Method for preparing chocolate with high heat resistance, blooming resistance, high dietary fiber and low saturated fatty acid based on biphasic gel and product

Abstract

The invention discloses a method for preparing chocolate with high heat resistance, blooming resistance, high dietary fiber and low saturated fatty acid based on biphase gel and a product, and belongs to the technical field of oil processing application, and the method comprises the following steps: adding an emulsifier and solid fat into edible vegetable oil, and heating and stirring until the emulsifier and the solid fat are completely molten to obtain an oil gel phase; adding dietary fibers into water, and completely dissolving the dietary fibers to form a hydrogel phase; and mixing the obtained hydrogel phase and the oil gel phase, carrying out high-speed shearing emulsification, and cooling to room temperature in an ice-water bath to obtain the biphase gel. Different types of biphase gels are prepared by adjusting the ratio of the oil phase to the water phase, and the biphase gels are used for partially replacing cocoa butter to prepare the chocolate, so that the fat content is reduced, the heat resistance of the chocolate is improved, the frosting phenomenon of the chocolate is effectively delayed, the prepared chocolate does not contain trans-fatty acids, the saturated fatty acids are reduced, and the chocolate has good stability. And dietary fibers are contained, so that human health is benefited.

Description

Technical Field

[0001] The present invention belongs to the technical field of oil processing and application, and in particular relates to a method and product for preparing chocolate with high heat resistance, blooming resistance, high dietary fiber and low saturated fatty acid based on a two-phase gel. Background Art

[0002] Chocolate's unique taste, texture, and flavor are highly dependent on its primary fat component, cocoa butter. However, the inherent physical and chemical properties of cocoa butter pose significant challenges to chocolate products, particularly in terms of heat resistance, bloom resistance, and health attributes:

[0003] Insufficient heat resistance: Cocoa butter completely melts at temperatures of 35-37°C, causing chocolate to easily soften, deform, or even melt in tropical environments or slightly higher temperatures. This seriously hinders its sales in warm regions and significantly increases the cost and difficulty of logistics, transportation, and storage.

[0004] Poor bloom resistance: Fat bloom is a major quality issue that has long plagued the chocolate industry. This is manifested as an off-white frost on the surface of chocolate during storage. This not only seriously affects the product's appearance and consumer acceptance, but also impairs its texture and taste.

[0005] Health risks (high saturated fatty acids): Traditional chocolate typically contains 30%-40% cocoa butter, of which saturated fatty acids account for nearly 60%. Excessive intake of saturated fatty acids increases the risk of chronic diseases such as cardiovascular disease, diabetes, and obesity. The World Health Organization (WHO) recommends that saturated fatty acid intake should be less than 10% of total daily energy, raising serious health concerns about traditional chocolate.

[0006] Low dietary fiber: Traditional chocolate recipes usually lack dietary fiber, which is an important nutrient widely advocated in modern healthy diets. It has many benefits such as regulating intestinal function and controlling blood sugar and blood lipids.

[0007] In order to meet the above challenges, especially to improve heat resistance, bloom resistance and reduce saturated fatty acid content, researchers have explored a variety of fat replacement strategies. Traditional solutions mainly include cocoa butter equivalents (CBE), lauric acid cocoa butter substitutes (CBS) and non-lauric acid cocoa butter substitutes (CBR). Among them, cocoa butter equivalents are favored because their triglyceride composition is similar to that of natural cocoa butter and they can better maintain the physical properties of chocolate. However, simply reducing the total fat content or replacing part of the cocoa butter is often difficult to significantly reduce the saturated fatty acid content and introduce healthy dietary fiber while maintaining the ideal texture, taste and flavor of chocolate.

[0008] In recent years, new structural lipids such as oleogels, hydrogels, emulsion gels and biphasic gels have shown potential as healthy fat substitutes. Biphasic gels combine the properties of oleogels and hydrogels to form a structurally stable dual-network system. This unique structural characteristic gives it the multiple advantages of theoretically accommodating water-soluble healthy ingredients (such as dietary fiber) and significantly reducing the amount of highly saturated oils (such as cocoa butter). Although biphasic gels have been widely studied in the pharmaceutical and cosmetic fields, their application in the food industry is still in the initial exploratory stage. Preliminary studies have shown that biphasic gels can effectively improve the texture and stability of meat products, biscuits and spreadable butters.

[0009] However, to date, there has been no research on using biphasic gel as a fat substitute or functional carrier to systematically and simultaneously achieve the four major goals of "high heat resistance", "excellent anti-blooming properties", "significantly increased dietary fiber content" and "effectively reduced saturated fatty acid content" in the chocolate system. Summary of the Invention

[0010] The purpose of this section is to summarize some aspects of embodiments of the present invention and to briefly introduce some preferred embodiments.

