Compound water retention agent for food and preparation method of compound water retention agent

Abstract

The invention discloses a compound water retention agent for food and a preparation method of the compound water retention agent, and mainly relates to the technical field of food additives. Compared with the prior art, sodium tripolyphosphate and sodium dihydrogen phosphate are used as composite phosphates, and are matched with the coordination effect of the enzyme preparation, glycerol, microcapsules, sodium carbonate, sodium citrate, maltodextrin, protein additive and thickening agent to maintain high water-retaining property, elasticity and tenderness. According to the invention, microcapsules prepared by taking glucomannan and the like as wall materials, taking casein as an emulsifier and taking grease core materials are also added, when the meat food is subjected to deep-frying processing, grease slowly released by the microcapsules can permeate into a meat protein network to weaken the cross-linking strength among protein molecules, and other components such as xanthan gum, guar gum and the like are matched, so that the meat food has a good deep-frying effect. Therefore, the hardness of the meat product is reduced, and high elasticity and tenderness are kept.

Description

Technical Field

[0001] The present invention relates to the technical field of food additives and foods, in particular to a compound water retaining agent for food and a preparation method thereof. Background Art

[0002] Compound moisture retainers for food are a type of compound food additive developed to maintain the moisture content and improve the texture and taste of easily dehydrated foods such as meat, aquatic products, and eggs. After adding compound moisture retainers to meat products, the water loss during storage and processing such as heating, freezing, and drying is reduced, thereby maintaining the water retention, juiciness, tenderness, and elasticity of the food, and preventing the meat from hardening and drying out. During the frying process of meat products, high temperatures will cause the water in the meat tissue to evaporate rapidly, making the meat dry and hard due to water loss; at the same time, meat protein will undergo drastic denaturation at high temperatures, and intermolecular cross-linking will intensify, resulting in a decrease in meat elasticity and tenderness. It may also form a hard shell due to excessive combination of surface starch and oil, resulting in an unpleasant taste of being hard on the outside and dry on the inside, seriously affecting product quality.

[0003] Prior art approaches to improving water retention and meat frying primarily rely on adjusting the formulation of humectants and optimizing the process. For example, emulsifiers, stabilizers, and humectants are added to enhance the water retention and elasticity of meat products, reduce water loss, and prevent protein denaturation, thereby improving the tenderness, elasticity, and texture of the meat. Alternatively, adjustments to frying parameters, such as staged frying and low-temperature frying, can reduce water loss, mitigate protein denaturation, and avoid a tough exterior and dry interior, thereby improving the tenderness, elasticity, and texture of the meat.

[0004] The present invention provides a compound water-retaining agent for food and a preparation method thereof, and aims to improve the water-retaining property of meat food and to increase the elasticity and reduce the hardness of meat food during frying.

[0005] CN110338395A discloses a compound moisture-retaining agent and its preparation and application, which includes the following components: sodium pyrophosphate, trisodium phosphate, disodium dihydrogen pyrophosphate, sodium tripolyphosphate, sodium hexametaphosphate, sodium bicarbonate, sodium citrate, and sodium carbonate. The compound moisture-retaining agent allows beef to maintain its elasticity and taste after being frozen in a -18°C cold storage, but does not involve the effect of increasing elasticity and reducing hardness of meat food during frying, and its applicable scenarios are relatively limited.

[0006] CN119632179A discloses a compound moisture retainer, boiled pork tripe and a preparation method thereof, comprising the following components: trisodium phosphate, sodium pyrophosphate, sodium tripolyphosphate, sodium bicarbonate, sodium carbonate, sodium citrate, glycine, citric acid and trehalose, which can effectively reduce ripening loss and thawing loss without any peculiar smell. This invention mainly aims at optimizing ripening loss and thawing loss, but does not clearly solve the problem of maintaining elasticity and hardness of meat food during processing. Summary of the Invention

[0007] In view of the above-mentioned defects of the prior art, the technical problem to be solved by the present invention is to improve the water retention of meat food and the elasticity of meat food during the frying process and reduce the hardness.

[0008] To achieve the above object, the present invention provides a compound water-retaining agent for food and a preparation method thereof.

