cocoa powder, the milk powder, the sucrose powder and the liquid cocoa butter, mixing for 3 hours at 43 ℃, transferring the material into a refiner, and finely grinding for 20 hours at 43 ℃ until the average particle size of solid matters in the mixed pulp is 20-25 mu m to obtain chocolate pulp;

4) and adding the polyglycerol polyricinoleate-porous starch compound into the chocolate slurry, uniformly mixing, casting and molding, cooling and demolding to obtain the frost-resistant chocolate.

Example 2:

a polyglycerol ricinoleate-porous starch compound is prepared by the following steps:

1) mixing polyglycerol ricinoleate and cocoa butter according to the mass ratio of 1:30, and uniformly stirring to obtain a mixed solution;

2) mixing corn starch with acetic acid-sodium acetate buffer solution to obtain starch slurry with mass fraction of 20% (corn starch dry basis mass fraction) and pH of 7, and adding 2 × 10^-2Adding hydrolase into mL/g dry starch, wherein the volume ratio of alpha-amylase to glucose glucoamylase in the hydrolase is 2:1, placing starch slurry in a water bath for enzymolysis at a constant temperature of 60 ℃ for 30h, adjusting the pH of the enzymolysis solution to 3.5 by using an HCl solution, keeping for 15min to terminate the reaction, adjusting the pH of the enzymolysis solution to 8 by using an NaOH solution, performing vacuum filtration, washing the filtered solid by using distilled water, drying in a forced air drying oven at 43 ℃ for 24h, crushing, and sieving by using a 100-mesh sieve to obtain porous starch;

3) adding porous starch into the mixed liquid obtained in the step 1), wherein the mass ratio of the porous starch to the mixed liquid is 7:2, carrying out ultrasonic treatment for 20min at the temperature of 45 ℃ and the ultrasonic power of 400W, carrying out vacuum filtration for 40min, placing the filtered solid at the temperature of 25 ℃ for forced air drying for 8h to constant weight, crushing, and sieving with a 200-mesh sieve to obtain the polyglycerol ricinoleate-porous starch compound.

The anti-frost chocolate comprises the following components in parts by mass: 36 parts of cocoa butter, 11 parts of cocoa powder, 23 parts of milk powder, 30 parts of cane sugar and 4.2 parts of polyglycerol polyricinoleate-porous starch compound, wherein the preparation method comprises the following steps:

1) melting cocoa butter in water bath at 40 deg.C to obtain liquid cocoa butter;

2) crushing sucrose, and sieving with a 200-mesh sieve to obtain sucrose powder;

3) adding cocoa powder, milk powder and sucrose powder into liquid cocoa butter, adding soybean lecithin accounting for 0.2 percent of the total mass of the cocoa powder, the milk powder, the sucrose powder and the liquid cocoa butter, mixing for 2 hours at 45 ℃, transferring the material into a refiner, and finely grinding for 15 hours at 45 ℃ until the average particle size of solid matters in the mixed pulp is 20-25 mu m to obtain chocolate pulp;

4) and adding the polyglycerol polyricinoleate-porous starch compound into the chocolate slurry, uniformly mixing, casting and molding, cooling and demolding to obtain the frost-resistant chocolate.

Example 3:

a polyglycerol ricinoleate-porous starch compound is prepared by the following steps:

1) mixing polyglycerol ricinoleate and cocoa butter according to the mass ratio of 1:85, and uniformly stirring to obtain a mixed solution;

2) mixing corn starch with acetic acid-sodium acetate buffer solution to obtain starch slurry with mass fraction of 30% (corn starch dry basis mass fraction) and pH of 4.3, and adding 2.5 × 10^-2Adding hydrolase into mL/g dry starch, wherein the volume ratio of alpha-amylase to glucose glucoamylase in the hydrolase is 2.5:1, placing starch slurry in a water bath for enzymolysis at the constant temperature of 55 ℃ for 24 hours, adjusting the pH of an enzymolysis solution to 2.5 by using an HCl solution, keeping for 13 minutes to terminate the reaction, adjusting the pH of the enzymolysis solution to 6.5 by using an NaOH solution, carrying out vacuum filtration, washing the filtered solid by using distilled water, drying in a forced air drying oven at 45 ℃ for 30 hours, crushing, and sieving by using a 100-mesh sieve to obtain porous starch;

3) adding porous starch into the mixed liquor obtained in the step 1), wherein the mass ratio of the porous starch to the mixed liquor is 8:1.5, carrying out ultrasonic treatment for 30min at the temperature of 40 ℃ and the ultrasonic power of 300W, carrying out vacuum filtration for 30min, carrying out forced air drying on the filtered solid at the temperature of 20 ℃ for 10h to constant weight, crushing, and sieving with a 200-mesh sieve to obtain the polyglycerol ricinoleate-porous starch compound.

The anti-frost chocolate comprises the following components in parts by mass: 30 parts of cocoa butter, 12 parts of cocoa powder, 26 parts of milk powder, 32 parts of cane sugar and 1 part of polyglycerol polyricinoleate-porous starch compound, wherein the preparation method comprises the following steps:

1) melting cocoa butter in water bath at 45 deg.C to obtain liquid cocoa butter;

2) crushing sucrose, and sieving with a 200-mesh sieve to obtain sucrose powder;

3) adding cocoa powder, milk powder and sucrose powder into liquid cocoa butter, adding soybean lecithin accounting for 0.2 percent of the total mass of the cocoa powder, the milk powder, the sucrose powder and the liquid cocoa butter, mixing for 2.5 hours at 40 ℃, transferring the material into a refiner, and finely grinding for 18 hours at 40 ℃ until the average particle size of solid matters in the mixed slurry is 20-25 mu m to obtain chocolate slurry;

4) and adding the polyglycerol polyricinoleate-porous starch compound into the chocolate slurry, uniformly mixing, casting and molding, cooling and demolding to obtain the frost-resistant chocolate.