[0011] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0012] Therefore, the purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing chocolate with high heat resistance, blooming resistance, high dietary fiber and low saturated fatty acid based on a two-phase gel.

[0013] In order to solve the above technical problems, the present invention provides the following technical solution: a method for preparing chocolate with high heat resistance, anti-blooming, high dietary fiber and low saturated fatty acid based on a two-phase gel, comprising:

[0014] Preparation of biphasic gel: Add emulsifier and solid fat to edible vegetable oil, heat and stir until completely melted to obtain oil gel phase;

[0015] Add dietary fiber into water and make it completely dissolved to form a hydrogel phase;

[0016] The obtained hydrogel phase and oil gel phase are mixed, emulsified at high shear speed, and then cooled to room temperature in an ice-water bath to obtain a two-phase gel;

[0017] Preparation of chocolate: Heat cocoa butter until melted, add cocoa powder, powdered sugar, and soy lecithin, mix well, and ball mill. Add biphasic gel and continue ball milling to obtain a mixed liquid.

[0018] The mixed liquid is subjected to temperature adjustment, cooled and demoulded to obtain chocolate.

[0019] As a preferred embodiment of the method of the present invention, the emulsifier is one or more of monoglyceride, mono- and diglyceride, and polyglycerol ricinoleate;

[0020] The amount of the emulsifier added is 1 to 10 wt % of the oil phase.

[0021] As a preferred embodiment of the method of the present invention, the solid fat is one or more of cocoa butter equivalent, lauric acid cocoa butter substitute and non-lauric acid cocoa butter substitute;

[0022] The edible vegetable oil is one or more of soybean oil, peanut oil, corn oil, coconut oil, sunflower oil, rapeseed oil, rice bran oil, olive oil, cottonseed oil, almond oil, tea seed oil, and sesame oil;

[0023] The ratio of the edible vegetable oil to the solid fat is (1-3):1.

[0024] As a preferred embodiment of the method of the present invention, the heating and stirring process has a heating temperature of 75 to 90° C. and a stirring time of 30 to 60 minutes.

[0025] As a preferred embodiment of the method of the present invention, the dietary fiber is one or more of citrus fiber, polydextrose, inulin and isomaltooligosaccharide;

[0026] The dietary fiber is added in an amount of 1 to 4 wt% of the hydrogel phase;

[0027] The cooling process is carried out with ice water at a temperature of 2±2° C. and a cooling time of 10 to 30 minutes.

[0028] As a preferred embodiment of the method of the present invention, wherein: the hydrogel phase and the oleogel phase are mixed, wherein the amount of the oleogel phase added is 20 to 50 wt %, to obtain an O / W type two-phase gel;

[0029] The amount of oil phase added is 60-80 wt% to obtain a W / O type two-phase gel;

[0030] The addition amount of the oil phase was 55 wt %, and a bicontinuous two-phase gel was obtained;

[0031] The shear emulsification has a rotation speed of 5000 to 10000 rpm and a time of 1 to 4 minutes.

[0032] As a preferred embodiment of the method of the present invention, the cocoa butter accounts for 20-40%, the cocoa powder accounts for 25-35%, the powdered sugar accounts for 25-35%, the two-phase gel accounts for 10-30%, and the soy lecithin accounts for 0.1-1%, calculated by weight percentage of the raw materials.

[0033] As a preferred embodiment of the method of the present invention, the ball milling is carried out in a planetary ball mill for 6 to 8 hours.

[0034] As a preferred embodiment of the method of the present invention, the temperature adjustment treatment is to first heat the feed liquid to 45-50°C, then cool it to 27-28°C, and then heat it to 31-32°C.

[0035] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a chocolate product with high heat resistance, bloom resistance, high dietary fiber and low saturated fatty acid.

[0036] Beneficial effects of the present invention:

[0037] The present invention produces different types of two-phase gels by adjusting the ratio of oil and water phases, and uses the two-phase gel to partially replace cocoa butter to produce chocolate. This reduces the fat content while improving the heat resistance of the chocolate and effectively delaying the blooming of the chocolate. The produced chocolate does not contain trans fatty acids and contains dietary fiber, which is beneficial to human health. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort. Among them:

[0039] Figure 1 The hardness diagram of the chocolate prepared in Examples 1 to 6 and Comparative Examples 1 to 2.

[0040] Figure 2 The shape retention index and actual pictures of the chocolates prepared in Examples 1 to 6 and Comparative Examples 1 to 2 are shown.

