Compound natural agglomeration cake with improved preservation effect and preparation method thereof

Abstract

The application provides a compound natural agglilao cake with improved preservation effect and a preparation method thereof. The agglilao cake comprises base raw materials and embedded compound natural antioxidants. The base raw materials comprise agglilao, walnuts, sesame, rock sugar and yellow rice wine. The embedded compound natural antioxidants comprise core materials and wall materials embedding the core materials. The core materials comprise tea polyphenol, white tomato extract and roselle extract. The wall materials comprise gum arabic and malt dextrin. The tea polyphenol, white tomato extract and roselle extract are compounded according to a specific mass ratio, which can comprehensively play the roles of different natural antioxidant components, can not only inhibit the oxidation and rancidity of oil in the agglilao cake, but also can improve the moisture stability of the agglilao cake during storage, delay the texture hardening of the agglilao cake during storage, effectively prolong the shelf life of the agglilao cake and improve the quality stability of the agglilao cake.

Description

Technical Field

[0001] This invention belongs to the field of food processing technology, and in particular relates to a compound natural donkey-hide gelatin cake with improved preservation effect and its preparation method. Background Technology

[0002] Ejiao cake is a traditional tonic food made primarily from donkey-hide gelatin (Ejiao), along with auxiliary ingredients such as walnuts, sesame seeds, rock sugar, and rice wine. It is popular among consumers for its effects of nourishing yin and blood, and beautifying the skin. However, several quality deterioration issues exist during the processing and storage of Ejiao cake, limiting its shelf life and quality stability.

[0003] First, the walnuts and sesame seeds in donkey-hide gelatin cake are rich in unsaturated fatty acids, which are prone to oxidative rancidity during storage. Walnuts contain over 90% unsaturated fatty acids, making them susceptible to oxidative rancidity due to light, heat, and oxygen, resulting in unpleasant odors and reduced nutritional value. Sesame seeds, another key ingredient, face similar issues.

[0004] Secondly, during storage, donkey-hide gelatin cake also suffers from decreased water activity and hardening of texture. After long-term storage, the surface and internal moisture evaporates as storage time increases, leading to dehydration, hardening, and difficulty in swallowing.

[0005] To inhibit oil oxidation and quality deterioration in donkey-hide gelatin cake, some studies have attempted to add antioxidants. Vitamin C is a common additive, and its addition can improve the antioxidant properties of the cake to some extent. However, the antioxidant effect of a single antioxidant is relatively limited. Natural antioxidants are substances with antioxidant activity extracted from natural plants and animals or their metabolites, such as polyphenols, flavonoids, and vitamins. However, when using a single antioxidant, its structural uniformity may limit its antioxidant activity. Furthermore, natural active ingredients such as tea polyphenols are easily affected by high temperatures during the heat processing of donkey-hide gelatin cake, leading to the loss of active ingredients and a decrease in antioxidant effect.

[0006] In summary, existing donkey-hide gelatin cake products suffer from quality deterioration during storage, including oil oxidation and rancidity, decreased water activity, and hardening of texture. There is an urgent need to develop a donkey-hide gelatin cake product that can effectively inhibit these problems. Summary of the Invention

[0007] In view of this, the present invention aims to propose a compound natural donkey-hide gelatin cake with improved preservation effect and its preparation method. Through the synergistic effect of the compound natural antioxidants, the preservation effect of donkey-hide gelatin cake is improved, the shelf life is extended, and the quality stability is improved.

[0008] To achieve the above objectives, the technical solution of the present invention is implemented as follows: In a first aspect, the present invention provides an encapsulated compound natural antioxidant composition suitable for donkey-hide gelatin cake, wherein the encapsulated compound natural antioxidant comprises a core material and a wall material encapsulating the core material, wherein the mass ratio of the core material to the wall material is 1:2 to 8, for example, it can be any one of 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8 or a range between any two values; wherein the core material comprises tea polyphenols, white tomato extract and prickly pear extract, and the mass ratio of tea polyphenols, white tomato extract and prickly pear extract in the core material is 1:0.25 to 1.5:0.75 to 3.

[0009] Furthermore, the mass ratio of tea polyphenols, white tomato extract, and prickly pear extract in the core material is 1:0.5~1:1~2.

[0010] Further, the wall material includes gum arabic and maltodextrin; preferably, the mass ratio of gum arabic to maltodextrin in the wall material is 1:1 to 4, for example, it can be any one of 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4 or a range between any two values.