Comparative example 1:

the chocolate comprises the following components in parts by mass: 33 parts of cocoa butter, 9 parts of cocoa powder, 25 parts of milk powder and 33 parts of cane sugar, and the preparation method comprises the following steps:

1) melting cocoa butter in water bath at 43 deg.C to obtain liquid cocoa butter;

2) crushing sucrose, and sieving with a 200-mesh sieve to obtain sucrose powder;

3) adding cocoa powder, milk powder and sucrose powder into liquid cocoa butter, adding soybean lecithin accounting for 0.2 percent of the total mass of the cocoa powder, the milk powder, the sucrose powder and the liquid cocoa butter, mixing for 3 hours at 43 ℃, transferring the material into a refiner, and finely grinding for 20 hours at 43 ℃ until the average particle size of solid matters in the mixed pulp is 20-25 mu m to obtain chocolate pulp;

4) and (4) casting and molding the chocolate slurry, and cooling and demolding to obtain the chocolate.

Comparative example 2:

the chocolate comprises the following components in parts by mass: 33 parts of cocoa butter, 9 parts of cocoa powder, 25 parts of milk powder and 33 parts of cane sugar, and the preparation method comprises the following steps:

1) melting cocoa butter in water bath at 43 deg.C to obtain liquid cocoa butter;

2) crushing sucrose, and sieving with a 200-mesh sieve to obtain sucrose powder;

3) adding cocoa powder, milk powder and sucrose powder into liquid cocoa butter, adding soybean lecithin accounting for 0.2 percent of the total mass of the cocoa powder, the milk powder, the sucrose powder and the liquid cocoa butter, mixing for 3 hours at 43 ℃, transferring the material into a refiner, and finely grinding for 20 hours at 43 ℃ until the average particle size of solid matters in the mixed pulp is 20-25 mu m to obtain chocolate pulp;

4) adding polyglycerol polyricinoleate accounting for 0.03 percent of the total mass of the chocolate paste into the chocolate paste, uniformly mixing, then casting and molding, cooling and demolding to obtain the chocolate.

Comparative example 3:

the chocolate comprises the following components in parts by mass: 33 parts of cocoa butter, 9 parts of cocoa powder, 25 parts of milk powder and 33 parts of cane sugar, and the preparation method comprises the following steps:

1) melting cocoa butter in water bath at 43 deg.C to obtain liquid cocoa butter;

2) crushing sucrose, and sieving with a 200-mesh sieve to obtain sucrose powder;

3) adding cocoa powder, milk powder and sucrose powder into liquid cocoa butter, adding soybean lecithin accounting for 0.2 percent of the total mass of the cocoa powder, the milk powder, the sucrose powder and the liquid cocoa butter, mixing for 3 hours at 43 ℃, transferring the material into a refiner, and finely grinding for 20 hours at 43 ℃ until the average particle size of solid matters in the mixed pulp is 20-25 mu m to obtain chocolate pulp;

4) and adding the porous starch accounting for 8.64 percent of the total mass of the chocolate paste into the chocolate paste, uniformly mixing, then casting and molding, cooling and demolding to obtain the chocolate.

Comparative example 4:

the chocolate comprises the following components in parts by mass: 33 parts of cocoa butter, 9 parts of cocoa powder, 25 parts of milk powder and 33 parts of cane sugar, and the preparation method comprises the following steps:

1) melting cocoa butter in water bath at 43 deg.C to obtain liquid cocoa butter;

2) crushing sucrose, and sieving with a 200-mesh sieve to obtain sucrose powder;

3) adding cocoa powder, milk powder and sucrose powder into liquid cocoa butter, adding soybean lecithin accounting for 0.2 percent of the total mass of the cocoa powder, the milk powder, the sucrose powder and the liquid cocoa butter, mixing for 3 hours at 43 ℃, transferring the material into a refiner, and finely grinding for 20 hours at 43 ℃ until the average particle size of solid matters in the mixed pulp is 20-25 mu m to obtain chocolate pulp;

4) adding polyglycerol polyricinoleate accounting for 0.03 percent of the total mass of the chocolate paste and porous starch accounting for 8.64 percent of the total mass of the chocolate paste into the chocolate paste, uniformly mixing, then casting and molding, cooling and demolding to obtain the chocolate.

And (3) performance testing:

the chocolates obtained in examples 1 to 3 and comparative examples 1 to 4 were placed in trays, respectively, the trays were placed in a low-temperature oven with a relative humidity of 80%, the temperature was continuously maintained at 30 ℃ for 8 hours, then at 18 ℃ for 16 hours, as a temperature cycle, an accelerated blooming test was performed for 8 weeks, the change in color of the chocolate surface was measured every 1 week with a colorimeter, and the lightness L was recorded: from black to white (0 to 100); a: green to red (-120 to 120); b: blue to yellow (-120 to 120), and the Whiteness Index (WI) was calculated according to the following formula:the graph of whiteness index versus time is plotted as shown in figure 1.

As can be seen from fig. 1: the frost resistance of the chocolate is greatly improved after the polyglycerol ricinoleate-porous starch compound is added into the chocolate, and although the chocolate with the polyglycerol ricinoleate or the porous starch compound or the polyglycerol ricinoleate and the porous starch directly added into the chocolate has a certain frost resistance effect, the improvement of the frost resistance of the chocolate is not obvious.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.