[0041] Figure 3 Figures 1 and 2 show the whiteness index changes and the actual images of the chocolates prepared in Examples 1-6 and Comparative Examples 1-2 under constant and cyclic temperature conditions. Figures A and B show the WI change graphs of the chocolate samples under constant and cyclic temperature storage conditions, respectively. Figures C and D show the actual images of the chocolate samples under constant and cyclic temperature storage conditions, respectively.

[0042] Figure 4 The figures show the crystal forms of the chocolates prepared in Examples 1-6 and Comparative Examples 1-2 under constant temperature and cycled temperature storage. A and B are X-ray diffraction patterns of fresh chocolate, C and D are X-ray diffraction patterns of chocolate stored for 21 days, and E and F are X-ray diffraction patterns of chocolate stored for 45 days.

[0043] Figure 5These are crystal morphologies of the chocolates prepared in Examples 1 to 6 and Comparative Examples 1 to 2, wherein A is a polarized light image of the surface of fresh chocolate, and B is a polarized light image of the surface of frosted chocolate.

[0044] Figure 6 The diagram shows the sensory evaluation results of the chocolates prepared in Examples 1 to 6 and Comparative Examples 1 to 2.

[0045] Figure 7 This is a graph showing the results of a temperature-dependent blooming test on the chocolate prepared in Comparative Example 4. DETAILED DESCRIPTION

[0046] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0047] Unless otherwise specified, the raw materials used in the examples were purchased commercially.

[0048] The performance testing method used in the following examples is:

[0049] Shape Retention Index (SRI): (1) Weigh the chocolate bar after storing it at 20°C for 1 day and measure its width. (2) Place the chocolate bar on a tray and place it in a 40°C oven for 1 hour. (3) After 1 hour, allow the tray to fall freely from a height of 18 inches (about 45 cm) and land flat on a test platform. (4) Cool the chocolate bar at 20°C for 2 hours and remeasure its width along the length of the sample. The SRI value of chocolate is calculated using the following formula:

[0050]

[0051] Where d1 and d2 are the average widths (cm) of the chocolate before and after stabilization at 40°C, and w is the mass of the chocolate (g). Each value was measured in triplicate. s is the test sample, and c is the control sample (in this formula, the control is the chocolate from Control Group I). If there is no significant difference between the test and blank groups, the SRI is 0; if the sample maintains its shape, the SRI is 100. A higher SRI value indicates less deformation and better thermal stability. Take photos of the chocolate at both measurements.

[0052] Hardness: The chocolate was stabilized at 32°C for 8 hours. The hardness of the chocolate during storage was measured using a TA.XT Plus physical property analyzer. The instrument measurement conditions were: P / 2 probe, probe height 15 mm from the sample, probe descent test speed 1.0 mm / s, puncture test speed 1.0 mm / s, probe return speed 1.0 mm / s, and a pressure depth of 6 mm. The sample was measured three times.

[0053] Whiteness Index (WI): Chocolate's bloom stability during storage was measured using an UltraScan Pro1166 spectrophotometer, using both constant-temperature and variable-temperature bloom tests. The constant-temperature bloom test was set at 20°C; the variable-temperature bloom test was set at 20°C for the first 17 hours of each day and 29°C for the last 7 hours. To prevent humidity fluctuations caused by the presence of moisture in the air, all chocolate was sealed in airtight bags and stored for 45 days. Measurements were taken on the first, seventh, fifteenth, 30th, and 45th days of storage.

[0054] Before measuring the samples, the instrument was set to reflection mode and calibrated using a blackboard and then a whiteboard. The chocolate samples were then placed in a transparent ziplock bag and placed at the test site. Taking into account the uneven surface of the bloomed chocolate samples, three different locations were randomly selected for measurement for each group of samples. The instrument automatically read the L* (brightness / whiteness), a* (redness / greenness), and b* (yellowness / blueness) values ​​of the samples, and calculated the whiteness index (WI) according to the following formula to characterize the degree of blooming of the chocolate during storage. The larger the value, the more severe the blooming.

[0055] Crystalline form determination: X-ray diffraction patterns were used to determine the crystallographic evolution of the chocolate on days 1, 21, and 45 of constant and variable temperature storage. Instrument parameters: Cu-Kα source (λ = 1.54058, 40 kV, 30 mA), 2θ scanning from 10.0° to 30.0°, with a measurement step size of 0.02°. To eliminate the interference of sugar crystals in the chocolate with cocoa butter crystals, the chocolate blocks were chopped with a knife, mixed with 500 mL of deionized water, and allowed to stand at room temperature for 24 hours. The sugar-free chocolate powder was then recovered by vacuum filtration and pressed with clean paper to remove any residual surface moisture. The chocolate was then spread flat and air-dried for later use.