[0011] Furthermore, the encapsulated compound natural antioxidant is obtained by homogenizing and spray drying a liquid containing the core material and the wall material.

[0012] In a second aspect, the present invention provides a donkey-hide gelatin cake containing the encapsulated compound natural antioxidants described in the first aspect, wherein the donkey-hide gelatin cake comprises basic raw materials and encapsulated compound natural antioxidants, wherein the mass of the encapsulated compound natural antioxidants is 1% to 5% of the basic raw materials.

[0013] Furthermore, the basic ingredients include donkey-hide gelatin, walnuts, sesame seeds, rock sugar, and rice wine.

[0014] Furthermore, the basic raw materials include, by weight, 50-80 parts of donkey-hide gelatin, 20-30 parts of walnuts, 15-25 parts of sesame seeds, 5-10 parts of rock sugar, and 10-15 parts of rice wine.

[0015] Thirdly, the present invention provides a method for preparing donkey-hide gelatin cake as described in the second aspect, the method comprising the following steps: S1. Mix gum arabic, maltodextrin and water until completely dissolved to obtain a wall material solution. Mix tea polyphenols, white tomato extract and prickly pear extract and add them to the wall material solution to obtain a liquid. Homogenize the liquid and spray dry it to obtain an encapsulated compound natural antioxidant. S2. After crushing the donkey-hide gelatin, add it to the rice wine and heat until it is completely dissolved to obtain donkey-hide gelatin rice wine; S3. After preheating the donkey-hide gelatin rice wine, add rock sugar until completely dissolved, then add crushed walnuts and sesame seeds, heat and stir to cook, and finally add the encapsulated compound natural antioxidant, mix evenly, and obtain the donkey-hide gelatin cake.

[0016] Further, in step S1, the mass fraction of solids in the liquid is 10% to 30%, for example, it can be any one of 10%, 15%, 20%, 25%, 30% or a range between any two values; Preferably, in step S1, the rotation speed of the homogenization process is 5000~12000 rpm, for example, it can be any one value or a range between any two values ​​from 5000 rpm, 6000 rpm, 7000 rpm, 8000 rpm, 9000 rpm, 10000 rpm, 11000 rpm, and 12000 rpm, and the homogenization time is 3~10 min, for example, it can be any one value or a range between any two values ​​from 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min, and 10 min; Preferably, in step S1, the inlet air temperature of the spray dryer is 120~180℃, for example, it can be any one or any two values ​​between 120℃, 130℃, 140℃, 150℃, 160℃, 170℃, and 180℃; the outlet air temperature is 60~90℃, for example, it can be any one or any two values ​​between 60℃, 70℃, 80℃, and 90℃; and the feed rate is 5~20mL / min, for example, it can be any one or any two values ​​between 5mL / min, 8mL / min, 10mL / min, 12mL / min, 15mL / min, 18mL / min, and 20mL / min.

[0017] Furthermore, in step S2, the heating temperature is 80~90℃, for example, it can be any one of 80℃, 82℃, 85℃, 88℃, 90℃ or a range between any two values.

[0018] Furthermore, in step S3, the preheating temperature is 80~90℃, for example, it can be any one of 80℃, 82℃, 85℃, 88℃, and 90℃ or a range between any two values; Preferably, in step S3, the heating and stirring cooking temperature is 60~70℃, for example, it can be any one of 60℃, 62℃, 65℃, 68℃, 70℃ or a range between any two values, and the heating and stirring cooking time is 15~20min, for example, it can be any one of 15min, 16min, 17min, 18min, 19min, 20min or a range between any two values; Preferably, in step S3, the encapsulated compound natural antioxidant is added 3-5 minutes before the end of heating, stirring and cooking, at a temperature of 55-70°C, for example, any one of 55°C, 58°C, 60°C, 62°C, 65°C, 68°C, 70°C or a range between any two of these values.

[0019] Furthermore, step S3 also includes the steps of shaping, cooling, cutting and packaging the donkey-hide gelatin cake; Preferably, the cooling temperature is 4~6℃ and the cooling time is 2~4h; Preferably, the packaging is vacuum-sealed packaging with a packaging pressure of -0.1 to -0.08 MPa and a packaging temperature of 100 to 120°C.

