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CN-121986925-A - Preparation method and application of pH-responsive bromhidrosis polysaccharide-soybean protein isolate composite gel

CN121986925ACN 121986925 ACN121986925 ACN 121986925ACN-121986925-A

Abstract

The invention discloses a preparation method and application of pH response type bromhidrosis polysaccharide-soy isolate protein composite gel. The preparation method comprises extracting bromhidrosis Chai Duotang, preparing stock solution, preparing soybean protein isolate solution, mixing the above two solutions, adjusting pH to 3.0-9.0, heating for gelation, cooling and solidifying to obtain composite gel. The gel has optimal performance, especially pH3.0, water holding capacity of more than or equal to 62%, storage modulus of 920Pa, high gel strength, good thermal stability, stable structure, no need of chemical cross-linking agent in the preparation process and natural raw materials. The composite gel can be widely applied to the field of food processing, such as jelly serving as a gel matrix, can effectively improve the water holding capacity, the taste stability and the nutritional value of the product, and provides an effective solution for high-value utilization of natural plant polysaccharide and protein and development of novel functional foods.

Inventors

  • Yang Ningxian
  • WANG SIYU
  • Mao Runbo
  • WANG DAOPING
  • LI YUCHAO
  • HE JING
  • LIU CHANGRUI

Assignees

  • 贵州医科大学

Dates

Publication Date
20260508
Application Date
20260227

Claims (10)