[0056] Crystal morphology: The surface morphology of the chocolate was observed using a polarizing microscope (XPH-25C, PuDa Co., Ltd., China) equipped with a digital camera. The surface components of the chocolate were carefully scraped and placed on a glass slide. To eliminate interference from sugar, deionized water was injected between the slide and the coverslip. The surface morphology of the fresh chocolate and the chocolate after 45 days of temperature cycling was observed at a magnification of 200x (10 × 20).

[0057] Sensory Evaluation: Twenty trained panelists familiar with chocolate properties and descriptive analytical methods were selected. Using the evaluation criteria in Table 1, panelists were asked to observe and taste the samples, then evaluate the chocolate's appearance, firmness, sweetness, flavor, palatability, and overall acceptance. Each sensory attribute was evaluated on a continuous linear scale ranging from 1 (not noticeable) to 9 (high intensity).

[0058] Table 1

[0059]

[0060] Example 1

[0061] A low-fat chocolate with improved heat resistance and bloom resistance and a preparation method thereof, comprising the following steps:

[0062] (1) Preparation of O / W biphasic gel:

[0063] Oil phase preparation: 4% (w / w) monoglyceride was mixed with 96% (w / w) mixed oil (cocoa butter equivalent: soybean oil = 1:1, mass ratio) and heated to 85°C to completely melt the monoglyceride to form a uniform oil gel solution;

[0064] Preparation of aqueous phase: 2% (w / w) citrus fiber was slowly added to deionized water and magnetically stirred at room temperature to form a homogeneous hydrogel solution;

[0065] The prepared oleogel and hydrogel were mixed at a ratio of 4:6 (mass ratio) at 85 °C and then homogenized and emulsified using a high-speed disperser at 8000 r / min for 2 min;

[0066] The obtained emulsion gel was then stirred and cooled in an ice-water bath at 2° C. for 10 min to obtain an O / W two-phase gel.

[0067] (2) Chocolate formula: 30% cocoa butter, 10% dual-phase gel, 30% cocoa powder, 29.5% powdered sugar, and 0.5% soy lecithin, based on the percentage by mass of the raw materials;

[0068] (3) Mixing: Place cocoa butter, cocoa powder, powdered sugar, and soy lecithin in a container and heat in a water bath at 60°C, stirring continuously until completely melted;

[0069] (4) Fine grinding: The mixed ingredients were first finely ground in a laboratory planetary ball mill; then, the dual-phase gel was added to the mixture and fine grinding was continued until the fineness of the chocolate slurry was less than 20 μm as measured by a fineness meter;

[0070] (5) Temperature adjustment: The slurry after fine grinding is temperature adjusted, and the temperature adjustment process is to increase the temperature to 45°C, then decrease the temperature to 28°C, and then increase the temperature to 31°C;

[0071] (6) Injection molding: Carefully pour the tempered chocolate paste into the mold and shake it quickly to remove any bubbles.

[0072] (7) Cooling and demoulding: Place the chocolate in a refrigerator at 4°C overnight to allow it to fully solidify before demoulding to obtain Chocolate I.

[0073] Example 2

[0074] A low-fat chocolate with improved heat resistance and bloom resistance and a preparation method thereof, comprising the following steps:

[0075] The chocolate formula in step (2) of Example 1 was adjusted to: 20% cocoa butter, 20% dual-phase gel, and the other ingredients remained the same as in Example 1 to obtain Chocolate II.

[0076] Example 3

[0077] A low-fat chocolate with improved heat resistance and bloom resistance and a preparation method thereof, comprising the following steps:

[0078] (1) Preparation of bicontinuous two-phase gel:

[0079] Oil phase preparation: 4% (w / w) monoglyceride was mixed with 96% (w / w) mixed oil (cocoa butter equivalent: soybean oil = 1:1, mass ratio) and heated to 85°C to completely melt the monoglyceride to form a uniform oil gel solution;

[0080] Preparation of aqueous phase: 2% (w / w) citrus fiber was slowly added to deionized water and magnetically stirred at room temperature to form a homogeneous hydrogel solution;

[0081] The prepared oleogel and hydrogel were mixed at a ratio of 55:45 (mass ratio) at 85 °C and then homogenized and emulsified using a high-speed disperser at 8000 r / min for 2 min;

[0082] The obtained emulsion gel was then stirred and cooled in an ice water bath at 2° C. for 10 min to obtain a bicontinuous two-phase gel.

[0083] (2) Chocolate formula: 30% cocoa butter, 10% dual-phase gel, 30% cocoa powder, 29.5% powdered sugar and 0.5% soy lecithin, calculated by weight of the raw materials.

[0084] (3) Mixing: Heat cocoa butter, cocoa powder, powdered sugar and soy lecithin in a water bath at 60°C, stirring continuously until completely melted.