[0020] Fourthly, the present invention provides the application of the encapsulated compound natural antioxidants as described in the first aspect in the preparation of donkey-hide gelatin cake, the application including improving the taste and / or storage quality of donkey-hide gelatin cake; Preferably, the application includes at least one of the following: (1) Application in inhibiting the oxidative rancidity of oils in donkey-hide gelatin cake; (2) Application in improving the moisture stability of donkey-hide gelatin cake during storage; (3) Application in delaying the textural hardening of donkey-hide gelatin cake during storage.

[0021] Furthermore, the mass ratio of the core material to the wall material is 1:2 to 8, for example, it can be any one of 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8 or a range between any two values.

[0022] Furthermore, the mass ratio of tea polyphenols, white tomato extract, and prickly pear extract in the core material is 1:0.25~1.5:0.75~3; preferably 1:0.5~1:1~2.

[0023] Furthermore, the mass ratio of gum arabic to maltodextrin is 1:1 to 4, for example, it can be any one of 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4 or a range between any two values.

[0024] Compared with existing technologies, the donkey-hide gelatin cake containing encapsulated compound natural antioxidants and its preparation method described in this invention have the following advantages: (1) The present invention combines tea polyphenols, white tomato extract and prickly pear extract in a specific mass ratio, which can comprehensively exert the effects of different natural antioxidant components. It can not only inhibit the oxidative rancidity of oil in donkey-hide gelatin cake, but also improve the moisture stability of donkey-hide gelatin cake during storage, delay the hardening of texture during the storage process, effectively extend the shelf life of donkey-hide gelatin cake, and improve the quality stability of donkey-hide gelatin cake.

[0025] (2) In this invention, gum arabic and maltodextrin are used as composite wall materials. The compound natural antioxidants are encapsulated by homogenization and spray drying, which can reduce the direct contact between active ingredients and heat, oxygen and food matrix, improve the stability of compound antioxidants during high-temperature processing and storage, and enhance the protective effect of compound natural antioxidants under high-temperature storage conditions.

[0026] (3) The present invention uses tea polyphenols, white tomato extract and prickly pear extract as compound natural antioxidants. All raw materials used are of natural origin, and food-grade common excipients gum arabic and maltodextrin are used as wall materials. The preparation process conditions are clear, which facilitates continuous and large-scale production, while reducing the dependence on synthetic antioxidants. Detailed Implementation

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0028] The present invention will now be described in detail with reference to embodiments.

[0029] The basic raw materials used in the preparation of donkey-hide gelatin cake in the following examples and comparative examples include: The total weight of the basic ingredients is 130g, consisting of 65g donkey-hide gelatin, 25g walnuts, 20g sesame seeds, 8g rock sugar, and 12g rice wine.

[0030] The preparation method of donkey-hide gelatin cake is as follows: (1) Crush the donkey-hide gelatin, soak it in rice wine for 3 hours, and then heat it at 85°C to fully dissolve the donkey-hide gelatin and obtain a donkey-hide gelatin rice wine solution; (2) Roast the walnuts and sesame seeds separately, cool them, and then grind them to obtain walnut powder and sesame powder; (3) Heat the donkey-hide gelatin rice wine solution to 85°C, add rock sugar, and stir until the rock sugar is completely dissolved; then add walnut powder and sesame powder in sequence, and stir and cook for 18 minutes at 65°C and 40 r / min. (4) When the material temperature is 60°C and 4 minutes before the end of cooking, add the corresponding encapsulated natural antioxidant or control material and continue stirring until it is evenly dispersed; (5) Pour the obtained donkey-hide gelatin cake material into the mold, spread it evenly and press it firmly. After cooling at room temperature, refrigerate it at 5°C for 3 hours. (6) Cut the solidified donkey-hide gelatin cake into 8g pieces and vacuum seal it under vacuum conditions of -0.09MPa and sealing temperature of 110℃.

[0031] Example 1

[0032] In this embodiment, the encapsulated natural antioxidants, including tea polyphenols, white tomato extract, and prickly pear extract, are present in a mass ratio of 3:2:5, and these three components together constitute the core material. The mass ratio of the core material to the wall material is 1:5. The wall material is composed of gum arabic and maltodextrin in a mass ratio of 1:3. The specific preparation method includes the following steps: (1) Weigh out 5.00g of tea polyphenols, 3.33g of white tomato extract, 8.34g of prickly pear extract, 20.83g of gum arabic and 62.50g of maltodextrin.