[0009] The preparation method of the composite water-retaining agent for food comprises the following steps, calculated in parts by weight:

[0010] (1) Add 0.5-1.5 parts of enzyme preparation to 15-25 parts of water to obtain an enzyme preparation aqueous solution;

[0011] (2) Add 70-80 parts of sodium tripolyphosphate, 15-25 parts of enzyme preparation aqueous solution, 4-6 parts of sodium dihydrogen phosphate, 2-6 parts of glycerol, 4-6 parts of microcapsules, 0.5-1.5 parts of sodium carbonate, and 0.5-1.5 parts of sodium citrate to 80-120 parts of water, and stir at room temperature for 0.5-1 hour; add 4-6 parts of maltodextrin, 4-6 parts of protein additive, and 4-6 parts of thickener, stir at 35-40°C for 0.5-1 hour, cool to room temperature, grind through a 400-600 mesh sieve; finally, granulate by a centrifugal spray granulator, and obtain the compound water-retaining agent for food after drying.

[0012] The enzyme preparation is a compound of papain, transglutaminase and cellulase.

[0013] The thickener is one or more of xanthan gum, guar gum, locust bean gum and carrageenan.

[0014] The protein additive is one or more of soy protein isolate, pea protein, and peanut protein.

[0015] The preparation method of the microcapsules is as follows, in parts by weight:

[0016] 0.5-0.8 parts of casein are added to 10-15 parts of water and stirred at 85-95° C. for 0.5-1 hour, 2-4 parts of glucomannan and 1-2 parts of lactose are added and stirred for 0.5-1 hour, and then stirred at 85-95° C. for 3-5 hours; the solution is cooled to 45-55° C., 2-4 parts of oil core material are added and homogenized to obtain an oil-in-water solution; and the solution is dried in a spray dryer to obtain the microcapsules.

[0017] The oil core material is one or more of soybean oil, algae oil, sweet almond oil, and conjugated linoleic acid.

[0018] Further preferably, the oil core material is a complex of sweet almond oil and conjugated linoleic acid, wherein the conjugated linoleic acid accounts for 1-10% of the total mass of the core material, and the balance is sweet almond oil.

[0019] The present invention uses sodium tripolyphosphate and sodium dihydrogen phosphate as composite phosphates, which chelate metal ions in meat to stretch protein chains, expose more hydrophilic groups, and at the same time increase the ionic strength of the system and expand the water holding space of the protein network. Papain, transglutaminase, and cellulase are used as composite enzyme preparations. Papain hydrolyzes the loose structure of meat protein to facilitate the penetration of water and other components; transglutaminase catalyzes protein cross-linking to build a stable three-dimensional network; cellulase decomposes connective tissue. The three synergistically optimize the water holding and texture basis of meat tissue. Glycerol has strong hydrophilicity and can lock free water in meat by forming hydrogen bonds with water molecules, reducing water evaporation during processing and helping to improve water retention; sodium carbonate can promote the dissociation of phosphates and improve their chelation efficiency; sodium citrate can alleviate the oxidation reaction of the system and protect the activity of other components; protein additives are added to fill the network gaps and enhance water holding capacity; thickeners are added to adjust the viscosity of the system, and at the same time play a bonding role during the drying and granulation process to improve product stability.

[0020] The microcapsules added in the present invention use a composite of glucomannan and lactose as the microcapsule wall material, casein as the emulsifier, and oil as the core material. When the meat food is fried, the oil slowly released from the microcapsules can penetrate into the meat protein network, weakening the cross-linking strength between protein molecules. In combination with other components such as xanthan gum and guar gum, the hardness of the meat product is reduced, and the high elasticity and tenderness are maintained.

[0021] Beneficial effects of the present invention:

[0022] Compared to existing technologies, this invention utilizes sodium tripolyphosphate and sodium dihydrogen phosphate as composite phosphates, along with enzyme preparations, glycerin, microcapsules, sodium carbonate, sodium citrate, maltodextrin, protein additives, and thickeners to achieve high water retention, elasticity, and tenderness. The invention also incorporates microcapsules made with glucomannan as a wall material, casein as an emulsifier, and oil as a core material. During the frying process, the oil slowly released from the microcapsules penetrates the meat protein network, weakening the cross-linking strength between protein molecules. Combined with other ingredients such as xanthan gum and guar gum, this reduces the hardness of the meat product while maintaining high elasticity and tenderness. DETAILED DESCRIPTION

[0023] The parameters of the specific chemical substances used in the examples are derived from the following sources:

[0024] Glucomannan: The manufacturer is Anhui Zhonghong Bioengineering Co., Ltd., and the product number is 214563.