  1. 1. The preparation method of the pH response type bromhidrosis polysaccharide-soy isolate protein composite gel is characterized by comprising the following steps of: (1) Extracting bromhidrosis polysaccharide, namely sun-drying fresh bromhidrosis Chai Shepian, crushing, sieving with a 60-100 sieve to obtain bromhidrosis powder, mixing the bromhidrosis powder with ultrapure water according to the mass ratio of 1:10-50, adjusting the pH value to 1-5 with tartaric acid, extracting for 30-90min in a 70-110 ℃ water bath, stirring once every 10min, filtering, adding 95% ethanol with the volume of 1-4 times of the filtrate into the filtrate, standing for 80-150min after stirring uniformly, centrifuging for 8-25min at the revolution of 5000-10000r/min, pre-freezing the collected precipitate at-20 ℃ for 18-29h, vacuum drying for 18-29h, and grinding into powder to obtain the bromhidrosis polysaccharide extract for standby; (2) Preparing bromhidrosis polysaccharide solution by dissolving bromhidrosis polysaccharide extract in ultrapure water, magnetically stirring at 18-36 deg.C for 90-140min at 300-700r/min, and standing at 0-10 deg.C overnight for hydration to obtain bromhidrosis Chai Duotang-15% stock solution; (3) Preparing soybean protein isolate solution, namely dissolving soybean protein isolate powder in ultrapure water, magnetically stirring for 90-140min at 18-36 ℃ and 300-700r/min, and standing for overnight dissolution at 0-10 ℃ to obtain 22-52% soybean protein isolate solution for later use; (4) preparing a pH response type bromhidrosis polysaccharide-soybean protein isolate mixed solution, namely mixing the bromhidrosis Chai Duotang stock solution in the step (2) and the soybean protein isolate solution in the step (3) according to the volume ratio of 1:0.5-2, stirring for 10-50min by using a magnetic force with the revolution of 100-500r/min until the mixture is uniform, and regulating the pH to 3.0-9.0 to obtain the pH response type bromhidrosis polysaccharide-soybean protein isolate mixed solution for later use; (5) And (3) thermal gelation, namely placing the pH response type bromhidrosis polysaccharide-soybean protein isolate mixed solution obtained in the step (4) in a water bath at 65-145 ℃ for heating for 15-65min, then cooling the mixed solution to room temperature with ice and water, sealing and then refrigerating the mixed solution at 0-10 ℃ for overnight to obtain the bromhidrosis Chai Duotang-soybean protein isolate composite gel.
  2. 2. The method for preparing the pH-responsive bromhidrosis polysaccharide-soy protein isolate composite gel according to claim 1, wherein in the step (1), the bromhidrosis polysaccharide is extracted by sun-drying fresh bromhidrosis Chai Shepian, crushing, sieving with a 70-90-mesh sieve to obtain bromhidrosis powder, mixing the bromhidrosis powder with ultrapure water according to the mass ratio of 1:20-40, adjusting the pH to 2-3 by tartaric acid, extracting in a 77-95 ℃ water bath for 50-70min, stirring once every 10min, filtering, adding 95% ethanol with 2-3 times of the volume of the filtrate into the filtrate, standing for 100-135min after stirring uniformly, centrifuging for 11-19min at the revolution of 6500-9200r/min, pre-freezing the collected precipitate at-20 ℃ for 21-27h, vacuum drying for 21-27h, and grinding into powder to obtain the bromhidrosis polysaccharide extract.
  3. 3. The method for preparing the pH-responsive bromhidrosis polysaccharide-soy protein isolate composite gel according to claim 2, wherein in the step (1), the bromhidrosis polysaccharide is extracted by sun-drying fresh bromhidrosis Chai Shepian, crushing, sieving with a 80-mesh sieve to obtain bromhidrosis powder, mixing the bromhidrosis powder with ultrapure water according to the mass ratio of 1:30, adjusting the pH to 2 by tartaric acid, extracting for 1h in a 90 ℃ water bath, stirring once every 10min during the extraction, filtering, adding 95% ethanol with the volume of 2 times of the filtrate into the filtrate, standing for 2h after stirring uniformly, centrifuging at the revolution of 8000r/min for 15min, and placing the collected precipitate in a vacuum for drying for 24h after pre-freezing at-20 ℃, and grinding into powder to obtain the bromhidrosis polysaccharide extract.
  4. 4. The method for preparing the pH-responsive bromhidrosis polysaccharide-soy protein isolate composite gel according to claim 1, wherein in the step (2), bromhidrosis Chai Duotang stock solution is prepared by dissolving bromhidrosis polysaccharide extract in ultrapure water, placing the solution in magnetic stirring at 25 ℃ for 2 hours with the rotation speed of 500r/min, and then placing the solution in 4 ℃ for overnight hydration to obtain bromhidrosis polysaccharide solution with the concentration of 9%, wherein the purity of the bromhidrosis Chai Duotang stock solution is more than or equal to 85% based on the polysaccharide content.
  5. 5. The method for preparing the pH-responsive bromhidrosis polysaccharide-soy protein isolate composite gel according to claim 1, wherein in the step (3), soy protein isolate solution is prepared by dissolving soy protein isolate powder in ultrapure water, magnetically stirring the solution for 2 hours at a temperature of 25 ℃ and a revolution of 500r/min, and then standing the solution at a temperature of 4 ℃ overnight for dissolution, so as to obtain a soy protein isolate solution with a concentration of 34%, wherein the protein content of the soy protein isolate solution is more than or equal to 90%.
  6. 6. The method for preparing the pH-responsive bromhidrosis polysaccharide-soy protein isolate composite gel according to claim 1, wherein in the step (4), the pH-responsive bromhidrosis polysaccharide-soy protein isolate mixed solution is prepared by mixing the bromhidrosis Chai Duotang stock solution in the step (2) and the soy protein isolate solution in the step (3) according to a volume ratio of 1:0.8-1.5, and magnetically stirring for 20-40min at a revolution of 200-400r/min until the mixture is uniform, and then adjusting the pH to 3.0-5.0 to obtain the pH-responsive bromhidrosis polysaccharide-soy protein isolate mixed solution.
  7. 7. The method for preparing the pH-responsive bromhidrosis polysaccharide-soybean protein isolate composite gel according to claim 6, wherein in the step (4), the pH-responsive bromhidrosis polysaccharide-soybean protein isolate mixture is prepared by mixing the bromhidrosis Chai Duotang stock solution in the step (2) and the soybean protein isolate solution in the step (3) according to a volume ratio of 1:1, stirring for 30min to uniformity by using a magnetic force with a revolution of 300r/min, and then adjusting the pH to 3.0 to obtain the pH-responsive bromhidrosis polysaccharide-soybean protein isolate mixture.
  8. 8. The method for preparing the pH-responsive bromhidrosis polysaccharide-soy protein isolate composite gel according to claim 1, wherein in the step (5), the pH-responsive bromhidrosis polysaccharide-soy protein isolate mixed solution in the step (4) is put into a water bath with the temperature of 88-120 ℃ and heated for 25-45min, then the water bath with ice and water is cooled to the room temperature, and the bromhidrosis Chai Duotang-soy protein isolate composite gel is obtained after sealing and refrigerating overnight at the temperature of 2-7 ℃.
  9. 9. The method for preparing the pH-responsive bromhidrosis polysaccharide-soy protein isolate composite gel according to claim 8, wherein in the step (5), the pH-responsive bromhidrosis polysaccharide-soy protein isolate mixed solution in the step (4) is heated in a water bath at 95 ℃ for 30min, then is cooled to room temperature by ice and water, and is refrigerated overnight at 4 ℃ after sealing, so that the bromhidrosis Chai Duotang-soy protein isolate composite gel is obtained, and the water content of the bromhidrosis Chai Duotang-soy protein isolate composite gel is more than or equal to 62.0%.
  10. 10. The application of the pH response type bromhidrosis polysaccharide-soybean protein isolate composite gel in preparing a food processing gel matrix is characterized in that when the food is jelly, the addition amount of the composite gel is 10% -30% of the total mass of the jelly, and the composite gel is used for improving the water holding capacity and the taste stability of the jelly.

