High-temperature-resistant composite colloid for gel food as well as preparation method and application of high-temperature-resistant composite colloid

Abstract

The invention discloses a high-temperature-resistant composite colloid for gel food as well as a preparation method and application of the high-temperature-resistant composite colloid. The composite colloid comprises thermal reversible gel particles and a composite colloid enhanced network. The gel particles are prepared by compounding modified flaxseed gum and zein and then carrying out centrifugal spray drying, and have good thermal stability and reversible gel characteristics. The composite colloid enhanced network comprises a primary network formed by nanocellulose and sodium alginate, an interpenetrating network formed by chitosan and xyloglucan, and a reversible ion-phenol cross-linked network formed by calcium ions and heat-stable polyphenol. Through the synergistic effect of the triple network structure, the composite colloid is endowed with excellent high temperature resistance, structural stability and self-repairing capability. And the composite colloid can load active components, is fine and smooth in taste and good in water retention, is suitable for food systems such as functional jelly and the like, and has a wide application prospect.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of food processing, and particularly relates to a high-temperature-resistant composite colloid for gel food and a preparation method and application thereof. BACKGROUND

[0002] Gel foods such as jelly and pudding are widely welcomed due to their unique taste and diverse flavors. With the upgrading of consumption, the market has put forward higher requirements for such products. Not only are they required to have smooth taste and stable structure, but they are also expected to have functionality (such as rich in probiotics, vitamins, antioxidants, etc.) and meet the natural and healthy trend of clean labels. However, there are many technical challenges in developing such high-performance functional gel foods. First, traditional gel systems, such as systems mainly composed of pectin and xanthan gum, have poor heat resistance. During high-temperature sterilization or hot filling, the network structure is easily destroyed and dehydrated, resulting in product texture degradation, hardening of taste, water loss, and loss of flavor. Second, many functional active substances (such as probiotics, polyphenols, and fat-soluble nutrients) are sensitive to heat, oxygen, and pH, and are easily inactivated during processing and storage, making it difficult to effectively deliver them. In addition, directly mixing active ingredients or nutritional enhancers into the gel matrix often results in damaged product texture (such as the formation of rough particles), uneven ingredient distribution, or the initiation of undesirable chemical reactions, affecting product stability and sensory quality.

[0003] To solve the above problems, microencapsulation technology is often used in the prior art to protect active ingredients. However, conventional microcapsule wall materials (such as gelatin and certain polysaccharides) have insufficient heat resistance and will melt and rupture at high temperatures, failing to provide effective protection for the core material. On the other hand, although some studies have improved heat resistance by strengthening the gel network itself, such as using a single sodium alginate-calcium ion crosslinking system, the network is often brittle and the ion crosslinking points are easily broken under high heat or mechanical shear, resulting in insufficient stability. Simply increasing the colloid concentration or adding a chemical crosslinking agent can improve heat resistance, but it will also sacrifice the product's taste, resulting in a hard and inflexible gel that does not meet the requirements of clean labels.

[0004] Therefore, there is an urgent need in the art to develop a new type of colloid system that can withstand high-temperature processing conditions, maintain a smooth and delicate taste and stable structure, and effectively load and protect functional ingredients, providing a solution for developing the next generation of high-performance functional gel foods. SUMMARY

[0005] Technical problems to be solved: Fruit jelly faces various quality problems during production and use. For example, fruit jelly is completely stuck together before being unsealed, and even melts when the weather gets hot, resulting in being unable to eat. In addition, the taste of fruit jelly is easily affected by temperature fluctuations, and ordinary colloids are difficult to withstand high-temperature processing during fruit jelly preparation, resulting in poor product quality, or using some chemical reagents to improve, which does not meet the concept of healthy food that people pursue. The gel particles prepared by modifying flaxseed gum and compounding with corn alcohol-soluble protein have the characteristics of high temperature resistance, and the particles have reversibility. The present application adopts a multiple cross-linking network structure to improve its high temperature resistance, and uses the rigid support provided by the high temperature resistant nano cellulose skeleton, and the protein-polysaccharide further forms a covalent network, and the reversible cross-linking network formed by calcium ions and polyphenols, the three-layer network is cross-linked and overlapped, and a three-dimensional network structure is constructed, and the gel particles are loaded to form a high-temperature-resistant composite colloid for gel food.

[0006] Technical scheme: A preparation method of a high-temperature-resistant composite colloid for gel food, comprising the following steps: S1. Preparation of modified flaxseed gum: after adding water to the flaxseed gum, water bath stirring is performed, the pH is adjusted to obtain a flaxseed gum solution, sorbic acid, chitosan acetic acid solution and sodium sulfite solution are sequentially added, nitrogen is continuously introduced during the whole process, constant temperature water bath stirring is performed, after the reaction is completed, the product is poured into anhydrous ethanol for precipitation, vacuum filtration is performed, and vacuum drying is performed after washing to obtain the modified flaxseed gum; S2. Preparation of corn alcohol-soluble protein nanoparticles: after ultrasonic treatment, the corn alcohol-soluble protein ethanol solution is dropped into water, rotary evaporation is performed, and the pH is adjusted to obtain a corn alcohol-soluble protein nanoparticle solution; S3. Preparation of gel particles: the modified flaxseed gum and the corn alcohol-soluble protein nanoparticle solution are mixed, the pH is adjusted, and after reaction on a shaking bed, low-speed homogenization is performed, and spray drying is performed to obtain the gel particles; S4. Preparation of nano cellulose-sodium alginate mixed solution: after mechanical stirring, the nano cellulose suspension is ultrasonically treated, a sodium alginate aqueous solution is prepared, water bath stirring is performed, then the nano cellulose suspension and the sodium alginate solution are mixed, and water bath stirring is continuously performed to obtain the nano cellulose-sodium alginate mixed solution; S5. Preparation of chitosan-wooden glucosan composite solution: chitosan acetic acid solution and wooden glucosan solution are mixed, vortex stirring and ultrasonic treatment are performed; S6. Preparation of calcium citrate-gallic acid-anthocyanin mixed system: a mixed solution is prepared by using calcium citrate, gallic acid and anthocyanin, and water bath ultrasonic treatment is performed; S7. Preparation of composite colloid: the nano cellulose-sodium alginate mixed solution and the chitosan-wooden glucosan composite solution are mixed and stirred, then the gel particles and the calcium citrate-gallic acid-anthocyanin mixed system are added, ultrasonic treatment is performed, konjac powder is further added and stirred, carrageenan and locust bean gum are further added and stirred, and finally cold storage and standing are performed to obtain the composite colloid.

[0007] Further, the concentration of the flaxseed gum solution in step S1 is 5-10 wt.%, the pH is adjusted to 7; the content of acetic acid in the chitosan acetic acid solution is 1-2 wt.%, the content of chitosan is 1-2 wt.%; the concentration of the sodium sulfite solution is 0.1 mol / L; the volume ratio of the flaxseed gum solution, sorbic acid, chitosan acetic acid solution, and sodium sulfite solution is (20-25):(4-6):(5-10):1; the temperature of the water bath stirring is 50-60℃; the temperature of the constant temperature water bath is 60-70℃, the stirring speed of the constant temperature water bath is 300-400 rpm, and the reaction time is 3-4 h; the vacuum drying conditions are: temperature 55-65℃, vacuum degree -0.09 MPa.

[0008] Further, the content of the zein in the zein ethanol solution in step S2 is 15-25 wt.%, the ethanol concentration of the ethanol solution is 60-80 wt.%; the power density of the ultrasonic treatment is 200-250 W / cm², the ultrasonic treatment time is 20-40 min, and the ultrasonic treatment temperature is 4-5℃; the mass ratio of the zein ethanol solution to water is (6-8):5; the rotary evaporation temperature is 40-50℃; and the pH is adjusted to 4-5.