[0025] Soybean oil: The manufacturer is Hubei Junrui Biotechnology Co., Ltd., and the product number is JR5539.

[0026] Algal oil: The manufacturer is Hefei Hongrui Biotechnology Co., Ltd., and the product number is 97.

[0027] Sweet almond oil: The manufacturer is Hubei Junrui Biotechnology Co., Ltd., and the product number is JR8935.

[0028] Papain: The manufacturer is Hefei Hongrui Biotechnology Co., Ltd., with an enzyme activity of 100,000.

[0029] Glutamine transaminase: The manufacturer is Anhui Runtai Biotechnology Co., Ltd., with an enzyme activity of 100,000.

[0030] Cellulase: The manufacturer is Sichuan Huatang Jurui Biotechnology Co., Ltd., with an enzyme activity of 100,000.

[0031] Example 1

[0032] A method for preparing a compound water-retaining agent for food comprises the following steps:

[0033] (1) Add 5 g of papain, 3 g of transglutaminase, and 2 g of cellulase to 200 g of water to obtain an enzyme preparation aqueous solution;

[0034] (2) 750 g of sodium tripolyphosphate, 200 g of enzyme preparation aqueous solution, 50 g of sodium dihydrogen phosphate, 40 g of glycerol, 50 g of soybean oil microcapsules, 10 g of sodium carbonate, and 10 g of sodium citrate were added to 1000 g of water and stirred at room temperature for 0.5 hour; 50 g of maltodextrin, 20 g of soy protein isolate, 20 g of pea protein, 10 g of peanut protein, 20 g of xanthan gum, and 30 g of guar gum were added and stirred at 38° C. for 0.5 hour, cooled to room temperature, ground and passed through a 500 mesh sieve; finally, granulated by a centrifugal spray granulator and dried to obtain the compound water-retaining agent for food.

[0035] The preparation method of the soybean oil microcapsules is as follows:

[0036] 6 g of casein was added to 120 g of water and stirred at 90°C for 0.5 h. 30 g of glucomannan and 15 g of lactose were added and stirred for 0.5 h. The mixture was then stirred at 90°C for 4 h. The mixture was cooled to 50°C, 30 g of soybean oil was added, and the mixture was homogenized at 35 MPa for three times, each time for 5 min, to obtain an oil-in-water solution. The solution was then dried in a spray dryer at an inlet temperature of 185°C, an outlet temperature of 80°C, and a feed rate of 600 mL·h. -1 , and obtain the soybean oil microcapsules.

[0037] Example 2

[0038] A method for preparing a compound water-retaining agent for food comprises the following steps:

[0039] (1) Add 5 g of papain, 3 g of transglutaminase, and 2 g of cellulase to 200 g of water to obtain an enzyme preparation aqueous solution;

[0040] (2) 750 g of sodium tripolyphosphate, 200 g of enzyme preparation aqueous solution, 50 g of sodium dihydrogen phosphate, 40 g of glycerol, 50 g of algae oil microcapsules, 10 g of sodium carbonate, and 10 g of sodium citrate were added to 1000 g of water and stirred at room temperature for 0.5 hour; 50 g of maltodextrin, 20 g of soy protein isolate, 20 g of pea protein, 10 g of peanut protein, 20 g of xanthan gum, and 30 g of guar gum were added and stirred at 38° C. for 0.5 hour, cooled to room temperature, ground and passed through a 500 mesh sieve; finally, granulated by a centrifugal spray granulator and dried to obtain the compound water-retaining agent for food.

[0041] The preparation method of the algae oil microcapsules is as follows:

[0042] 6 g of casein was added to 120 g of water and stirred at 90 ° C for 0.5 hours. 30 g of glucomannan and 15 g of lactose were added and stirred for 0.5 hours. The mixture was stirred at 90 ° C for 4 hours. The mixture was cooled to 50 ° C, 30 g of algae oil was added, and the mixture was homogenized at 35 MPa for three times, each time for 5 minutes to obtain an oil-in-water solution. The mixture was dried in a spray dryer with an inlet air temperature of 185 ° C and an outlet air temperature of 80 ° C. The feed rate was 600 mL·h -1 , and obtain the algae oil microcapsules.