[0033] (2) Add gum arabic and maltodextrin to 400g of water and stir at 50°C to dissolve them to obtain a wall material solution; add tea polyphenols, white tomato extract and prickly pear extract to the wall material solution and homogenize at 8000r / min for 5min to obtain a spray-dried liquid with a solid mass fraction of 20%.

[0034] (3) The spray-dried liquid is spray-dried with an inlet air temperature of 150°C, an outlet air temperature of 75°C, and a feed rate of 10 mL / min to obtain an encapsulated compound natural antioxidant.

[0035] According to the above preparation method for donkey-hide gelatin cake, 3.90g of encapsulated compound natural antioxidants are added to every 130g of basic raw materials to obtain the donkey-hide gelatin cake.

[0036] Example 2

[0037] In this embodiment, the encapsulated natural antioxidants, including tea polyphenols, white tomato extract, and prickly pear extract, are present in a mass ratio of 2:1:2, and these three components together constitute the core material. The mass ratio of the core material to the wall material is 1:2. The wall material is composed of gum arabic and maltodextrin in a mass ratio of 1:1. The specific preparation method includes the following steps: (1) Weigh out 13.33g of tea polyphenols, 6.67g of white tomato extract, 13.33g of prickly pear extract, 33.34g of gum arabic and 33.33g of maltodextrin.

[0038] (2) Add gum arabic and maltodextrin to 566.67g of water and stir at 50°C to dissolve them to obtain a wall material solution; add tea polyphenols, white tomato extract and prickly pear extract to the wall material solution and homogenize at 5000r / min for 3min to obtain a spray-dried liquid with a solid mass fraction of 15%.

[0039] (3) The spray-dried liquid is spray-dried with an inlet air temperature of 130°C, an outlet air temperature of 65°C, and a feed rate of 5 mL / min to obtain an encapsulated compound natural antioxidant.

[0040] Following the above preparation method for donkey-hide gelatin cake, 1.30g of encapsulated compound natural antioxidant was added to every 130g of basic raw materials to obtain the donkey-hide gelatin cake of Example 2.

[0041] Example 3

[0042] In this embodiment, the encapsulated natural antioxidants, including tea polyphenols, white tomato extract, and prickly pear extract, are present in a mass ratio of 1:1:2, and these three components together constitute the core material. The mass ratio of the core material to the wall material is 1:8. The wall material is composed of gum arabic and maltodextrin in a mass ratio of 1:4. The specific preparation method includes the following steps: (1) Weigh out 2.78g of tea polyphenols, 2.78g of white tomato extract, 5.55g of prickly pear extract, 17.78g of gum arabic and 71.11g of maltodextrin.

[0043] (2) Add gum arabic and maltodextrin to 300g of water and stir at 55°C to dissolve them to obtain a wall material solution; add tea polyphenols, white tomato extract and prickly pear extract to the wall material solution and homogenize at 12000r / min for 10min to obtain a spray-dried liquid with a solid mass fraction of 25%.

[0044] (3) The spray-dried liquid is spray-dried with an inlet air temperature of 170°C, an outlet air temperature of 85°C, and a feed rate of 15 mL / min to obtain an encapsulated compound natural antioxidant.

[0045] Following the above preparation method for donkey-hide gelatin cake, 5.85g of encapsulated compound natural antioxidants were added to every 130g of basic raw materials to obtain the donkey-hide gelatin cake of Example 3.

[0046] Comparative Example 1 The difference from Example 1 is that no compound natural antioxidant was added to the donkey-hide gelatin cake prepared in this comparative example. The remaining steps are the same as in Example 1, and the donkey-hide gelatin cake of Comparative Example 1 is obtained.

[0047] Comparative Example 2 The difference from Example 1 is that no encapsulated natural antioxidants were added in this comparative example. Instead, a control material was added. The control material was prepared as follows: gum arabic and maltodextrin were added to water at a mass ratio of 1:3 and stirred and dissolved at 50°C. The control material was prepared under the spray drying conditions of Example 1 without the addition of tea polyphenols, white tomato extract and prickly pear extract.

[0048] According to the above preparation method of donkey-hide gelatin cake, 3.90g of the control material was added to every 130g of basic raw materials to obtain the donkey-hide gelatin cake of Comparative Example 2.