[0009] Further, in step S3, the mass ratio of the modified flaxseed gum to the zein nanoparticle solution is 1:(4-6); the pH is adjusted to 4-7; the reaction time on the shaking table is 20-30 min; the low-speed homogenization speed is 1000-2000 rpm, and the low-speed homogenization time is 5-10 min; the particle size of the gel microparticles controlled by homogenization and spray drying is less than 5 μm.

[0010] Further, in step S4, the nanocellulose is plant-derived or bacterial-derived bacterial nanocellulose BNC, and the concentration of the nanocellulose suspension is 3 wt%-10 wt%; the mechanical stirring speed is 500 rpm, and the mechanical stirring time is 20-30 min; the ultrasonic treatment power is 200-300 W, and the time is 10-15 min; the concentration of the sodium alginate solution is 3 wt%-10 wt%, the water bath temperature is 50-60℃, the stirring speed is 300-400 rpm, and the stirring time is 30-40 min; the mass ratio of the nanocellulose suspension to the sodium alginate solution is (5-10):1, and the continued water bath stirring time is 1.5-2 h.

[0011] Further, the concentration of the chitosan acetic acid solution in step S5 is 0.5-1 wt.%; the mass ratio of the chitosan acetic acid solution to the xyloglucan solution is 1:(1-2); the rotational speed of the vortex stirring is 500-600 rpm, and the vortex stirring time is 15-30 min; the ultrasonic treatment power is 500-600 W, and the ultrasonic treatment time is 20-30 min.

[0012] Further, the water bath ultrasonic power in step S6 is 300-700 W, the water bath ultrasonic time is 20-25 min, and the water bath ultrasonic temperature is 40-60 DEG C; the content of calcium citrate in the calcium citrate-gallic acid-anthocyanin mixed system is 1-2 wt.%, and the content of gallic acid and anthocyanin is 0.1-0.5 wt.%.

[0013] Further, the mass ratio of the nanocellulose-sodium alginate mixed solution, the chitosan-xyloglucan composite solution, the gel particles, the calcium citrate-gallic acid-anthocyanin mixed system and the konjac powder in step S7 is (10-15):(15-20):(1-3):(5-15):(30-50); the mass ratio of the konjac powder, the carrageenan and the locust bean gum is (3-5):(2-3):2; the ultrasonic treatment power is 500-700 W, and the ultrasonic treatment time is 20-30 min; the cold storage and standing temperature is 4-5 DEG C, and the cold storage and standing time is 4-8 h.

[0014] The above preparation method obtains a high-temperature-resistant composite gel for gel food.

[0015] The above high-temperature-resistant composite gel for gel food is applied to the preparation of jelly. Beneficial effects

[0016] The present application can significantly improve the thermal stability of the microparticles by adding high-temperature-resistant chitosan to modify the linseed gum, so that the microparticles can still maintain the structure integrity in a high-temperature environment, the physical properties of the microparticles can be improved by the Maillard reaction of the corn protein and the modified linseed gum, the mechanical strength and stability of the microparticles can be improved, the jelly can be resistant to temperature fluctuations (such as transportation and temporary temperature control failure), the risk of melting or deformation can be reduced, the corn protein has good film-forming property and thermal plasticity, the linseed gum not only has good gel-forming capacity, but also can form reversible gel (after being destroyed at high temperature, the gel can be formed again when the temperature decreases), the combination of the two can form a stable complex, and the structure stability and heat resistance of the microparticles can be enhanced.

[0017] The gel microparticles and the composite polysaccharide-protein network released / swelled by the gel microparticles can form a more tough and more elastic gel network in cooperation with a main colloid, and the gel network can improve the chewiness and shape retention of jelly, and reduce the problem of brittle cracking or easy breaking. After being embedded in the gel network, the gel microparticles can effectively lock water, and significantly reduce the phenomenon of water separation (dehydration shrinkage) during storage.

[0018] In the present application, the particle size of the gel microparticles is controlled at about 5 μm, which is much smaller than the particle threshold value (about 20-50 μm) that can be perceived by the oral cavity, so that the application in food can ensure smooth mouthfeel, and the microgel structure can bring more delicate and more full mouthfeel, and has a large specific surface area, which is beneficial to uniform dispersion and rapid hydration in the food matrix; the microparticle structure is very suitable for loading probiotics, vitamins, minerals, plant active ingredients (such as polyphenols, carotenoids), flavor substances or fat-soluble nutrients (such as vitamin D, EPA / DHA) during preparation, which provides an ideal carrier for developing functional jelly (such as probiotic jelly, high-calcium jelly, Omega-3-rich jelly, antioxidant jelly).

[0019] In the present application, a complex cross-linked network is constructed by various cross-linking methods (such as ionic cross-linking, covalent cross-linking, and physical cross-linking), so as to improve the mechanical properties and stability of the colloid, and the internal nanocellulose skeleton provides rigid support; the second network layer forms an interpenetrating network to further enhance the structural stability; and the outer layer is a reversible cross-linked network formed by calcium ions and polyphenols, which can endow the colloid with self-repairing ability.

[0020] The components such as gallic acid and anthocyanin introduced in the present application not only can enhance the stability of the colloid, but also can endow the colloid with specific functionality; for example, gallic acid can enhance the stability of anthocyanin, so as to improve the color stability of the product; in addition, the modification of chitosan and gallic acid can improve the antioxidant and antibacterial properties of the colloid, which is helpful to prolong the shelf life of food and reduce the addition of chemical preservatives.

[0021] The anthocyanin added in the present application can endow the colloid with different colors, and the color and flavor of the final product can be improved by adding different anthocyanins. The controllable formula makes the method have a wide application prospect in the food industry, and in addition, the raw materials used in the method are mainly natural substances, which meets the current consumer's pursuit of natural and healthy food. DETAILED DESCRIPTION

[0022] The present application will be further described below in conjunction with examples, and the following examples are an explanation of the present application, and the present application is not limited to the following examples: Example 1

[0023] A preparation method of a high-temperature-resistant composite colloid for gel food, comprising the following steps: S1. Preparation of modified flaxseed gum: After adding water to the flaxseed gum, stir in a 50°C water bath, adjust the pH to 7, and prepare a 5wt.% flaxseed gum solution. Put 20 parts of flaxseed gum into a flask, dissolve chitosan in 2wt.% acetic acid solution, and the content of chitosan is 2wt.%. Then add 4 parts of sorbic acid, 10 parts of chitosan acetic acid solution, and 1 part of 0.1 mol / L sodium sulfite solution into the flask in turn. Throughout the process, nitrogen is introduced. Stir at 400 rpm in a constant temperature water bath at 60°C for 3h. After the reaction is completed, the product is precipitated in anhydrous ethanol, vacuum filtered, washed, and dried at 60°C under vacuum at -0.09MPa to obtain the modified flaxseed gum; S2. Preparation of zein nanoparticles: Dissolve zein in 60wt.% ethanol solution, the content of zein is 15wt.%, 200 W / cm² ultrasonic treatment for 30min, the temperature is controlled at 4-5°C, then the zein ethanol solution is obtained. Then, the zein ethanol solution is dropped into water, and rotary evaporation is carried out at 45°C. Adjust the pH to 5 to obtain the zein nanoparticle solution; S3. Preparation of gel microparticles: Mix 10 parts of modified flaxseed gum with 40 parts of zein nanoparticle solution, adjust the pH to 6, and react on a shaker for 20min. Then, homogenize at 2000 rpm for 5min to obtain the gel microparticles; S4. Preparation of nanocellulose-sodium alginate mixed solution: After 20min mechanical stirring at 500 rpm, 5wt.% nanocellulose suspension is treated with 200 W ultrasound for 10min. 5wt.% sodium alginate aqueous solution is stirred at 300 rpm in a 50°C water bath for 30min. Then, mix 20 parts of nanocellulose suspension with 4 parts of sodium alginate solution, and continue to stir in a water bath for 2h to obtain the nanocellulose-sodium alginate mixed solution; S5. Preparation of chitosan-xyloglucan complex solution: The chitosan acetic acid solution in S1, the concentration of xyloglucan solution is 1wt.%, mix 10 parts of chitosan acetic acid solution with 20 parts of xyloglucan solution, and stir at 500 rpm for 15min and treat with 500W ultrasound for 20min; S6. Preparation of calcium citrate-gallic acid-anthocyanin mixed system: Prepare a mixed solution of calcium citrate, gallic acid, and anthocyanin, wherein the content of calcium citrate is 2wt.%, and the content of gallic acid and anthocyanin is 0.5wt.%. Ultrasonic treatment at 500W for 25min in a 40°C water bath; S7. Preparation of the composite gel: 15 parts of nanocellulose-sodium alginate mixed solution and 15 parts of chitosan-wood portulacae solution were mixed and stirred, then 1 part of gel microparticles and 10 parts of calcium citrate-gallic acid-anthocyanin mixed system were added, 500W ultrasonic treatment for 30min, 30 parts of konjac powder was added and stirred, then 20 parts of carrageenan and 20 parts of locust bean gum were added and stirred, finally 4℃ cold storage for 8h to obtain the composite gel. Example 2