[0043] Example 3

[0044] A method for preparing a compound water-retaining agent for food comprises the following steps:

[0045] (1) Add 5 g of papain, 3 g of transglutaminase, and 2 g of cellulase to 200 g of water to obtain an enzyme preparation aqueous solution;

[0046] (2) 750 g of sodium tripolyphosphate, 200 g of enzyme preparation aqueous solution, 50 g of sodium dihydrogen phosphate, 40 g of glycerol, 50 g of sweet almond oil microcapsules, 10 g of sodium carbonate, and 10 g of sodium citrate were added to 1000 g of water and stirred at room temperature for 0.5 hour; 50 g of maltodextrin, 20 g of soy protein isolate, 20 g of pea protein, 10 g of peanut protein, 20 g of xanthan gum, and 30 g of guar gum were added and stirred at 38°C for 0.5 hour, cooled to room temperature, ground and passed through a 500 mesh sieve; finally, granulated by a centrifugal spray granulator and dried to obtain the compound water-retaining agent for food.

[0047] The preparation method of the sweet almond oil microcapsules is as follows:

[0048] 6 g of casein was added to 120 g of water and stirred at 90°C for 0.5 h. 30 g of glucomannan and 15 g of lactose were added and stirred for 0.5 h. Stirring was continued at 90°C for 4 h. The solution was cooled to 50°C and 30 g of sweet almond oil was added. The solution was homogenized at 35 MPa for 5 min each time to obtain an oil-in-water solution. The solution was then dried in a spray dryer at an inlet temperature of 185°C, an outlet temperature of 80°C, and a feed rate of 600 mL·h. -1 , and obtain the sweet almond oil microcapsules.

[0049] Example 4

[0050] A method for preparing a compound water-retaining agent for food comprises the following steps:

[0051] (1) Add 5 g of papain, 3 g of transglutaminase, and 2 g of cellulase to 200 g of water to obtain an enzyme preparation aqueous solution;

[0052] (2) 750 g of sodium tripolyphosphate, 200 g of enzyme preparation aqueous solution, 50 g of sodium dihydrogen phosphate, 40 g of glycerol, 50 g of conjugated linoleic acid microcapsules, 10 g of sodium carbonate, and 10 g of sodium citrate were added to 1000 g of water and stirred at room temperature for 0.5 hour; 50 g of maltodextrin, 20 g of soy protein isolate, 20 g of pea protein, 10 g of peanut protein, 20 g of xanthan gum, and 30 g of guar gum were added and stirred at 38° C. for 0.5 hour, cooled to room temperature, ground and passed through a 500 mesh sieve; finally, granulated by a centrifugal spray granulator and dried to obtain the compound water-retaining agent for food.

[0053] The preparation method of the conjugated linoleic acid microcapsules is as follows:

[0054] 6 g of casein was added to 120 g of water and stirred at 90°C for 0.5 h. 30 g of glucomannan and 15 g of lactose were added and stirred for 0.5 h. The mixture was then stirred at 90°C for 4 h. The mixture was cooled to 50°C and 30 g of conjugated linoleic acid was added. The mixture was homogenized at 35 MPa for three times, each time for 5 min, to obtain an oil-in-water solution. The mixture was then dried in a spray dryer at an inlet temperature of 185°C, an outlet temperature of 80°C, and a feed rate of 600 mL·h. -1 , and obtain the conjugated linoleic acid microcapsules.

[0055] Example 5

[0056] A method for preparing a compound water-retaining agent for food comprises the following steps:

[0057] (1) Add 5 g of papain, 3 g of transglutaminase, and 2 g of cellulase to 200 g of water to obtain an enzyme preparation aqueous solution;

[0058] (2) 750 g of sodium tripolyphosphate, 200 g of enzyme preparation aqueous solution, 50 g of sodium dihydrogen phosphate, 40 g of glycerol, 50 g of sweet almond oil-conjugated linoleic acid composite microcapsules, 10 g of sodium carbonate, and 10 g of sodium citrate were added to 1000 g of water and stirred at room temperature for 0.5 hour; 50 g of maltodextrin, 20 g of soy protein isolate, 20 g of pea protein, 10 g of peanut protein, 20 g of xanthan gum, and 30 g of guar gum were added and stirred at 38° C. for 0.5 hour, cooled to room temperature, ground and passed through a 500 mesh sieve; finally, granulated by a centrifugal spray granulator and dried to obtain the compound water-retaining agent for food.