[0085] (4) Fine grinding: The mixed ingredients were first finely ground in a laboratory planetary ball mill; then, the dual-phase gel was added to the mixture and fine grinding was continued until the fineness of the chocolate slurry was less than 20 μm as measured by a fineness meter.

[0086] (5) Temperature adjustment: The slurry after fine grinding is temperature adjusted, and the temperature adjustment process is to increase the temperature to 45°C, then decrease the temperature to 28°C, and then increase the temperature to 31°C.

[0087] (6) Injection molding: Pour the tempered chocolate paste carefully into the mold and shake it quickly to remove the bubbles.

[0088] (7) Cooling and demoulding: Place the chocolate in a refrigerator at 4°C overnight to allow it to fully solidify before demoulding to obtain Chocolate III.

[0089] Example 4

[0090] A low-fat chocolate with improved heat resistance and bloom resistance and a preparation method thereof, comprising the following steps:

[0091] The chocolate formula in step (2) of Example 3 was adjusted to 20% cocoa butter and 20% dual-phase gel, and the other ingredients were kept the same as in Example 3 to obtain Chocolate IV.

[0092] Example 5

[0093] A low-fat chocolate with improved heat resistance and bloom resistance and a preparation method thereof, comprising the following steps:

[0094] (1) Preparation of W / O type two-phase gel:

[0095] Oil phase preparation: 4% (w / w) GMS was mixed with 96% (w / w) mixed oil (cocoa butter equivalent: soybean oil = 1:1, mass ratio) and heated to 85°C to completely melt the monoglycerides to form a uniform oil gel solution;

[0096] Preparation of aqueous phase: 2% (w / w) citrus fiber was slowly added to deionized water and magnetically stirred at room temperature to form a homogeneous hydrogel solution;

[0097] The prepared oleogel and hydrogel were mixed at a ratio of 7:3 (mass ratio) at 85 °C and then homogenized and emulsified using a high-speed disperser at 8000 r / min for 2 min;

[0098] The obtained emulsion gel was then stirred and cooled in an ice-water bath at 2° C. for 10 min to obtain a W / O type two-phase gel.

[0099] (2) Chocolate formula: 30% cocoa butter, 10% dual-phase gelatin, 30% cocoa powder, 29.5% powdered sugar, and 0.5% soy lecithin, calculated by weight of raw materials;

[0100] (3) Mixing: Heat cocoa butter, cocoa powder, powdered sugar and soy lecithin in a water bath at 60°C, stirring continuously until completely melted;

[0101] (4) Fine grinding: The mixed ingredients were first finely ground in a laboratory planetary ball mill; then, the dual-phase gel was added to the mixture and fine grinding was continued until the fineness of the chocolate slurry was less than 20 μm as measured by a fineness meter.

[0102] (5) Temperature adjustment: The slurry after fine grinding is temperature adjusted, and the temperature adjustment process is to increase the temperature to 45°C, then decrease the temperature to 28°C, and then increase the temperature to 31°C.

[0103] (6) Injection molding: Pour the tempered chocolate paste carefully into the mold and shake it quickly to remove the bubbles.

[0104] (7) Cooling and demoulding: Place the chocolate in a refrigerator at 4°C overnight to allow it to fully solidify before demoulding to obtain chocolate V.

[0105] Example 6

[0106] A low-fat chocolate with improved heat resistance and bloom resistance and a preparation method thereof, comprising the following steps:

[0107] The chocolate formula in step (2) of Example 5 was adjusted to 20% cocoa butter and 20% dual-phase gel, and the other conditions remained the same as in Example 5 to obtain Chocolate VI.

[0108] Example 7

[0109] The preparation method of the chocolate provided in Example 7 is the same as that described in Example 1, except that:

[0110] The monoglyceride in step (1) is replaced by one or more of monoglyceride, mono- and diglyceride, and polyglycerol ricinoleate.

[0111] The obtained chocolate was subjected to performance tests, and the test results were similar to those of Example 1. Compared with the comparative example, the heat resistance and bloom resistance of the chocolate were improved.

[0112] Example 8

[0113] The preparation method of the chocolate provided in Example 8 is the same as that described in Example 3, except that:

[0114] The cocoa butter equivalent in step (1) is replaced by one or more of lauric acid cocoa butter substitute and non-lauric acid cocoa butter substitute.

[0115] The obtained chocolate was subjected to performance tests, and the test results were similar to those of Example 3. Compared with the comparative example, both the heat resistance and bloom resistance of the chocolate were improved.

[0116] Example 9

[0117] The preparation method of the chocolate provided in Example 9 is the same as that described in Example 5, except that:

[0118] The soybean oil in step (1) is replaced by one or more of peanut oil, corn oil, coconut oil, sunflower oil, rapeseed oil, rice bran oil, olive oil, cottonseed oil, almond oil, tea seed oil, and sesame oil.