[0049] Comparative Example 3 The difference from Example 1 is that the preparation method of the encapsulated compound natural antioxidant in this comparative example is as follows: tea polyphenols are used as the sole core material, and white tomato extract and prickly pear extract are not added. The mass ratio of tea polyphenol core material to wall material is 1:5, and the wall material is composed of gum arabic and maltodextrin in a mass ratio of 1:3. The homogenization conditions and spray drying conditions are the same as in Example 1.

[0050] Following the above preparation method for donkey-hide gelatin cake, a compound natural antioxidant containing 0.65g of tea polyphenol core material was added to every 130g of basic raw materials to obtain donkey-hide gelatin cake of Comparative Example 3.

[0051] Comparative Example 4 The difference from Example 1 is that the preparation method of the encapsulated compound natural antioxidant in this comparative example is as follows: white tomato extract is used as the only core material, and tea polyphenols and prickly pear extract are not added. The mass ratio of white tomato extract core material to wall material is 1:5, and the wall material is composed of gum arabic and maltodextrin in a mass ratio of 1:3. The homogenization conditions and spray drying conditions are the same as in Example 1.

[0052] Following the above preparation method for donkey-hide gelatin cake, a compound natural antioxidant containing 0.65g of white tomato extract core material was added to every 130g of basic raw materials to obtain donkey-hide gelatin cake of Comparative Example 4.

[0053] Comparative Example 5 The difference from Example 1 is that the preparation method of the encapsulated compound natural antioxidant in this comparative example is as follows: Prickly pear extract is used as the sole core material, without the addition of tea polyphenols and white tomato extract. The mass ratio of the prickly pear extract core material to the wall material is 1:5, and the wall material is composed of gum arabic and maltodextrin in a mass ratio of 1:3. The homogenization and spray drying conditions are the same as in Example 1.

[0054] Following the above preparation method for donkey-hide gelatin cake, a compound natural antioxidant containing 0.65g of prickly pear extract core material is added to every 130g of basic raw materials to obtain donkey-hide gelatin cake of Comparative Example 5.

[0055] Comparative Example 6 The difference from Example 1 is that the preparation method of the control material used in this comparative example is as follows: (1) According to the mass ratio of tea polyphenols, white tomato extract and prickly pear extract of 3:2:5, weigh 0.195g of tea polyphenols, 0.130g of white tomato extract and 0.325g of prickly pear extract, mix them evenly, and obtain 0.65g of unencapsulated compound natural antioxidant. (2) Add gum arabic and maltodextrin to water at a mass ratio of 1:3 and stir to dissolve at 50°C. Prepare blank wall material according to the spray drying conditions of Example 1 without adding tea polyphenols, white tomato extract and prickly pear extract. (3) 3.25g of blank wall material was physically mixed with 0.65g of unencapsulated compound natural antioxidant to obtain control material.

[0056] According to the above preparation method of donkey-hide gelatin cake, 3.90g of the control material was added to every 130g of basic raw materials to obtain the donkey-hide gelatin cake of Comparative Example 6.

[0057] Comparative Example 7 The difference from Example 1 is that the preparation method of the encapsulated compound natural antioxidant in this comparative example is as follows: the core material is composed of tea polyphenols and white tomato extract, without adding prickly pear extract; the mass ratio of tea polyphenols to white tomato extract is 3:2, the total amount of core material added is 0.65g, and the mass ratio of core material to wall material, wall material composition, homogenization conditions and spray drying conditions are the same as in Example 1.

[0058] Following the above preparation method for donkey-hide gelatin cake, 3.90g of encapsulated compound natural antioxidants were added to every 130g of basic raw materials to obtain donkey-hide gelatin cake of Comparative Example 7.

[0059] Comparative Example 8 The difference from Example 1 is that the preparation method of the encapsulated compound natural antioxidant in this comparative example is as follows: the core material is composed of tea polyphenols and prickly pear extract, without adding white tomato extract; the mass ratio of tea polyphenols to prickly pear extract is 3:5, the total amount of core material added is 0.65g, and the mass ratio of core material to wall material, wall material composition, homogenization conditions and spray drying conditions are the same as in Example 1.

[0060] Following the above preparation method for donkey-hide gelatin cake, 3.90g of encapsulated compound natural antioxidants were added to every 130g of basic raw materials to obtain donkey-hide gelatin cake of Comparative Ratio 8.