[0059] The preparation method of the sweet almond oil-conjugated linoleic acid composite microcapsules is as follows:

[0060] 6 g of casein was added to 120 g of water and stirred at 90°C for 0.5 h. 30 g of glucomannan and 15 g of lactose were added and stirred for another 0.5 h. The mixture was then stirred at 90°C for 4 h. The mixture was cooled to 50°C, 28 g of sweet almond oil and 2 g of conjugated linoleic acid were added, and the mixture was homogenized at 35 MPa for three times, each time for 5 min, to obtain an oil-in-water solution. The solution was then dried in a spray dryer at an inlet air temperature of 185°C, an outlet air temperature of 80°C, and a feed rate of 600 mL·h. -1 , and obtain the sweet almond oil-conjugated linoleic acid composite microcapsules.

[0061] Example 6

[0062] A method for preparing a compound water-retaining agent for food comprises the following steps:

[0063] (1) Add 5 g of papain, 3 g of transglutaminase, and 2 g of cellulase to 200 g of water to obtain an enzyme preparation aqueous solution;

[0064] (2) 750 g of sodium tripolyphosphate, 200 g of enzyme preparation aqueous solution, 50 g of sodium dihydrogen phosphate, 40 g of glycerol, 50 g of soybean oil-conjugated linoleic acid composite microcapsules, 10 g of sodium carbonate, and 10 g of sodium citrate were added to 1000 g of water and stirred at room temperature for 0.5 hour; 50 g of maltodextrin, 20 g of soy protein isolate, 20 g of pea protein, 10 g of peanut protein, 20 g of xanthan gum, and 30 g of guar gum were added and stirred at 38°C for 0.5 hour, cooled to room temperature, ground and passed through a 500 mesh sieve; finally, granulated by a centrifugal spray granulator and dried to obtain the compound water-retaining agent for food.

[0065] The preparation method of the soybean oil-conjugated linoleic acid composite microcapsules is as follows:

[0066] 6 g of casein was added to 120 g of water and stirred at 90°C for 0.5 h. 30 g of glucomannan and 15 g of lactose were added and stirred for 0.5 h. The mixture was then stirred at 90°C for 4 h. The mixture was cooled to 50°C, 28 g of soybean oil and 2 g of conjugated linoleic acid were added, and the mixture was homogenized at 35 MPa for 5 min each time to obtain an oil-in-water solution. The solution was then dried in a spray dryer at an inlet temperature of 185°C, an outlet temperature of 80°C, and a feed rate of 600 mL·h. -1 , and obtain the soybean oil-conjugated linoleic acid composite microcapsules.

[0067] Comparative Example 1

[0068] A method for preparing a compound water-retaining agent for food comprises the following steps:

[0069] (1) Add 5 g of papain, 3 g of transglutaminase, and 2 g of cellulase to 200 g of water to obtain an enzyme preparation aqueous solution;

[0070] (2) 750 g of sodium tripolyphosphate, 200 g of enzyme preparation aqueous solution, 50 g of sodium dihydrogen phosphate, 40 g of glycerol, 50 g of sweet almond oil, 10 g of sodium carbonate, and 10 g of sodium citrate were added to 1000 g of water and stirred at room temperature for 0.5 hour; 50 g of maltodextrin, 20 g of soy protein isolate, 20 g of pea protein, 10 g of peanut protein, 20 g of xanthan gum, and 30 g of guar gum were added and stirred at 38° C. for 0.5 hour, cooled to room temperature, ground and passed through a 500 mesh sieve; finally, granulated by a centrifugal spray granulator and dried to obtain the compound water-retaining agent for food.

[0071] Comparative Example 2

[0072] A method for preparing a compound water-retaining agent for food comprises the following steps:

[0073] (1) Add 5 g of papain, 3 g of transglutaminase, and 2 g of cellulase to 200 g of water to obtain an enzyme preparation aqueous solution;

[0074] (2) 750 g of sodium tripolyphosphate, 200 g of enzyme preparation aqueous solution, 50 g of sodium dihydrogen phosphate, 40 g of glycerol, 50 g of glucomannan, 10 g of sodium carbonate, and 10 g of sodium citrate were added to 1000 g of water and stirred at room temperature for 0.5 hour; 50 g of maltodextrin, 20 g of soy protein isolate, 20 g of pea protein, 10 g of peanut protein, 20 g of xanthan gum, and 30 g of guar gum were added and stirred at 38° C. for 0.5 hour, cooled to room temperature, ground and passed through a 500 mesh sieve; finally, granulated by a centrifugal spray granulator and dried to obtain the compound water-retaining agent for food.