[0119] The obtained chocolate was subjected to performance tests, and the test results were similar to those of Example 5. Compared with the comparative example, both the heat resistance and bloom resistance of the chocolate were improved.

[0120] Example 10

[0121] The method for preparing the chocolate provided in Example 10 is the same as that described in Example 5, except that:

[0122] The citrus fiber in step (1) is replaced by one or more of polydextrose, inulin and isomaltooligosaccharide.

[0123] The obtained chocolate was subjected to performance tests, and the test results were similar to those of Example 5. Compared with the comparative example, both the heat resistance and bloom resistance of the chocolate were improved.

[0124] Comparative Example 1

[0125] A preparation method of pure cocoa butter chocolate comprises the following steps:

[0126] (1) Chocolate formula: 40% cocoa butter, 30% cocoa powder, 29.5% powdered sugar and 0.5% soy lecithin, calculated by weight of raw materials;

[0127] (2) Mixing: Weigh cocoa butter, cocoa powder, powdered sugar, and soy lecithin in a container, heat in a 60°C water bath, and stir continuously until completely melted;

[0128] (3) Fine grinding: The mixed ingredients were first finely ground in a laboratory planetary ball mill. The fineness of the chocolate paste was measured by a fineness meter and the fine grinding process was stopped when the fineness was less than 20 μm.

[0129] (4) Temperature adjustment: The slurry after fine grinding is temperature adjusted, and the temperature adjustment process is to raise the temperature to 45°C, then cool it to 28°C, and then raise it to 31°C;

[0130] (5) Injection molding: Carefully pour the tempered chocolate paste into the mold and shake it quickly to remove any bubbles.

[0131] (6) Cooling and demoulding: Place the chocolate in a refrigerator at 4°C overnight to allow it to fully solidify before demoulding to obtain chocolate.

[0132] Comparative Example 2

[0133] A preparation method of cocoa butter-like chocolate comprises the following steps:

[0134] (1) Chocolate formula: 40% cocoa butter equivalent, 30% cocoa powder, 29.5% powdered sugar and 0.5% soy lecithin, calculated by weight of raw materials;

[0135] (2) Mixing: Weigh cocoa butter equivalent, cocoa powder, powdered sugar, and soy lecithin into a container, heat in a 60°C water bath, and stir continuously until completely melted;

[0136] (3) Fine grinding: The mixed ingredients were first finely ground in a laboratory planetary ball mill. The fineness of the chocolate paste was measured by a fineness meter and the fine grinding process was stopped when the fineness was less than 20 μm.

[0137] (4) Temperature adjustment: The slurry after fine grinding is temperature adjusted, and the temperature adjustment process is to raise the temperature to 45°C, then cool it to 28°C, and then raise it to 31°C;

[0138] (5) Injection molding: Carefully pour the tempered chocolate paste into the mold and shake it quickly to remove any bubbles.

[0139] (6) Cooling and demoulding: Place the chocolate in a refrigerator at 4°C overnight to allow it to fully solidify before demoulding to obtain chocolate.

[0140] The obtained chocolate was subjected to performance testing, and the test results are as follows:

[0141] Figure 1 The hardness of the chocolate prepared in Examples 1-6 and Comparative Examples 1-2 at 32°C is shown. At 32°C, the partial melting of the cocoa butter and cocoa butter equivalents in Comparative Examples 1 and 2 disrupts their crystal networks, significantly reducing the mechanical strength of the chocolate. Under these conditions, the network structure of the dual-phase gel becomes dominant, and higher substitution rates lead to stronger mechanical support for the dual-phase gel, resulting in increased hardness. In the O / W dual-phase gel, the continuous phase uniformly wets the sucrose particles, and the pectin in the citrus fiber forms hydrogen bonds with the sucrose. This dual effect strengthens the interparticle interactions between the sucrose crystals and reinforces the sugar network. The synergistic effect between the dual-phase gel network and the sugar network results in the highest hardness in Example 2.

[0142] Table 2

[0143]

[0144] Figure 2Table 2 shows the SRI values ​​and images of the chocolates prepared in Examples 1-6 and Comparative Examples 1-2. The chocolates in the examples exhibit higher SRI values, indicating that the addition of the dual-phase gel enhances the chocolate's thermal stability and shape retention. This is attributed to the network structure of the dual-phase gel, which encapsulates melted fat at 40°C, limiting fat migration and thus improving thermal stability. As the proportion of dual-phase gel replacing cocoa butter increases, a stronger gel network forms within the chocolate, leading to higher SRI values ​​and further enhancing heat resistance. Significant differences were observed in the SRI of the chocolates in the examples (P < 0.05). Among them, Chocolate VI exhibited the highest SRI value. As shown in the images, although Chocolate VI softened at 40°C, its shape remained almost unchanged, and its original shape was still clearly visible. This indicates that the W / O dual-phase gel (with oil as the continuous phase) provides stronger structural support at 40°C, making Chocolate VI the most heat-resistant chocolate at high temperatures.