[0061] Comparative Example 9 The difference from Example 1 is that the preparation method of the encapsulated compound natural antioxidant in this comparative example is as follows: the core material is composed of white tomato extract and prickly pear extract, without the addition of tea polyphenols; the mass ratio of white tomato extract to prickly pear extract is 2:5, the total amount of core material added is 0.65g, and the mass ratio of core material to wall material, wall material composition, homogenization conditions and spray drying conditions are the same as those in Example 1.

[0062] Following the above preparation method for donkey-hide gelatin cake, 3.90g of encapsulated compound natural antioxidants were added to every 130g of basic raw materials to obtain donkey-hide gelatin cake of Comparative Example 9.

[0063] Comparative Example 10 The difference from Example 1 is that the preparation method of the encapsulated compound natural antioxidant in this comparative example is as follows: the mass ratio of tea polyphenols, white tomato extract, and prickly pear extract is 8:1:1, and the total amount of core material added is still 0.65g. The mass ratio of core material to wall material, wall material composition, homogenization conditions, and spray drying conditions are all the same as in Example 1.

[0064] Following the above method for preparing donkey-hide gelatin cake, 3.90g of encapsulated compound natural antioxidants are added to every 130g of basic raw materials to obtain a comparison ratio of 10 donkey-hide gelatin cake.

[0065] Performance testing The following performance tests were conducted on the donkey-hide gelatin cakes prepared in Example 1 and Comparative Examples 1-10: (1) Water activity determination: The water activity value of the donkey-hide gelatin cake was directly measured at the corresponding storage temperature using a water activity meter. Each sample was measured in parallel 3 times and the average value was taken.

[0066] (2) Texture determination: The TA~XT plus physical property tester was used with the following parameters: test rate 2mm / s, return rate 2mm / s, deformation 75%, time interval between two compressions 5s, and compression probe was a P35mm cylindrical probe. The hardness and adhesiveness of the donkey-hide gelatin cake were measured. Each sample was measured 5 times and the average value was taken.

[0067] (3) Determination of lipid oxidation index: Acid value: determined according to the method in GB 5009.229~2016 "National Food Safety Standard - Determination of Acid Value in Food"; Peroxide value: determined according to the method of GB 5009.227~2016 "National Food Safety Standard for Determination of Peroxide Value in Food".

[0068] Comparative Example 1 was used as a blank control without added antioxidants. Comparative Examples 3, 4 and 5 were used as groups where tea polyphenols, white tomato extract and prickly pear extract were used alone, respectively. Example 1 was used as a compound group.

[0069] The inhibition rate of lipid oxidation in each treatment group was calculated using the following formula:

[0070] In the formula, C0 is the acid value or peroxide value of Comparative Example 1, and C i This refers to the acid value or peroxide value of the corresponding treatment group.

[0071] The inhibition rates of the three antioxidants were calculated using the following formula:

[0072] The synergy index is calculated using the following formula:

[0073] Among them, I T I W and I R The inhibition rates of tea polyphenols, white tomato extract, and prickly pear extract when used alone were respectively, I min The measured inhibition rate is shown in Example 1.

[0074] Test Results Water activity reflects the binding and migration state of water in donkey-hide gelatin cake and is closely related to the product texture and storage stability. As shown in Table 1, the water activity of each treatment group decreased with the extension of storage time, and the higher the storage temperature, the greater the decrease. After 70 days of storage at 25℃~50℃, the water activity of Example 1 was higher than that of the comparative examples, proving that the donkey-hide gelatin cake prepared by this invention has better water retention capacity. After 70 days of storage at 25℃, the water activity of Example 1 was the highest, reaching 0.658, which was 5.11% higher than that of Comparative Example 1 without added antioxidants; under 37℃ conditions, the water activity of Example 1 after 70 days of storage was 0.549, which was 17.31% higher than that of Comparative Example 1 (0.468), indicating that Example 1 has good water retention capacity under medium temperature conditions.

[0075] After 70 days of accelerated storage at 50℃, the water activity of Example 1 was 0.453, an increase of 19.53% compared to 0.379 in Comparative Example 1. Comparative Examples 3-5, each with a single encapsulated antioxidant, showed lower water activities than Example 1, indicating that the compound system had a significant synergistic effect compared to a single antioxidant, and its water activity retention was superior. Comparative Example 6, using an unencapsulated compound antioxidant, had a water activity of 0.424, lower than Example 1, indicating that spray drying encapsulation helps improve the stability of the compound antioxidant during high-temperature processing and storage. The binary compound groups of Comparative Examples 7-9 and the non-preferred ternary compound group of Comparative Example 10 both showed lower water activities than Example 1, indicating that the combined use of the three antioxidants and their compounding ratios affect the water retention effect of the donkey-hide gelatin cake. This invention, through the synergistic effect of the three antioxidants and the selection of the compounding ratio, significantly improves the water retention capacity of the donkey-hide gelatin cake.