[0075] Comparative Example 3

[0076] A method for preparing a compound water-retaining agent for food comprises the following steps:

[0077] (1) Add 5 g of papain, 3 g of transglutaminase, and 2 g of cellulase to 200 g of water to obtain an enzyme preparation aqueous solution;

[0078] (2) 750 g of sodium tripolyphosphate, 200 g of enzyme preparation aqueous solution, 50 g of sodium dihydrogen phosphate, 40 g of glycerol, 25 g of glucomannan, 25 g of sweet almond oil, 10 g of sodium carbonate, and 10 g of sodium citrate were added to 1000 g of water and stirred at room temperature for 0.5 hour; 50 g of maltodextrin, 20 g of soy protein isolate, 20 g of pea protein, 10 g of peanut protein, 20 g of xanthan gum, and 30 g of guar gum were added and stirred at 38° C. for 0.5 hour, cooled to room temperature, ground and passed through a 500 mesh sieve; finally, granulated by a centrifugal spray granulator and dried to obtain the compound water-retaining agent for food.

[0079] Test Example 1

[0080] Water retention test

[0081] The food-grade compound humectants prepared by the methods of Examples 1-6 and Comparative Examples 1-3 were used as test samples. 0.1g of the compound humectant was added to 10g of fresh ground pork, stirred for 1 minute, and then placed in a 15mL centrifuge tube for freezing. The samples were quickly cooled to -20°C at a rate of 10°C / min for 2 hours. The ground pork samples were tested for moisture before and after freezing using a meat moisture meter, and the water retention rate was calculated: water retention rate = 1 - {(mass of pork sample before freezing - mass of pork sample after freezing)} / mass of pork sample before freezing × 100%. Five groups of samples were prepared for each of Examples 1-5 and Comparative Examples 1-3, and a group of fresh ground pork samples without the compound humectant was included as a control group. The test data were averaged.

[0082] Table 1

[0083] control group Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Comparative Example 2 Comparative Example 3 Water retention rate 73.8% 81.3% 83.8% 89.5% 78.6% 90.3% 79.8% 67.9% 68.4% 73.0%

[0084] Freezing may cause a reduction in the moisture content of the pork minced meat sample due to water sublimation, and long-term or improper freezing will destroy the cell structure, affect the taste and nutrition, and thus reduce the quality of the meat. The water retention rate of the blank control group of the compound moisture retaining agent is significantly lower than that of other embodiments and comparative examples. Examples 1-3 use a composite of glucomannan and lactose as microcapsule wall materials, casein as an emulsifier, and soybean oil, algae oil and sweet almond oil as core materials respectively; the microcapsule structure can effectively isolate the influence of the external environment on the oil, and the compound moisture retaining agent combines the dissociated phosphate ions with the calcium ions in the meat protein, opens the protein molecular structure and increases its hydrophilicity. Among them, the sweet almond oil in Example 3 is rich in unsaturated fatty acids, and the prepared microcapsules can be filled in the pores of the protein network, reducing the loss of water during storage. Soybean oil has a high content of saturated fatty acids, which makes oil droplets easily aggregate and has a weak filling effect on the protein network. The linear structure of saturated fatty acids results in high interfacial tension with the microcapsule wall material, resulting in a lower water retention rate than in Example 3. Although algae oil is rich in unsaturated fatty acids, the double bonds of unsaturated fatty acids are more susceptible to reaction with oxygen. During processing, slight oxidation may cause the integrity of the microcapsule structure to decrease, thereby affecting water retention efficiency. Example 4 uses conjugated linoleic acid as the core material for microcapsules. Although conjugated linoleic acid, as a functional fatty acid, has the ability to interfere with protein structure, it has poor thermal stability when used alone. The microcapsule structure is easily broken by high-temperature frying, resulting in uncontrolled release behavior. The structural regulation effect is lower than that of sweet almond oil, which has better stability. Examples 5 and 6, respectively, combined sweet almond oil and soybean oil with conjugated linoleic acid as the core materials for the microcapsules. After compounding, the water retention rates were higher than those of Examples 1-4, which used a single core material. The water retention rate in Example 5 was significantly improved, demonstrating that the composite core material structure of conjugated linoleic acid and sweet almond oil has a synergistic effect on improving water retention. However, the water retention rate in Example 6 did not show a significant improvement, indicating that not all oil-based core materials can achieve the technical effect of increased water retention when combined with conjugated linoleic acid. Comparative Examples 1-3 were not microencapsulated. Comparative Example 1 directly added sweet almond oil, which is easily oxidized in air and affects its nutritional value. However, the free oil easily interacts hydrophobically with meat protein, disrupting the protein's hydrophilic network structure. Comparative Example 2 directly added glucomannan. While the single polysaccharide component can exert a certain water retention effect through water absorption and swelling, it lacks the composite structure formed by the oil and wall material and cannot effectively synergize with phosphate. In Comparative Example 3, glucomannan and sweet almond oil were directly added, but the two could not form a stable embedding structure. The hydrophobic effect of the oil still interfered with the protein network, and the water retention rate was lower than that of Example 3.