[0024] A preparation method of a high-temperature-resistant composite gel for gel food, comprising the following steps: S1. Preparation of modified flaxseed gum: after adding water, the flaxseed gum was stirred in a water bath at 50℃, and the pH was adjusted to 7 to prepare a 5wt.% flaxseed gum solution. 20 parts of flaxseed gum was loaded into a flask, and 2wt.% acetic acid solution was used to dissolve chitosan with a content of 2wt.%. Then 4 parts of sorbic acid, 10 parts of chitosan acetic acid solution, and 1 part of 0.1mol / L sodium sulfite solution were sequentially added to the flask. Nitrogen was continuously introduced throughout the process. The reaction was carried out at 60℃ constant temperature water bath with 400 rpm stirring for 3h. After the reaction was completed, the product was precipitated in anhydrous ethanol, vacuum filtered, washed, and then dried at 60℃ under vacuum-0.09MPa to obtain the modified flaxseed gum; S2. Preparation of zein nanoparticles: zein was dissolved in 60wt.% ethanol solution with a content of 15wt.%. The solution was treated with 200 W / cm² ultrasonic wave for 30min at a temperature of 4-5℃ to obtain a zein ethanol solution. Then the zein ethanol solution was dropped into water and rotary evaporated at 45℃. The pH was adjusted to 5 to prepare the zein nanoparticle solution; S3. Preparation of gel microparticles: 10 parts of modified flaxseed gum was mixed with 40 parts of zein nanoparticle solution, the pH was adjusted to 6, and then the mixture was reacted on a shaker for 20min and homogenized at a low speed of 2000 rpm for 5min to obtain the gel microparticles which were then spray dried; S4. Preparation of nanocellulose-sodium alginate mixed solution: 5wt.% nanocellulose suspension was mechanically stirred at 500 rpm for 20min and then treated with 200 W ultrasonic wave for 10min. 5wt.% sodium alginate aqueous solution was stirred at 50℃ water bath with 300 rpm for 30min. Then 20 parts of nanocellulose suspension and 4 parts of sodium alginate solution were mixed and continuously stirred at water bath for 2h to obtain the nanocellulose-sodium alginate mixed solution; S5. Preparation of chitosan-wood portulacae complex solution: the chitosan acetic acid solution was the same as in S1, and the concentration of wood portulacae solution was 1wt.%. 10 parts of chitosan acetic acid solution and 20 parts of wood portulacae solution were mixed and stirred at 500 rpm for 15min and treated with 500W ultrasonic wave for 20min; S6. Preparation of calcium citrate-gallic acid-anthocyanin mixed system: calcium citrate, gallic acid and anthocyanin were prepared into a mixed solution, wherein the content of calcium citrate was 2wt.%, the content of gallic acid and anthocyanin was 0.5wt.%, and 40℃ water bath 500W ultrasonic treatment for 25min; S7. Preparation of composite gel: 15 parts of nanocellulose-sodium alginate mixed solution was mixed with 15 parts of chitosan-wooden glucuronoxylan complex solution, then 2 parts of gel particles and 10 parts of calcium citrate-gallic acid-anthocyanin mixed system were added, 500W ultrasonic treatment for 30min, 30 parts of konjac powder was added and stirred, then 20 parts of carrageenan and 20 parts of locust bean gum were added and stirred, finally 4℃ cold storage for 8h to obtain the composite gel. Example 3

[0025] A preparation method of a high-temperature-resistant composite gel for gel food, comprising the following steps: S1. Preparation of modified flaxseed gum: flaxseed gum was added with water, then stirred in a 50℃ water bath, and the pH was adjusted to 7 to prepare a 5wt.% flaxseed gum solution. 20 parts of flaxseed gum was loaded into a flask, chitosan was dissolved in a 2wt.% acetic acid solution, and the content of chitosan was 2wt.%. Then 4 parts of sorbic acid, 10 parts of chitosan acetic acid solution and 1 part of 0.1mol / L sodium sulfite solution were sequentially added into the flask, and nitrogen was continuously introduced during the whole process. The reaction was carried out in a 60℃ constant temperature water bath with stirring at 400 rpm for 3h. After the reaction was completed, the product was precipitated in anhydrous ethanol, vacuum filtered, washed and dried at 60℃ under vacuum-0.09MPa to obtain the modified flaxseed gum; S2. Preparation of zein nanoparticles: zein was dissolved in a 60wt.% ethanol solution, and the content of zein was 15wt.%. The solution was treated by 200 W / cm² ultrasonic wave for 30min with the temperature controlled at 4-5℃ to obtain a zein ethanol solution. Then the zein ethanol solution was dropped into water, and rotary evaporation was carried out at 45℃. The pH was adjusted to 5 to prepare a zein nanoparticle solution; S3. Preparation of gel particles: 10 parts of modified flaxseed gum was mixed with 40 parts of zein nanoparticle solution, the pH was adjusted to 6, and the mixture was reacted on a shaker for 20min, then homogenized at a low speed of 2000 rpm for 5min to obtain gel particles which were then spray dried; S4. Preparation of nanocellulose-sodium alginate mixed solution: 5wt.% nanocellulose suspension was mechanically stirred at 500 rpm for 20min, and then treated by 200 W ultrasonic wave for 10min. 5wt.% sodium alginate aqueous solution was stirred at 50℃ water bath for 30min at 300 rpm. Then 20 parts of nanocellulose suspension was mixed with 4 parts of sodium alginate solution, and the mixture was continuously stirred at water bath for 2h to obtain a nanocellulose-sodium alginate mixed solution; S5. Preparation of chitosan-xyloglucan complex solution: The concentration of xyloglucan solution was 1 wt.%, 10 parts of chitosan acetic acid solution was mixed with 20 parts of xyloglucan solution, 500 rpm vortex stirring for 15 min and 500 W ultrasonic treatment for 20 min; S6. Preparation of calcium citrate-gallic acid-anthocyanin mixed system: The content of calcium citrate was 2 wt.%, the content of gallic acid and anthocyanin was 0.5 wt.%, 40℃ water bath 500 W ultrasonic for 25 min; S7. Preparation of composite gel: 15 parts of nanocellulose-alginic acid sodium mixed solution was mixed with 15 parts of chitosan-xyloglucan complex solution, then 3 parts of gel particles and 10 parts of calcium citrate-gallic acid-anthocyanin mixed system were added, 500 W ultrasonic treatment for 30 min, 30 parts of konjac powder was added and continued to stir, then 20 parts of carrageenan and 20 parts of locust bean gum were added and continued to stir, finally 4℃ cold storage for 8h to obtain the composite gel. Example 4