[0076] Table 1. Water activity of donkey-hide gelatin cakes from different treatment groups after 70 days of storage at different temperatures.

[0077] As shown in Table 2, the hardness of each group of donkey-hide gelatin cakes increased with prolonged storage time, and the increase in hardness was more significant at higher temperatures, indicating that moisture migration and protein cross-linking accelerate product hardening. The hardness of Example 1 after 70 days of storage at 25℃, 37℃, and 50℃ were 503.65g, 644.74g, and 2409.16g, respectively, which were 24.90%, 44.61%, and 23.63% lower than that of Comparative Example 1 without added antioxidants, indicating that the optimal ratio of encapsulated compound antioxidants can effectively delay the hardening of donkey-hide gelatin cakes. After 70 days of storage at 50℃, the average hardness of Example 1 was 23.31% lower than that of Comparative Examples 3-5 with single antioxidants, 14.35% lower than that of Comparative Example 6 without encapsulated compound antioxidants, and 5.73% lower than that of Comparative Examples 7-9 with binary compound antioxidants. This invention demonstrates that the effect of using a combination of three antioxidants is superior to that of a single antioxidant system. Furthermore, the combined use of the three antioxidants and their compounding ratio both affect the textural stability of the donkey-hide gelatin cake. Through the synergistic effect of the three antioxidants and the selection of the compounding ratio, this invention significantly improves the textural stability of the donkey-hide gelatin cake. At the same time, spray drying and encapsulation also help maintain the textural stability of the donkey-hide gelatin cake.

[0078] Table 2. Texture characteristics (hardness / g) of donkey-hide gelatin cakes from different treatment groups stored at different temperatures for 70 days.

[0079] The walnuts and sesame seeds in donkey-hide gelatin cake are rich in unsaturated fatty acids, which are prone to oxidative rancidity during storage. As shown in Table 3, the acid value and peroxide value of each group gradually increased with increasing storage temperature, but Example 1 remained the lowest. After 70 days of storage at 25℃, the acid value and peroxide value of Example 1 were 1.31 mg KOH / g and 0.069 g / 100g, respectively, which were 21.56% and 38.39% lower than those of Comparative Example 1 without added antioxidants. At 50℃, the two indicators of Example 1 were 1.64 mg KOH / g and 0.103 g / 100g, respectively, which were 24.77% and 46.35% lower than those of Comparative Example 1, indicating that it still has a good antioxidant effect under high temperature conditions. Comparative Examples 3-5 were single antioxidant groups, and their acid value and peroxide value were higher than those of Example 1, indicating that the compound system has a significant synergistic effect compared to the single antioxidant, and its ability to maintain acid value and peroxide value is better than that of the single antioxidant. Comparative Example 6 used an unencapsulated compound antioxidant. At 50°C, the acid value and peroxide value were 1.86 mg KOH / g and 0.135 g / 100 g, respectively, both higher than those of Example 1. This indicates that spray drying encapsulation helps improve the processing and storage stability of the compound antioxidant. It also shows that the combination of the three antioxidants and their mass ratio have an important influence on inhibiting the oxidation of oils in donkey-hide gelatin cake. Through the synergistic effect of the three antioxidants and the selection of the compound ratio, the antioxidant of this invention significantly improves the anti-oil oxidation ability of donkey-hide gelatin cake.

[0080] Table 3. Oil oxidation indicators of donkey-hide gelatin cakes from different treatment groups stored at different temperatures for 70 days.

[0081] As shown in Table 4, the SI values ​​of Example 1 were all greater than 1 at different storage temperatures, with the SI values ​​corresponding to acid values ​​ranging from 2.609 to 2.983 and the SI values ​​corresponding to peroxide values ​​ranging from 2.042 to 2.361. The actual oxidation inhibition rates of Example 1 were significantly higher than the theoretical summation calculated using the three single antioxidants in a 3:2:5 ratio, indicating that the combination of tea polyphenols, white tomato extract, and prickly pear extract has a synergistic inhibitory effect on the oxidation of oils in donkey-hide gelatin cake. As the storage temperature increased, the compound system maintained a high SI value, indicating that it still has a good synergistic antioxidant effect under high-temperature storage conditions.