Description

Preparation method and application of pH-responsive bromhidrosis polysaccharide-soybean protein isolate composite gel Technical Field The invention belongs to the technical field of food gel materials, and particularly relates to a preparation method and application of pH response type bromhidrosis polysaccharide-soy protein isolate composite gel. Background The bromhidrosis (Premna puberula Pamb.) is perennial upright shrub of Premnaceae, and is naturally distributed in Guizhou, yunnan, sichuan provinces in southwest China, and mostly exists in a wild state. The leaves are rich in active ingredients such as pectin, protein, mineral substances, flavone, polyphenol and the like, and have high medicinal and edible values. However, the leaves themselves have a special smell, so that the edible acceptance and processing adaptability of the leaves are obviously limited, and the leaves are developed and utilized in a low-level state for a long time. The traditional food "the immortal bean curd" is only used in the remote areas of Guizhou and Yunnan, has simple process and single form, is used for preparing the traditional food, and is not used for effectively utilizing a large amount of wild and cultivated resources, so that the obvious waste of natural functional raw materials is caused. Bromhidrosis Chai Duotang (Premna puberula leaves Polysaccharides, PLP) is mainly extracted from vegetative organs such as leaves, and is an important functional component in bromhidrosis firewood. The polysaccharide is easy to dissolve in water, insoluble in organic solvents such as ethanol and acetone, the aqueous solution is sticky, has no obvious peculiar smell, has excellent water solubility, biocompatibility and chemical stability, shows various biological activities such as antioxidation, anti-inflammatory, immunoregulation and the like, and has the potential of being used as a functional food matrix. However, the gel performance of the gel has obvious short plates, a single polysaccharide system is difficult to spontaneously form three-dimensional network gel with complete structure and stable mechanical property, and the viscoelasticity, the water retention and the structural integrity are not ideal, so that the gel has limited application as a gel matrix in improving food quality. At present, research is focused on optimization of an extraction process and evaluation of medicinal activity, systematic exploration aiming at gel behavior and food processing suitability is not seen, and no report is given on the fact that the gel is compounded with soy isolate protein through a specific process to construct high-performance composite gel with pH response regulation and control capability, so that functional value cannot be effectively released. The soybean protein isolate (Soy Protein Isolate, SPI) is a high-purity plant protein prepared by taking soybeans as raw materials through processes of extraction, separation, purification, drying and the like, has the protein content of more than 90%, has good solubility, emulsifying property, foamability and water absorption expansibility, can form a gel system under certain conditions, and is a plant protein matrix and gel material widely applied in the food industry. However, the single SPI gel system has the defects of insufficient gel strength, poor water retention, fragile structure and the like, and in addition, the gel stability is highly sensitive to the external environment, and particularly under the conditions of acidity, high temperature or high ionic strength, the gel network is easy to degrade, shrink or disintegrate, so that the independent application of the gel system in a complex food system is limited. In recent years, composite gel materials constructed based on the combination of natural polysaccharide and protein have the function complementarity and texture control potential of both components, and become research hot spots in the field of food gel. At present, the gel system for industrialized application mainly comprises carrageenan-protein composite gel, pectin-starch gel and the like, wherein polysaccharide components are mainly derived from red algae extraction or fruit and vegetable processing byproducts, and protein components are usually derived from whey protein, gelatin or soybean protein and the like. The gel material improves the texture characteristics and stability of foods to a certain extent, and can be applied to jelly, yoghurt, meat products and the like. However, the existing system still commonly faces the common bottlenecks that firstly, a gel structure is highly sensitive to pH, particularly under acidic conditions (such as pH is less than or equal to 4.5), a gel network is easy to dissociate and shrink, deterioration phenomena such as dehydration, cracking and softening occur, and the performance is difficult to maintain in a wide pH range, secondly, in order to enhance the strength and structural stability of the gel, the existing tec