[0026] A preparation method of a high-temperature-resistant composite gel for gel food, comprising the following steps: S1. Preparation of modified flaxseed gum: After adding water, the flaxseed gum was stirred in a water bath at 50℃, the pH was adjusted to 7, and a 5wt.% flaxseed gum solution was prepared, 20 parts of flaxseed gum was loaded into a flask, 2wt.% acetic acid solution was used to dissolve chitosan, the content of chitosan was 2wt.%, then 4 parts of sorbic acid, 10 parts of chitosan acetic acid solution and 1 part of 0.1mol / L sodium sulfite solution were added into the flask in turn, nitrogen was introduced throughout the process, 400 rpm stirring was carried out in a constant temperature water bath at 60℃ for 3h, after the reaction was completed, the product was precipitated in anhydrous ethanol, vacuum filtration was carried out, and after washing, the product was dried at 60℃ under vacuum-0.09MPa to obtain the modified flaxseed gum; S2. Preparation of zein nanoparticles: Zein was dissolved in 60wt.% ethanol solution, the content of zein was 15wt.%, 200 W / cm² ultrasonic treatment was carried out for 30 min, the temperature was controlled at 4-5℃, zein ethanol solution was obtained, then the zein ethanol solution was dropped into water, 45℃ rotary evaporation was carried out, the pH was adjusted to 5, and zein nanoparticle solution was prepared; S3. Preparation of gel particles: 10 parts of modified flaxseed gum was mixed with 40 parts of zein nanoparticle solution, the pH was adjusted to 6, 2000 rpm low speed homogenization was carried out for 5 min after reaction for 20 min on a shaker, and gel particles were obtained by spray drying; S4. Preparation of nanocellulose-sodium alginate mixture: 5wt.% nanocellulose suspension was mechanically stirred at 500 rpm for 20 min, then treated with 200 W ultrasound for 10 min, 5wt.% sodium alginate aqueous solution was stirred at 300 rpm for 30 min in a 50℃ water bath, then 20 parts of nanocellulose suspension was mixed with 4 parts of sodium alginate solution, and the water bath was stirred for 2 h to obtain the nanocellulose-sodium alginate mixture; S5. Preparation of chitosan-wooden glucosan composite solution: chitosan acetic acid solution as in S1, the concentration of wooden glucosan solution was 1wt.%, 10 parts of chitosan acetic acid solution was mixed with 20 parts of wooden glucosan solution, and stirred at 500 rpm for 15 min and treated with 500 W ultrasound for 20 min; S6. Preparation of calcium citrate-gallic acid-anthocyanin mixed system: calcium citrate, gallic acid and anthocyanin were prepared into a mixed solution, the content of calcium citrate was 2wt.%, the content of gallic acid and anthocyanin was 0.5wt.%, and the water bath was treated with 500 W ultrasound for 25 min at 40℃; S7. Preparation of composite colloid: 15 parts of nanocellulose-sodium alginate mixture was mixed with 15 parts of chitosan-wooden glucosan composite solution, then 2 parts of gel particles and 5 parts of calcium citrate-gallic acid-anthocyanin mixed system were added, treated with 500 W ultrasound for 30 min, 30 parts of konjac powder was added and stirred, then 20 parts of carrageenan and 20 parts of locust bean gum were added and stirred, finally the composite colloid was obtained by placing in a 4℃ refrigerator for 8 h. Example 5

[0027] A preparation method of a high-temperature resistant composite colloid for gel food, comprising the following steps: S1. Preparation of modified flaxseed gum: flaxseed gum was added with water and stirred in a 50℃ water bath, the pH was adjusted to 7 to prepare a 5wt.% flaxseed gum solution, 20 parts of flaxseed gum solution was placed in a flask, chitosan was dissolved with 2wt.% acetic acid solution, the content of chitosan was 2wt.%, then 4 parts of sorbic acid, 5 parts of chitosan acetic acid solution and 1 part of 0.1 mol / L sodium sulfite solution were sequentially added into the flask, nitrogen was introduced throughout the process, and the reaction was carried out at 60℃ constant temperature water bath with stirring at 400 rpm for 3 h, after the reaction was completed, the product was precipitated in anhydrous ethanol, vacuum filtration, washed and dried at 60℃ under vacuum-0.09 MPa to obtain modified flaxseed gum; S2. Preparation of zein nanoparticles: zein was dissolved with 60wt.% ethanol solution, the content of zein was 15wt.%, treated with 200 W / cm² ultrasound for 30 min, the temperature was controlled at 4-5℃, zein ethanol solution was obtained, then the zein ethanol solution was dropped into water, rotary evaporation was carried out at 45℃, the pH was adjusted to 5, and zein nanoparticle solution was prepared; S3. Preparation of gel microparticles: 10 parts of modified flaxseed gum were mixed with 40 parts of zein nanoparticle solution, the pH was adjusted to 6, and then the mixture was homogenized at 2000 rpm for 5 min after reaction for 20 min on a shaker, and spray dried to obtain gel microparticles; S4. Preparation of nanocellulose-sodium alginate mixed solution: 5 wt.% nanocellulose suspension was mechanically stirred at 500 rpm for 20 min, and then ultrasonically treated at 200 W for 10 min. 5 wt.% sodium alginate aqueous solution was stirred at 300 rpm in a water bath at 50°C for 30 min. Then 20 parts of nanocellulose suspension and 4 parts of sodium alginate solution were mixed and stirred in a water bath for 2 h to obtain a nanocellulose-sodium alginate mixed solution; S5. Preparation of chitosan-wooden glucosan composite solution: The chitosan acetic acid solution was the same as in S1, and the concentration of the wooden glucosan solution was 1 wt.%. 10 parts of chitosan acetic acid solution and 20 parts of wooden glucosan solution were mixed and stirred at 500 rpm for 15 min and ultrasonically treated at 500 W for 20 min. S6. Preparation of calcium citrate-gallic acid-anthocyanin mixed system: A mixed solution was prepared from calcium citrate, gallic acid, and anthocyanin, wherein the content of calcium citrate was 2 wt.%, and the content of gallic acid and anthocyanin was 0.5 wt.%. The solution was ultrasonically treated at 500 W for 25 min in a water bath at 40°C. S7. Preparation of composite colloid: 15 parts of nanocellulose-sodium alginate mixed solution and 15 parts of chitosan-wooden glucosan composite solution were mixed and stirred, then 2 parts of gel microparticles and 10 parts of calcium citrate-gallic acid-anthocyanin mixed system were added, and ultrasonically treated at 500 W for 30 min. 30 parts of konjac powder were added and stirred again. Then 20 parts of carrageenan and 20 parts of locust bean gum were added and stirred again. Finally, the composite colloid was obtained by placing it in a refrigerator at 4°C for 8 h. Example 6