[0085] Test Example 2

[0086] Hardness and elasticity testing of fried meat products

[0087] The compound water-retaining agent for food obtained by the preparation method of Examples 1-6 and Comparative Examples 1-3 was used as a test sample, 0.2 g of the compound water-retaining agent for food was added to 10 g of fresh pork and rolled for 15 seconds to form a ball; starch was added and rolled for 15 seconds to coat the surface with a layer of starch to obtain a meat fried food sample, which was placed in a -18°C freezer for 48 hours; the sample was taken out and added to an oil pan at an oil temperature of 150°C and kept for 45 seconds, then taken out and cooled to room temperature; the hardness and elasticity of the meat product sample were tested using a TA-XTPlus physical property tester and a P50 probe, and the average value was taken after 5 measurements. The average value of the test data is summarized as shown in Table 2.

[0088] Table 2

[0089] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Comparative Example 2 Comparative Example 3 Hardness / g 153 150 146 156 142 154 170 166 161 elasticity / % 57 59 63 55 66 56 51 52 55

[0090] Examples 1-5 respectively incorporate microcapsules containing different oils as core materials. When the meat samples are fried, the oil slowly released from the microcapsules can penetrate into the meat protein network, weakening the cross-linking strength between protein molecules. Combined with other components such as xanthan gum and guar gum, the oil reduces the hardness of the meat products while maintaining high elasticity and tenderness.

[0091] In Example 1, the soybean oil has a high content of saturated fatty acids, and the oil droplets are easy to aggregate in the microcapsules. The oil released during frying is unevenly distributed, making it difficult to evenly weaken the forces between protein molecules, and the effect of improving hardness or elasticity is weak. Although the algae oil in Example 2 is also rich in unsaturated fatty acids, the double bonds of long-chain polyunsaturated fatty acids are more likely to undergo slight oxidation under the high temperature of frying, resulting in partial damage to the microcapsule wall material, faster oil release rate, and slightly lower elasticity. In Example 3, the unsaturated fatty acids in sweet almond oil are mainly monounsaturated fatty acids, with a small number of double bonds and most of them located in the middle of the carbon chain, which is relatively stable. The oxidation sensitivity is lower than that of the polyunsaturated fatty acids in algae oil; the hydrogen bonds and hydrophobic interactions formed with the microcapsule wall material are stronger, the mechanical strength of the interfacial film is higher, and it can withstand the high temperature impact and oil expansion pressure of the frying process. The microcapsules can maintain a more complete structure and nutritional value during the processing process. Example 4 uses conjugated linoleic acid as the core material of the microcapsule. Conjugated linoleic acid has a conjugated double bond structure and can produce binding interference with the hydrophobic segment of meat protein under high temperature environment. In Examples 5 and 6, sweet almond oil, soybean oil, and conjugated linoleic acid are respectively compounded as the core material of the microcapsule. Compared with a single fat core, a good structural synergistic relationship is formed between the two oils, which has a significant texture optimization effect. The conjugated linoleic acid in Example 5 has a conjugated double bond structure, which can produce binding interference with the hydrophobic segment of meat protein under high temperature environment, interrupting the excessive aggregation between proteins. However, the oxidative stability of conjugated linoleic acid itself is poor, and direct use will affect the technical effect due to the easy rupture of microcapsules. After adding sweet almond oil for compounding, sweet almond oil has good thermal stability and penetration ability, which can evenly release and lubricate the protein network during frying. When used in combination, sweet almond oil plays the role of carrier protection and release rhythm buffering, avoiding early structural damage of conjugated linoleic acid due to oxidation, and ultimately showing better water retention, lower hardness and higher elasticity. In Example 6, soybean oil and conjugated linoleic acid were compounded. Although the ratio was the same, soybean oil had a high saturated fatty acid content, high viscosity, and poor diffusivity, which caused problems such as uneven release and interface rupture of the microcapsules during frying. The technical effect was lower than that of Example 5. This shows that conjugated linoleic acid can only achieve significant synergistic effects when compounded with sweet almond oil in a core material structure, but cannot achieve the corresponding technical effect difference when compounded with soybean oil.