[0082] Table 4. Apparent synergistic index of compound natural antioxidants on the oxidation of oils in donkey-hide gelatin cake

[0083] The embodiments described above are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

Claims

1. A compound natural antioxidant composition suitable for encapsulating donkey-hide gelatin cake, characterized in that, The encapsulated compound natural antioxidant includes a core material and a wall material encapsulating the core material, wherein the mass ratio of the core material to the wall material is 1:2~8; the core material includes tea polyphenols, white tomato extract and prickly pear extract, wherein the mass ratio of tea polyphenols, white tomato extract and prickly pear extract in the core material is 1:0.25~1.5:0.75~3.

2. The encapsulated compound natural antioxidant composition according to claim 1, characterized in that, The mass ratio of tea polyphenols, white tomato extract, and prickly pear extract in the core material is 1:0.5~1:1~2.

3. The encapsulated compound natural antioxidant composition according to claim 1, characterized in that, The wall material comprises gum arabic and maltodextrin; preferably, the mass ratio of gum arabic to maltodextrin in the wall material is 1:1 to 4.

4. The encapsulated compound natural antioxidant composition according to claim 1, characterized in that, The encapsulated compound natural antioxidant is obtained by homogenizing and spray drying a liquid containing the core material and wall material.

5. A type of donkey-hide gelatin cake containing the encapsulated compound natural antioxidants as described in any one of claims 1-4, characterized in that, The donkey-hide gelatin cake includes basic raw materials and encapsulated compound natural antioxidants, wherein the mass of the encapsulated compound natural antioxidants is 1% to 5% of the basic raw materials.

6. The donkey-hide gelatin cake according to claim 5, characterized in that: The basic ingredients include donkey-hide gelatin, walnuts, sesame seeds, rock sugar, and rice wine; preferably, the basic ingredients include, by weight, 50-80 parts donkey-hide gelatin, 20-30 parts walnuts, 15-25 parts sesame seeds, 5-10 parts rock sugar, and 10-15 parts rice wine.

7. The method for preparing donkey-hide gelatin cake as described in claim 5 or 6, characterized in that, The preparation method includes the following steps: S1. Mix gum arabic, maltodextrin and water until completely dissolved to obtain a wall material solution. Mix tea polyphenols, white tomato extract and prickly pear extract and add them to the wall material solution to obtain a liquid. Homogenize the liquid and spray dry it to obtain an encapsulated compound natural antioxidant. S2. After crushing the donkey-hide gelatin, add it to the rice wine and heat until it is completely dissolved to obtain donkey-hide gelatin rice wine; S3. After preheating the donkey-hide gelatin rice wine, add rock sugar until completely dissolved, then add crushed walnuts and sesame seeds, heat and stir to cook, and finally add the encapsulated compound natural antioxidant, mix evenly, and obtain the donkey-hide gelatin cake.

8. The preparation method according to claim 7, characterized in that: In step S1, the mass fraction of solids in the liquid is 10%~30%; Preferably, in step S1, the rotation speed of the homogenization process is 5000~12000 rpm, and the homogenization time is 3~10 min; Preferably, in step S1, the inlet air temperature of the spray dryer is 120~180℃, the outlet air temperature is 60~90℃, and the feed rate is 5~20mL / min.

9. The preparation method according to claim 7, characterized in that: In step S3, the preheating temperature is 80~90℃; Preferably, in step S3, the heating and stirring cooking temperature is 60~70℃, and the heating and stirring cooking time is 15~20min; Preferably, in step S3, the encapsulated compound natural antioxidant is added 3-5 minutes before the end of heating, stirring and cooking, at a temperature of 55-70°C.

10. The application of the encapsulated compound natural antioxidant as described in any one of claims 1-4 in the preparation of donkey-hide gelatin cake, characterized in that, The applications include improving the taste and / or storage quality of donkey-hide gelatin cake; Preferably, the application includes at least one of the following: (1) Application in inhibiting the oxidative rancidity of oils in donkey-hide gelatin cake; (2) Application in improving the moisture stability of donkey-hide gelatin cake during storage; (3) Application in delaying the textural hardening of donkey-hide gelatin cake during storage.

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