[0028] A method for preparing a high-temperature-resistant composite colloid for gel food, comprising the following steps: S1. Preparation of modified flaxseed gum: Flaxseed gum was added to water and stirred in a water bath at 50°C. The pH was adjusted to 7, and a 5 wt.% flaxseed gum solution was prepared. 20 parts of flaxseed gum were placed in a flask, and 2 wt.% chitosan acetic acid solution was prepared. The content of chitosan was 2 wt.%. Then 4 parts of sorbic acid, 10 parts of chitosan acetic acid solution, and 1 part of 0.1 mol / L sodium sulfite solution were added to the flask in sequence. Nitrogen was introduced throughout the process. The reaction was carried out in a constant-temperature water bath at 60°C and stirred at 400 rpm for 3 h. After the reaction was completed, the product was precipitated in anhydrous ethanol, vacuum filtered, washed, and dried at 60°C under vacuum at -0.09 MPa to obtain modified flaxseed gum. S2. Preparation of Zein Nanoparticles: Zein was dissolved in 60 wt.% ethanol solution, the content of zein was 15 wt.%, 200 W / cm2ultrasonic treatment for 30 min, the temperature was controlled at 4-5℃, then the zein ethanol solution was obtained, then the zein ethanol solution was dropped into water, rotary evaporation at 45℃, the pH was adjusted to 5, and the zein nanoparticle solution was prepared; S3. Preparation of Gel Microparticles: 10 parts of modified flaxseed gum was mixed with 60 parts of zein nanoparticle solution, the pH was adjusted to 6, and then it was placed on a shaker for 20 min, followed by low-speed homogenization at 2000 rpm for 5 min, and then spray drying to obtain gel microparticles; S4. Preparation of Nanocellulose-Sodium Alginate Mixture: 5 wt.% nanocellulose suspension was mechanically stirred at 500 rpm for 20 min, and then ultrasonically treated at 200 W for 10 min, 5 wt.% sodium alginate aqueous solution was stirred at 300 rpm in a water bath at 50℃ for 30 min, then 20 parts of nanocellulose suspension was mixed with 4 parts of sodium alginate solution, and the mixture was further stirred in a water bath for 2 h to obtain a nanocellulose-sodium alginate mixture; S5. Preparation of Chitosan-Xyloglucan Composite Solution: The chitosan acetic acid solution in S1 and the xyloglucan solution with a concentration of 1 wt.% were mixed, 10 parts of chitosan acetic acid solution was mixed with 20 parts of xyloglucan solution, and then it was stirred at 500 rpm for 15 min and ultrasonically treated at 500 W for 20 min; S6. Preparation of Calcium Citrate-Gallic Acid- Anthocyanin Mixture: Calcium citrate, gallic acid and anthocyanin were prepared into a mixture, the content of calcium citrate was 2 wt.%, and the content of gallic acid and anthocyanin was 0.5 wt.%, and then it was ultrasonically treated at 500 W for 25 min in a water bath at 40℃; S7. Preparation of Composite Colloid: 15 parts of nanocellulose-sodium alginate mixture was mixed with 15 parts of chitosan-xyloglucan composite solution, then 2 parts of gel microparticles and 10 parts of calcium citrate-gallic acid-anthocyanin mixture were added, and then it was ultrasonically treated at 500 W for 30 min, 30 parts of konjac powder was added and stirred, then 20 parts of carrageenan and 20 parts of locust bean gum were added and stirred, and finally it was stored at 4℃ for 8 h to obtain a composite colloid. Comparative Example 1

[0029] The difference between this comparative example and Example 2 is that no gel microparticles are added, and the specific process is as follows: S1. Preparation of nanocellulose-sodium alginate mixed solution: 5wt.% nanocellulose suspension was mechanically stirred at 500 rpm for 20 min, then treated with 200 W ultrasonic for 10 min, 5wt.% sodium alginate aqueous solution was stirred at 300 rpm for 30 min in a 50℃ water bath, then 20 parts of nanocellulose suspension was mixed with 4 parts of sodium alginate solution, and the water bath was continued to stir for 2h to obtain the nanocellulose-sodium alginate mixed solution; S2. Preparation of chitosan-wooden glucosan composite solution: chitosan acetic acid solution was the same as in S1, the concentration of wooden glucosan solution was 1wt.%, 10 parts of chitosan acetic acid solution was mixed with 20 parts of wooden glucosan solution, and was stirred at 500 rpm for 15 min and treated with 500 W ultrasonic for 20 min; S3. Preparation of calcium citrate-gallic acid-anthocyanin mixed system: calcium citrate, gallic acid and anthocyanin were prepared into a mixed solution, the content of calcium citrate was 2wt.%, the content of gallic acid and anthocyanin was 0.5wt.%, and the water bath was treated with 500 W ultrasonic for 25 min at 40℃; S4. Preparation of composite colloid: 15 parts of nanocellulose-sodium alginate mixed solution was mixed with 15 parts of chitosan-wooden glucosan composite solution, then 10 parts of calcium citrate-gallic acid-anthocyanin mixed system was added, treated with 500 W ultrasonic for 30 min, 30 parts of konjac powder was added and stirred, then 20 parts of carrageenan and 20 parts of locust bean gum were added and stirred, finally the composite colloid was obtained by placing in a 4℃ refrigerator for 8h. Comparative Example 2

[0030] The difference between this comparative example and Example 2 is that the flaxseed gum is not modified, and the specific process is as follows: S1. Preparation of corn alcohol-soluble protein nanoparticles: corn alcohol-soluble protein was dissolved in 60wt.% ethanol solution, the content of corn alcohol-soluble protein was 15wt.%, and the corn alcohol-soluble protein ethanol solution was obtained by treating with 200 W / cm² ultrasonic for 30 min at a temperature of 4-5℃, then the corn alcohol-soluble protein ethanol solution was dropped into water, and the pH was adjusted to 5 by rotary evaporation at 45℃ to obtain the corn alcohol-soluble protein nanoparticle solution; S2. Preparation of gel microparticles: 10 parts of flaxseed gum was mixed with 40 parts of corn alcohol-soluble protein nanoparticle solution, the pH was adjusted to 6, and the mixture was reacted on a shaker for 20 min, then homogenized at 2000 rpm for 5 min to obtain the gel microparticles; S3. Preparation of nanocellulose-sodium alginate mixture: 5wt.% nanocellulose suspension was mechanically stirred at 500 rpm for 20 min, then ultrasonically treated at 200 W for 10 min, 5wt.% sodium alginate aqueous solution was stirred at 300 rpm for 30 min in a 50℃ water bath, then 20 parts of nanocellulose suspension was mixed with 4 parts of sodium alginate solution, and the water bath was continuously stirred for 2 h to obtain the nanocellulose-sodium alginate mixture; S4. Preparation of chitosan-wooden glucosan composite solution: chitosan acetic acid solution was prepared as in S1, the concentration of wooden glucosan solution was 1wt.%, 10 parts of chitosan acetic acid solution was mixed with 20 parts of wooden glucosan solution, and was stirred at 500 rpm for 15 min and ultrasonically treated at 500 W for 20 min; S5. Preparation of calcium citrate-gallic acid-anthocyanin mixed system: calcium citrate, gallic acid and anthocyanin were prepared into a mixed solution, the content of calcium citrate was 2wt.%, the content of gallic acid and anthocyanin was 0.5wt.%, and the ultrasonic treatment was carried out at 500 W for 25 min in a 40℃ water bath; S6. Preparation of composite colloid: 15 parts of nanocellulose-sodium alginate mixture was mixed with 15 parts of chitosan-wooden glucosan composite solution, then 2 parts of gel particles and 10 parts of calcium citrate-gallic acid-anthocyanin mixed system were added, and the ultrasonic treatment was carried out at 500 W for 30 min, 30 parts of konjac powder was continuously stirred, then 20 parts of carrageenan and 20 parts of locust bean gum were continuously stirred, and finally the composite colloid was obtained by cold storage at 4℃ for 8 h. Comparative Example 3