[0092] In Comparative Examples 1-3, sweet almond oil, glucomannan, and a mixture of sweet almond oil and glucomannan were directly added, respectively. The free oil in Comparative Example 1 was easily combined with starch to form stearin during the tumbling and freezing process, which aggravated the shrinkage and hardening of the protein network during frying and destroyed the elastic structure. Comparative Example 2 lacked the lubricating effect of oil, and dense cross-linking was easily formed between protein molecules. In Comparative Example 3, glucomannan was directly mixed with sweet almond oil, but the oil was not effectively wrapped and was still partially combined with starch, resulting in agglomeration and uneven wrapping, which reduced the tissue bonding strength of the starch layer and the pork during frying, and caused local excessive hardening or reduced elasticity of the pork.

[0093] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A method for preparing a compound water-retaining agent for food, characterized in that: The invention prepares the preparation by adding 70-80 parts of sodium tripolyphosphate, 15-25 parts of enzyme preparation aqueous solution, 4-6 parts of sodium dihydrogen phosphate, 2-6 parts of glycerol, 4-6 parts of microcapsules, 0.5-1.5 parts of sodium carbonate and 0.5-1.5 parts of sodium citrate to 80-120 parts of water, stirring at room temperature for 0.5-1 hour; and adding 4-6 parts of maltodextrin, 4-6 parts of protein additive and 4-6 parts of thickener.

2. The method for preparing the composite water-retaining agent for food according to claim 1, wherein: The method comprises the following steps, in parts by weight: (1) Add 0.5-1.5 parts of enzyme preparation to 15-25 parts of water to obtain an enzyme preparation aqueous solution; (2) Add 70-80 parts of sodium tripolyphosphate, 15-25 parts of enzyme preparation aqueous solution, 4-6 parts of sodium dihydrogen phosphate, 2-6 parts of glycerol, 4-6 parts of microcapsules, 0.5-1.5 parts of sodium carbonate, and 0.5-1.5 parts of sodium citrate to 80-120 parts of water, and stir at room temperature for 0.5-1 hour; add 4-6 parts of maltodextrin, 4-6 parts of protein additive, and 4-6 parts of thickener, stir at 35-40°C for 0.5-1 hour, cool to room temperature, grind through a 400-600 mesh sieve; finally, granulate by a centrifugal spray granulator, and obtain the compound water-retaining agent for food after drying.

3. The method for preparing the composite water-retaining agent for food according to claim 1 or 2, wherein: The enzyme preparation is a compound of papain, transglutaminase and cellulase.

4. The method for preparing the composite water-retaining agent for food according to claim 1 or 2, wherein: The thickener is one or more of xanthan gum, guar gum, locust bean gum and carrageenan.

5. The method for preparing the composite water-retaining agent for food according to claim 1 or 2, wherein: The protein additive is one or more of soy protein isolate, pea protein, and peanut protein.

6. The method for preparing the composite water-retaining agent for food according to claim 1 or 2, wherein: The preparation method of the microcapsules is as follows, in parts by weight: 0.5-0.8 parts of casein are added to 10-15 parts of water and stirred at 85-95° C. for 0.5-1 hour, 2-4 parts of glucomannan and 1-2 parts of lactose are added and stirred for 0.5-1 hour, and then stirred at 85-95° C. for 3-5 hours; the solution is cooled to 45-55° C., 2-4 parts of oil core material are added and homogenized to obtain an oil-in-water solution; and the solution is dried in a spray dryer to obtain the microcapsules.

7. The method for preparing the composite water-retaining agent for food according to claim 1 or 2, wherein: The oil core material is one or more of soybean oil, algae oil, sweet almond oil, and conjugated linoleic acid.

8. A compound water-retaining agent for food, characterized in that: Prepared according to any one of claims 1 to 8.