[0145] Figure 3 The WI values ​​of chocolates prepared in Examples 1-6 and Comparative Examples 1-2 at a constant temperature of 20°C (A&C) and a cycle temperature of 20°C / 29°C (B&D) are shown. When stored at 20°C, the WI values ​​of the chocolate samples showed little change (ranging from 23.6 to 26.9), with no noticeable bloom formation. Figure 3 C). This indicates that chocolate can maintain structural stability when stored at 20°C for a short period of time. In contrast, under cycling temperature conditions, the WI value of the control group increased rapidly during storage ( Figure 3 B), frost occurs ( Figure 3 D). This is because high-melting-point triglycerides melt and recrystallize on the chocolate surface during storage, causing blooming. In contrast, the WI values ​​of chocolates based on dual-phase gels increase more slowly, especially chocolate V, which has a significantly lower WI value than the other samples, reflecting its excellent anti-blooming properties. Figure 3 The actual image in D further confirms these results: the control group exhibits significant blooming, while chocolate V exhibits only slight grayish-white spots. Overall, the dual-phase gel, especially the W / O dual-phase gel, significantly improves the blooming resistance of chocolate.

[0146] Figure 4 X-ray diffraction patterns of chocolate prepared in Examples 1-6 and Comparative Examples 1-2 under constant temperature and cycled temperature storage: fresh chocolate (A&B); stored for 21 days (C&D); stored for 45 days (E&F). During constant temperature storage, no significant differences in the diffraction peak positions were observed between all chocolate samples. There are sharp diffraction peaks at d = 3.98, 3.86, 3.75 and There are four medium-intensity peaks at the same time, which confirms the existence of βV crystal form. On the 21st day of temperature cycling, the control group chocolate has multiple crystal forms. The diffraction peaks show obvious changes: The diffraction peak at The medium intensity peak at 3.75 and The peaks at gradually merged, indicating the transformation from βV to βVI crystal form; The diffraction peak at corresponds to the β′ crystal form; the crystal form of the chocolate in Example 1 changed after 45 days, proving that the addition of the dual-phase gel can delay the crystal form transition to a certain extent.

[0147] Figure 5 Polarized light images of the surfaces of fresh (A) and bloomed (B) chocolates prepared in Examples 1-6 and Comparative Examples 1-2. The bloomed chocolate was obtained from a sample stored for 45 days under cyclic temperature conditions. The fresh chocolate sample exhibited uniformly distributed small crystals; after 45 days of cyclic temperature storage, the crystals on the chocolate surface became larger and less uniformly distributed, indicating temperature-induced fat migration and recrystallization. The chocolates in the examples, particularly Example 5, retained their smaller crystals after storage, without large-scale aggregation. This demonstrates that the addition of the dual-phase gel inhibits the growth of fat phase crystals. As a result, the smaller crystals formed a denser network, which restricted the mobility of triglycerides within the chocolate matrix and improved bloom resistance.

[0148] Figure 6 The sensory evaluation results of chocolate samples prepared in Examples 1 to 6 and Comparative Examples 1 to 2 are shown. The sensory evaluation results show that the chocolates prepared in the Examples are sweeter and have lower hardness than those prepared in the Control Group, with Example 5 receiving the closest sensory score to that of the Control Group.

[0149] Comparative Example 3:

[0150] The chocolate formula in step (2) of Example 1 was adjusted to: 10% cocoa butter, 30% dual-phase gel, and the rest remained the same as in Example 1.

[0151] At the initial stage of fine grinding, the viscosity of the chocolate liquid is significantly higher than that of the chocolate prepared with the preferred two-phase gel ratio of the present invention;

[0152] As fine grinding progresses, the viscosity decreases very slowly. The time required to reach the desired particle size is more than 50% longer than other solutions.

[0153] Significantly longer grinding times directly increase energy consumption and equipment usage, significantly increasing the unit production cost of chocolate. Even after a long grinding period to achieve the target particle size, the final chocolate still has a noticeable gritty taste.

[0154] Sensory evaluation showed that the mouthfeel was significantly inferior to that of chocolate prepared using the preferred dual-phase gel ratio of the present invention. This may be because the high ratio of dual-phase gel changes the rheological properties of the material, resulting in an undesirable texture in the final product structure.

[0155] Comparative Example 4:

[0156] The raw material citrus fiber in the aqueous phase preparation of step (1) in Example 1 was replaced with gellan gum, and the other conditions remained the same as in Example 1.