[0031] The difference between this comparative example and Example 2 is that no nanocellulose-sodium alginate mixture is added, and the specific process is as follows: S1. Preparation of modified flaxseed gum: flaxseed gum was added with water, and stirred in a 50℃ water bath, the pH was adjusted to 7, and a 5wt.% flaxseed gum solution was prepared, 20 parts of flaxseed gum was loaded into a flask, chitosan was dissolved in 2wt.% acetic acid solution, the content of chitosan was 2wt.%, then 4 parts of sorbic acid, 10 parts of chitosan acetic acid solution and 1 part of 0.1 mol / L sodium sulfite solution were sequentially added into the flask, nitrogen was continuously introduced during the whole process, and the reaction was carried out at 60℃ constant temperature water bath with stirring at 400 rpm for 3 h, after the reaction was completed, the product was precipitated in anhydrous ethanol, vacuum filtration, washed and dried at 60℃ under vacuum-0.09 MPa to obtain the modified flaxseed gum; S2. Preparation of zein nanoparticles: zein was dissolved in 60wt.% ethanol solution, the content of zein was 15wt.%, and the ultrasonic treatment was carried out at 200 W / cm² for 30 min, the temperature was controlled at 4-5℃, then the zein ethanol solution was dropped into water, and rotary evaporation was carried out at 45℃, the pH was adjusted to 5, and the zein nanoparticle solution was prepared. S3. Preparation of gel microparticles: 10 parts of modified flaxseed gum were mixed with 40 parts of zein nanoparticle solution, the pH was adjusted to 6, and then the mixture was reacted on a shaker for 20 min and homogenized at a low speed of 2000 rpm for 5 min. The gel microparticles were obtained by spray drying; S4. Preparation of chitosan-wooden glucosan complex solution: The chitosan-acetic acid solution in S1 and the wooden glucosan solution with a concentration of 1 wt.% were mixed, 10 parts of the chitosan-acetic acid solution and 20 parts of the wooden glucosan solution were mixed, and then the mixture was stirred at a vortex of 500 rpm for 15 min and treated with ultrasound at 500 W for 20 min; S5. Preparation of calcium citrate-gallic acid-anthocyanin mixed system: The calcium citrate-gallic acid-anthocyanin mixed solution was prepared, wherein the content of calcium citrate was 2 wt.%, and the content of gallic acid and anthocyanin was 0.5 wt.%; the mixed solution was treated with ultrasound at 500 W for 25 min in a water bath at 40°C; S6. Preparation of complex colloid: 15 parts of the chitosan-wooden glucosan complex solution, 2 parts of the gel microparticles, and 10 parts of the calcium citrate-gallic acid-anthocyanin mixed system were added, and the mixture was treated with ultrasound at 500 W for 30 min. Then, 30 parts of konjac powder were added and stirred, 20 parts of carrageenan and 20 parts of locust bean gum were added and stirred, and finally the complex colloid was obtained by storing at 4°C for 8 h. Comparative Example 4

[0032] The difference between this comparative example and Example 2 is that no chitosan-wooden glucosan complex solution is added, and the preparation process is as follows: S1. Preparation of modified flaxseed gum: The flaxseed gum was dissolved in water, and then the mixture was stirred in a water bath at 50°C. The pH was adjusted to 7, and a 5 wt.% flaxseed gum solution was prepared. Then, 20 parts of the flaxseed gum solution were added into a flask, and 2 wt.% acetic acid solution was used to dissolve chitosan, and the content of chitosan was 2 wt.%. Then, 4 parts of sorbic acid, 10 parts of the chitosan-acetic acid solution, and 1 part of 0.1 mol / L sodium sulfite solution were sequentially added into the flask. Nitrogen was introduced throughout the process, and the mixture was stirred at 400 rpm in a constant-temperature water bath at 60°C for 3 h. After the reaction, the product was precipitated in anhydrous ethanol, vacuum-filtered, washed, and then dried at 60°C under vacuum at -0.09 MPa to obtain the modified flaxseed gum. S2. Preparation of zein nanoparticle solution: Zein was dissolved in 60 wt.% ethanol solution, and the content of zein was 15 wt.%. The mixture was treated with ultrasound at 200 W / cm² for 30 min, and the temperature was controlled at 4-5°C to obtain a zein ethanol solution. Then, the zein ethanol solution was added dropwise into water, and rotary evaporation was performed at 45°C. The pH was adjusted to 5 to obtain the zein nanoparticle solution. S3. Preparation of gel microparticles: 10 parts of modified flaxseed gum were mixed with 40 parts of zein nanoparticle solution, the pH was adjusted to 6, and then the mixture was reacted on a shaker for 20 min and homogenized at 2000 rpm for 5 min. The gel microparticles were obtained by spray drying; S4. Preparation of nanocellulose-sodium alginate mixture: 5 wt.% nanocellulose suspension was mechanically stirred at 500 rpm for 20 min, then treated with 200 W ultrasound for 10 min. 5 wt.% sodium alginate aqueous solution was stirred at 300 rpm in a 50°C water bath for 30 min. Then 20 parts of nanocellulose suspension and 4 parts of sodium alginate solution were mixed and stirred in a water bath for 2 h to obtain the nanocellulose-sodium alginate mixture; S5. Preparation of calcium citrate-gallic acid-anthocyanin mixed system: calcium citrate, gallic acid, and anthocyanin were prepared into a mixed solution, wherein the content of calcium citrate was 2 wt.%, and the content of gallic acid and anthocyanin was 0.5 wt.%. The mixed solution was treated with 500 W ultrasound in a 40°C water bath for 25 min; S6. Preparation of composite colloid: 15 parts of nanocellulose-sodium alginate mixture were added to 2 parts of gel microparticles and 10 parts of calcium citrate-gallic acid-anthocyanin mixed system, and treated with 500 W ultrasound for 30 min. Then 30 parts of konjac powder were added and stirred again. Then 20 parts of carrageenan and 20 parts of locust bean gum were added and stirred. Finally, the composite colloid was obtained by placing it in a 4°C refrigerator for 8 h. Comparative Example 5

[0033] The difference between this comparative example and Example 2 is that no calcium citrate-gallic acid-anthocyanin mixed system is added, and the specific process is as follows: S1. Preparation of modified flaxseed gum: Flaxseed gum was dissolved in water and stirred in a 50°C water bath. The pH was adjusted to 7, and a 5 wt.% flaxseed gum solution was prepared. 20 parts of flaxseed gum were placed in a flask, and 2 wt.% acetic acid solution was used to dissolve chitosan, with a chitosan content of 2 wt.%. Then 4 parts of sorbic acid, 10 parts of chitosan acetic acid solution, and 1 part of 0.1 mol / L sodium sulfite solution were added to the flask in sequence. Nitrogen was introduced throughout the process, and the reaction was carried out at 60°C in a constant-temperature water bath with stirring at 400 rpm for 3 h. After the reaction was completed, the product was precipitated in anhydrous ethanol, vacuum filtered, washed, and then dried at 60°C under vacuum at -0.09 MPa to obtain the modified flaxseed gum; S2. Preparation of zein nanoparticle solution: Zein was dissolved in 60 wt.% ethanol solution, and the zein content was 15 wt.%. The solution was treated with 200 W / cm² ultrasound for 30 min, with the temperature controlled at 4-5°C. Then the zein ethanol solution was added dropwise into water, and rotary evaporation was carried out at 45°C. The pH was adjusted to 5 to obtain the zein nanoparticle solution; S3. Preparation of gel microparticles: 10 parts of modified flaxseed gum were mixed with 40 parts of zein nanoparticle solution, the pH was adjusted to 6, and then the mixture was reacted on a shaker for 20 min and homogenized at a low speed of 2000 rpm for 5 min. The gel microparticles were obtained by spray drying. S4. Preparation of nanocellulose-sodium alginate mixed solution: 5 wt.% of nanocellulose suspension was mechanically stirred at 500 rpm for 20 min, and then treated with ultrasonic waves at 200 W for 10 min. 5 wt.% of sodium alginate aqueous solution was stirred at 300 rpm in a water bath at 50 °C for 30 min. Then, 20 parts of nanocellulose suspension and 4 parts of sodium alginate solution were mixed and stirred in a water bath for 2 h to obtain the nanocellulose-sodium alginate mixed solution. S5. Preparation of chitosan-wooden glucosan composite solution: The chitosan acetic acid solution was the same as in S1, and the concentration of the wooden glucosan solution was 1 wt.%. 10 parts of chitosan acetic acid solution and 20 parts of wooden glucosan solution were mixed and stirred at 500 rpm for 15 min and treated with ultrasonic waves at 500 W for 20 min. S6. Preparation of composite colloid: 15 parts of nanocellulose-sodium alginate mixed solution and 15 parts of chitosan-wooden glucosan composite solution were mixed and stirred, then 2 parts of gel microparticles were added and treated with ultrasonic waves at 500 W for 30 min, 30 parts of konjac powder were added and stirred, 20 parts of carrageenan and 20 parts of locust bean gum were added and stirred, and finally the composite colloid was obtained by storing at 4 °C for 8 h. Comparative Example 6

[0034] The difference between this comparative example and Example 3 is that no zein nanoparticles are prepared, and the specific process is as follows: S1. Preparation of modified flaxseed gum: After adding water, the flaxseed gum was stirred in a water bath at 50 °C, and the pH was adjusted to 7 to prepare a 5 wt.% flaxseed gum solution. 20 parts of flaxseed gum were loaded into a flask, and 2 wt.% of chitosan acetic acid solution was added to dissolve chitosan, and the content of chitosan was 2 wt.%. Then, 4 parts of sorbic acid, 10 parts of chitosan acetic acid solution, and 1 part of 0.1 mol / L sodium sulfite solution were sequentially added to the flask, and nitrogen was continuously introduced during the whole process. The reaction was carried out at 60 °C in a constant temperature water bath with stirring at 400 rpm for 3 h. After the reaction was completed, the product was precipitated in anhydrous ethanol, vacuum filtered, washed, and then dried at 60 °C under vacuum at -0.09 MPa to obtain the modified flaxseed gum. S2. Preparation of zein solution: 1.5 g of zein was dissolved in 100 mL of water, and the solution was treated with ultrasonic waves at 200 W / cm² for 30 min to obtain the zein solution. S3. Preparation of gel microparticles: 10 parts of modified flaxseed gum were mixed with 40 parts of zein solution, the pH was adjusted to 6, and then the mixture was reacted on a shaker for 20 min and homogenized at a low speed of 2000 rpm for 5 min. The gel microparticles were obtained by spray drying. S4. Preparation of nanocellulose-sodium alginate mixed solution: 5wt.% nanocellulose suspension was mechanically stirred at 500 rpm for 20 min, then ultrasonically treated at 200 W for 10 min, 5wt.% sodium alginate aqueous solution was stirred at 300 rpm for 30 min in a 50℃ water bath, then 20 parts of nanocellulose suspension was mixed with 4 parts of sodium alginate solution, and the water bath stirring was continued for 2 h to obtain the nanocellulose-sodium alginate mixed solution; S5. Preparation of chitosan-wooden glucosan composite solution: chitosan acetic acid solution was prepared as in S1, the concentration of wooden glucosan solution was 1wt.%, 10 parts of chitosan acetic acid solution was mixed with 20 parts of wooden glucosan solution, and vortex stirring was carried out at 500 rpm for 15 min and ultrasonic treatment was carried out at 500 W for 20 min; S6. Preparation of calcium citrate-gallic acid-anthocyanin mixed system: calcium citrate, gallic acid and anthocyanin were prepared into a mixed solution, the content of calcium citrate was 2wt.%, the content of gallic acid and anthocyanin was 0.5wt.%, and ultrasonic treatment was carried out at 500 W for 25 min in a 40℃ water bath; S7. Preparation of composite colloid: 15 parts of nanocellulose-sodium alginate mixed solution was mixed with 15 parts of chitosan-wooden glucosan composite solution, then 2 parts of gel particles and 10 parts of calcium citrate-gallic acid-anthocyanin mixed system were added, ultrasonic treatment was carried out at 500 W for 30 min, 30 parts of konjac powder was added for continuous stirring, then 20 parts of carrageenan and 20 parts of locust bean gum were added for continuous stirring, and finally 4℃ cold storage and standing for 8 h obtained the composite colloid. Index test

[0035] Textural properties-thermal stability TA-XT plus texture analyzer was used, p / 36 probe was selected to analyze the hardness (g) and elasticity of emulsion gels with different oil phase concentrations, the test speed was 1.0 mm / s, and the trigger force was 5.0 g. The samples before and after heating at 65℃ for 5 min were detected by this method to investigate the influence of heating on the texture of the composite colloid.

[0036] The results are shown in Table 1, the hardness and elasticity of the composite colloid in the examples are higher than those in the comparative examples. Gel particles have the greatest influence on hardness and thermal stability. The change rate of hardness and elasticity after heating is the largest in Comparative Example 1 which lacks gel particles. The decrease of hardness and elasticity in Comparative Examples 3-5 and the change of elasticity after heating more than 50% indicate that multiple cross-linking networks can effectively stabilize the colloid and are indispensable. And the elasticity of the examples before heating is all higher than 75%, which will give better mouthfeel when applied to jelly, and the elasticity after heating is still greater than 60%.

[0037] Table 1 Textural properties of composite colloid Water retention Take 5.0 g of the colloidal sample and place it in a centrifuge tube. Centrifuge at 3000 rpm for 5 min, then place the centrifuge tube in a 100℃ water bath for 40 min, and immediately cool it to 4℃ in a cold water bath. Pour the liquid discharged from the centrifuge tube into a pre-weighed dry empty bottle, dry in an oven at 105℃ for 24 h, then cool in a desiccator and weigh to determine the water exudation, expressed as a percentage of the sample weight. The following formula is used to calculate: where m 前 is the mass of the colloidal before heating, and m 后 is the mass of the colloidal after heating.

[0038] As shown in Table 2, the water retention of the comparative examples is all less than 75%, and the water holding capacity is poor. Increasing the amount of gel particles (Examples 1-3) will increase the water retention, but the increase is decreasing. The reduction of the calcium citrate-gallic acid-anthocyanin mixed system (Example 4 and Comparative Example 5) will reduce the water retention. The absence of key ingredients, nanocellulose-sodium alginate mixed solution (Comparative Example 3) and chitosan-wooden glucan complex solution (Comparative Example 4), will significantly reduce the water retention.

[0039] Table 2 Water retention of composite colloids Sensory evaluation Jelly preparation: The composite colloids prepared in Examples 1-6 and Comparative Examples 1-6 were soaked in water, and heated sugar water was added with continuous stirring. When cooled to about 50-60℃, concentrated fruit juice and lemon juice were added. Then filtered, filled into molds, and refrigerated overnight.

[0040] This program invites 10 university students to form a sensory evaluation team to evaluate the appearance, taste, and smell of the jellies prepared in Examples 1-6 and Comparative Examples 1-6, and calculate the comprehensive score according to a certain proportion. The sensory evaluation is scored according to the evaluation criteria, and the average value is taken.

[0041] The results are shown in Table 3. The addition of gel particles mainly affects the appearance and taste, and the taste and appearance scores of Comparative Example 1 decrease significantly. The calcium citrate-gallic acid-anthocyanin mixed system may affect the color and smell, resulting in a decrease in the appearance, taste, and smell scores of Comparative Example 5. The absence or unmodified key ingredients in Comparative Examples 1-6 results in a significant decrease in the appearance, taste, and smell scores, especially the absence of nanocellulose-sodium alginate mixed solution in Comparative Example 3, which has the lowest score.