[0157] The experiment found that the viscosity of the hydrogel increased significantly under these experimental conditions, and the time required to reach the desired particle size during fine grinding was more than 50% longer than that of other solutions.

[0158] The significant extension of the grinding time directly leads to increased energy consumption and increased equipment occupancy time, significantly increasing the unit production cost of chocolate.

[0159] Even after a long period of fine grinding to reach the target particle size, agglomeration, high viscosity and a noticeable grittiness in the mouth will occur in the chocolate system.

[0160] like Figure 7 As shown in the figure, obvious blooming occurred one week after the variable temperature blooming test, and grayish-white spots appeared on the surface of the chocolate (the storage temperature was 20°C for the first 17 hours and 29°C for the last 7 hours). This may be because the viscous matrix hindered the orderly arrangement of fat molecules, resulting in defects in the internal crystal structure of the chocolate, accelerated oil migration, and poor frosting stability.

[0161] The two-phase gel prepared by the present invention can form three different types of two-phase gels by changing the ratio of the oil-water two phases.

[0162] The dual-phase gel prepared by the present invention partially replaces cocoa butter, reducing the fat content while also improving the heat resistance and bloom resistance of chocolate. The present invention provides theoretical and practical insights for the development of low-fat, high-stability chocolate.

[0163] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, and all of these should be included in the scope of the present invention.

Claims

1. A method for preparing chocolate with high heat resistance, anti-blooming, high dietary fiber and low saturated fatty acid based on a biphasic gel, characterized by: include, Preparation of biphasic gel: Add emulsifier and solid fat to edible vegetable oil, heat and stir until completely melted to obtain oil gel phase; Add dietary fiber into water and make it completely dissolved to form a hydrogel phase; The obtained hydrogel phase and oil gel phase are mixed, emulsified at high shear speed, and then cooled to room temperature in an ice-water bath to obtain a two-phase gel; Preparation of chocolate: Heat cocoa butter until melted, add cocoa powder, powdered sugar, and soy lecithin, mix well, and ball mill. Add biphasic gel and continue ball milling to obtain a mixed liquid. The mixed liquid is subjected to temperature adjustment, cooled and demoulded to obtain chocolate.

2. The method according to claim 1, wherein: The emulsifier is one or more of monoglyceride, mono- and diglyceride, and polyglycerol ricinoleate; The amount of the emulsifier added is 1 to 10 wt % of the oil phase.

3. The method according to claim 1 or 2, wherein: The solid fat is one or more of cocoa butter equivalent, lauric acid cocoa butter substitute and non-lauric acid cocoa butter substitute; The edible vegetable oil is one or more of soybean oil, peanut oil, corn oil, coconut oil, sunflower oil, rapeseed oil, rice bran oil, olive oil, cottonseed oil, almond oil, tea seed oil, and sesame oil; The ratio of the edible vegetable oil to the solid fat is (1-3):

1.

4. The method according to claim 1, wherein: The heating and stirring process comprises a heating temperature of 75 to 90° C. and a stirring time of 30 to 60 minutes.

5. The method according to claim 1, wherein: The dietary fiber is one or more of citrus fiber, polydextrose, inulin and isomaltooligosaccharide; The dietary fiber is added in an amount of 1 to 4 wt% of the hydrogel phase; The cooling process is carried out with ice water at a temperature of 2±2° C. and a cooling time of 10 to 30 minutes.

6. The method according to claim 1 or 5, wherein: The hydrogel phase and the oleogel phase are mixed, wherein the amount of the oleogel phase added is 20 to 50 wt%, to obtain an O / W type two-phase gel; The amount of oil phase added is 60-80 wt% to obtain a W / O type two-phase gel; The addition amount of the oil phase was 55 wt %, and a bicontinuous two-phase gel was obtained; The shear emulsification has a rotation speed of 5000 to 10000 rpm and a time of 1 to 4 minutes.

7. The method according to claim 6, wherein: Calculated by mass percentage of the raw materials, the cocoa butter accounts for 20-40%, the cocoa powder accounts for 25-35%, the powdered sugar accounts for 25-35%, the two-phase gel accounts for 10-30%, and the soy lecithin accounts for 0.1-1%.

8. The method according to claim 1 or 7, wherein: The ball milling is carried out in a planetary ball mill for 6 to 8 hours.

9. The method according to claim 8, wherein: The temperature adjustment treatment is to first heat the feed liquid to 45-50°C, then cool it to 27-28°C, and then heat it to 31-32°C.

10. A chocolate product having high heat resistance, blooming resistance, high dietary fiber and low saturated fatty acid prepared by the method according to any one of claims 1 to 9.

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