[0042] Table 3 Sensory evaluation score table of jelly Stability evaluation The prepared jelly was placed in a 40℃ water bath for 1 week, and then sensory evaluation was performed again.

[0043] The embodiment 3 with the highest sensory evaluation score was selected for evaluation. The results are shown in Table 4. The embodiment 3 has stable ingredients such as gel particles, nanocellulose-sodium alginate mixed solution, chitosan-wooden glucosan complex solution, calcium citrate-gallic acid-anthocyanin mixed system, and has a smaller score decrease after high temperature, with a comprehensive difference of -3. The control example lacks key ingredients such as gel particles, modified flaxseed gum, and nanoparticles, and has a larger score decrease after high temperature, with a comprehensive difference of -10 to -15. The control example 3 lacks nanocellulose-sodium alginate mixed solution and has the worst stability, with a comprehensive difference of -15.

[0044] Table 4 Sensory evaluation score table of jelly

[0045] The above description is only the preferred embodiment of the present application, and does not limit the present application in any form. Any person skilled in the art can make many possible changes and modifications to the technical solutions of the present application, or modify equivalent embodiments, without departing from the spirit and technical solutions of the present application, by using the disclosed methods and technical contents. Therefore, any simple modification, equivalent replacement, equivalent change and modification of the above embodiments made in accordance with the technical essence of the present application, without departing from the technical solutions of the present application, shall still fall within the scope of protection of the technical solutions of the present application.

Claims

1. A method for preparing a high-temperature resistant composite colloid for gelled foods, characterized in that, Includes the following steps: S1. Preparation of modified flaxseed gum: After adding water to flaxseed gum and stirring in a water bath, the pH was adjusted to obtain flaxseed gum solution. Sorbic acid, chitosan acetic acid solution and sodium sulfite solution were added in sequence. Nitrogen gas was introduced throughout the process, and the reaction was carried out by stirring in a constant temperature water bath. After the reaction was completed, the product was poured into anhydrous ethanol to precipitate, vacuum filtered, washed and vacuum dried to obtain modified flaxseed gum. S2. Preparation of zein nanoparticles: The ultrasonically treated zein ethanol solution was dropped into water, rotary evaporated, and the pH was adjusted to obtain a zein nanoparticle solution. S3. Preparation of gel microparticles: Modified flaxseed gum and zein nanoparticle solution were mixed, pH was adjusted, the mixture was placed on a shaker for reaction, homogenized at low speed, and spray-dried to obtain gel microparticles. S4. Preparation of nanocellulose-sodium alginate mixture: After mechanical stirring, the nanocellulose suspension is ultrasonically treated, and the sodium alginate aqueous solution is stirred in a water bath. Then, the nanocellulose suspension and sodium alginate solution are mixed and stirred in a water bath to obtain nanocellulose-sodium alginate mixture. S5. Preparation of chitosan-xyglucan composite solution: The acetic acid solution of chitosan and the xyglucan solution are mixed, vortexed and ultrasonically treated; S6. Preparation of calcium citrate-gallic acid-anthocyanin mixed system: calcium citrate, gallic acid, and anthocyanins were mixed and ultrasonically treated in a water bath; S7. Preparation of composite colloid: The nanocellulose-sodium alginate mixture was mixed and stirred with the chitosan-xyloglucan composite solution. Then, gel microparticles and calcium citrate-gallic acid-anthocyanin mixture were added. The mixture was ultrasonically treated, konjac powder was added and stirring was continued. Then, carrageenan and locust bean gum were added and stirring was continued. Finally, the mixture was refrigerated and allowed to stand to obtain the composite colloid.

2. The method for preparing a high-temperature resistant composite colloid for gelled foods according to claim 1, characterized in that: In step S1, the concentration of the flaxseed gum solution is 5-10 wt.%, and the pH is adjusted to 7; the acetic acid content in the chitosan acetic acid solution is 1-2 wt.%, and the chitosan content is 1-2 wt.%; the concentration of the sodium sulfite solution is 0.1 mol / L; the volume ratio of the flaxseed gum solution, sorbic acid, chitosan acetic acid solution, and sodium sulfite solution is (20-25):(4-6):(5-10):1; the water bath stirring temperature is 50-60℃; the constant temperature water bath temperature is 60-70℃, the stirring speed in the constant temperature water bath is 300-400 rpm, and the reaction time is 3-4 h; the vacuum drying conditions are: temperature 55-65℃, vacuum degree -0.09 MPa.

3. The method for preparing a high-temperature resistant composite colloid for gelled foods according to claim 1, characterized in that: In step S2, the zein content in the zein ethanol solution is 15-25 wt.%, and the ethanol concentration of the ethanol solution is 60-80 wt.%; the power density of the ultrasonic treatment is 200-250 W / cm², the ultrasonic treatment time is 20-40 min, and the ultrasonic treatment temperature is 4-5℃; the mass ratio of the zein ethanol solution to water is (6-8):5; the rotary evaporation temperature is 40-50℃; and the pH is adjusted to 4-5.

4. The method for preparing a high-temperature resistant composite colloid for gelled foods according to claim 1, characterized in that: In step S3, the mass ratio of modified flaxseed gum to zein nanoparticle solution is 1:(4-6); the pH is adjusted to 4-7; the reaction time on a shaker is 20-30 min; the speed of low-speed homogenization is 1000-2000 rpm, and the low-speed homogenization time is 5-10 min.

5. The method for preparing a high-temperature resistant composite colloid for gelled foods according to claim 1, characterized in that: In step S4, the concentration of the nanocellulose suspension is 3wt%-10wt%; the mechanical stirring speed is 500 rpm, and the mechanical stirring time is 20-30 min; the ultrasonic treatment power is 200-300 W, and the time is 10-15 min; the concentration of the sodium alginate solution is 3wt%-10wt%, the water bath temperature is 50-60℃, the stirring speed is 300-400 rpm, and the stirring time is 30-40 min; the mass ratio of the nanocellulose suspension to the sodium alginate solution is (5-10):1, and the water bath stirring time is continued for 1.5-2 h.

6. The method for preparing a high-temperature resistant composite colloid for gelled foods according to claim 1, characterized in that: In step S5, the acetic acid solution of chitosan is the same as above; the concentration of xyloglucan solution is 0.5-1 wt.%; the mass ratio of acetic acid solution of chitosan to xyloglucan solution is 1:(1-2); the vortex stirring speed is 500-600 rpm, and the vortex stirring time is 15-30 min; the ultrasonic treatment power is 500-600 W, and the time is 20-30 min.

7. The method for preparing a high-temperature resistant composite colloid for gelled foods according to claim 1, characterized in that: In step S6, the power of the water bath ultrasound is 300-700W, the time of the water bath ultrasound is 20-25min, and the temperature of the water bath ultrasound is 40-60℃; the content of calcium citrate in the calcium citrate-gallic acid-anthocyanin mixed system is 1-2wt.%, and the content of gallic acid and anthocyanin is 0.1-0.5wt.%.

8. The method for preparing a high-temperature resistant composite colloid for gelled foods according to claim 1, characterized in that: In step S7, the mass ratio of the nanocellulose-sodium alginate mixture, chitosan-xyloglucan composite solution, gel microparticles, calcium citrate-gallic acid-anthocyanin mixture, and konjac flour is (10-15):(15-20):(1-3):(5-15):(30-50); the mass ratio of konjac flour, carrageenan, and locust bean gum is (3-5):(2-3):2; the ultrasonic treatment power is 500-700W, and the time is 20-30min; the refrigerated standing temperature is 4-5℃, and the time is 4-8h.

9. A high-temperature resistant composite colloid for gel food obtained by the preparation method according to any one of claims 1-8.

10. The application of the high-temperature resistant composite colloid for gel food according to claim 9 in the preparation of jelly.

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