阅读说明：本技术 一种凉粉草多糖-大豆分离蛋白复合凝胶的制备方法 (Preparation method of mesona chinensis benth polysaccharide-soybean protein isolate composite gel ) 是由 谢建华 王文洁 申明月 任艳明 余强 陈奕 于 2019-09-24 设计创作，主要内容包括：本发明涉及一种提高凉粉草多糖-大豆分离蛋白复合凝胶的凝胶强度、持水性和热稳定性的制备方法：将凉粉草多糖和大豆分离蛋白分别溶于超纯水中,充分水合,混合,加入促进剂,并加热30min后迅速冷却得到大豆分离蛋白-凉粉草多糖复合凝胶。适宜浓度的盐离子的加入,能显著调节复合凝胶的凝胶强度、持水性和热稳定性。基于复合凝胶良好的凝胶特性以及促进剂的增强作用,得到的复合凝胶可以作为包埋采用。(The invention relates to a preparation method for improving gel strength, water retention and thermal stability of mesona blume polysaccharide-soybean protein isolate composite gel, which comprises the following steps: dissolving herba mesonae chinensis polysaccharide and soybean protein isolate in ultrapure water respectively, fully hydrating, mixing, adding promoter, heating for 30min, and rapidly cooling to obtain soybean protein isolate-herba mesonae chinensis polysaccharide composite gel. The addition of salt ions with proper concentration can obviously adjust the gel strength, the water holding capacity and the thermal stability of the composite gel. Based on the good gel property of the composite gel and the reinforcing effect of the accelerator, the obtained composite gel can be used as embedding.)

1. A preparation method of mesona chinensis benth polysaccharide-soybean protein isolate composite gel is characterized by comprising the following steps:

(1) cleaning fresh mesona blume, drying, crushing, soaking in 80% ethanol overnight, filtering, drying filter residues, extracting the filter residues in 0.2% sodium carbonate solution at 95 ℃ for 2-4h, filtering, precipitating the filtrate with ethanol, filtering, dissolving the precipitate in water, concentrating to one third of the original volume, dialyzing, concentrating, and freeze-drying to obtain mesona blume polysaccharide for later use;

(2) preparing a polysaccharide solution: dissolving the mesona chinensis benth polysaccharide powder in the step (1) in water, wherein the concentration is 1-5%, stirring for 60min, and storing at 4 ℃ for sufficient hydration;

(3) preparation of protein solution: dissolving soybean protein isolate in water at concentration of 5-15%, stirring for 60min, and storing at 4 deg.C for sufficient hydration;

(4) the preparation of the mesona chinensis benth polysaccharide-soybean protein isolate composite gel comprises the following steps: mixing polysaccharide solution and protein solution at 25 deg.C at a ratio of 1: 1-1: 3, adding 0.005-0.005M promoter which is sodium ion or calcium ion solution, stirring for 20-60min at 300rpm of magnetic stirrer, heating the mixture of promoter, mesona chinensis benth polysaccharide and soybean protein isolate at 90-100 deg.C for 30min, cooling to room temperature, and storing at 4 deg.C to form gel.

2. The method for preparing mesona blume polysaccharide-soybean protein isolate composite gel according to claim 1, wherein the accelerator is calcium chloride.

3. The method for preparing mesona blume polysaccharide-soy protein isolate complex gel as claimed in claim 1, wherein the concentration of said accelerant is 0.005M.

4. The method for preparing mesona blume polysaccharide-soybean protein isolate composite gel according to claim 1, wherein the feed-liquid ratio of the mesona blume powder to the ethanol is 1: 5.

Technical Field

The invention relates to the field of food hydrophilic colloids, and in particular relates to a preparation method of mesona blume polysaccharide-soybean protein isolate composite gel.

Background

The mesona blume polysaccharide is a gelatinized anionic polysaccharide extracted from mesona blume. It is an acidic heteropolysaccharide composed of glucose, galactose and galacturonic acid and proteins. The soy protein isolate has excellent functions and high nutritional value, but the soy protein isolate has poor gelling properties. Thus, it is often desirable to add a gelling agent to promote the formation of a soy protein isolate gel. In recent years, polysaccharide gels are receiving wide attention, and mesona chinensis benth polysaccharide has good gel characteristics and has good prospects in promoting the formation of soybean protein isolate as a gel.

The protein-polysaccharide gelation process is generally known as denaturation of proteins during heating, aggregation, and then crosslinking to form a gel. Protein-polysaccharide aggregation relies primarily on interactions between proteins and polysaccharides, including electrostatic interactions, disulfide bonds, hydrogen bonds, and hydrophobic interactions. During gel formation, electrostatic attraction, disulfide bonding, hydrogen bonding and hydrophobic forces need to overcome repulsive forces including peptide chain molecules, peptide chains and polysaccharides. However, because the polysaccharide and protein species differ, the contribution of each interaction is different.

The mesona chinensis benth polysaccharide can form stable composite gel with the isolated soy protein, but the gel strength, the water holding capacity and the thermal stability of the mesona chinensis benth polysaccharide are all insufficient. The formed gel has poor strength, water retention and thermal stability, so that plastic gel is not easy to form and is easily influenced by temperature, and the application of the composite gel in practice is limited.

Disclosure of Invention

The invention aims to provide a preparation method, which can improve the gel strength, water holding capacity and thermal stability of mesona chinensis benth polysaccharide-soybean protein isolate composite gel.

In order to achieve the purpose, the invention adopts the technical scheme that:

a preparation method of mesona chinensis benth polysaccharide-soybean protein isolate (MBP-SPI) composite gel comprises the following steps:

(1) cleaning fresh mesona blume, drying, crushing, soaking in 80% ethanol overnight, filtering, drying filter residues, extracting the filter residues in 0.2% sodium carbonate solution at 95 ℃ for 2-4h, filtering, precipitating the filtrate with ethanol, filtering, dissolving the precipitate in water, concentrating to one third of the original volume, dialyzing, concentrating, and freeze-drying to obtain mesona blume polysaccharide for later use;

(2) preparing a polysaccharide solution: dissolving the mesona chinensis benth polysaccharide powder in the step (1) in water, wherein the concentration is 1-5%, stirring for 60min, and storing at 4 ℃ for sufficient hydration;

(3) preparation of protein solution: dissolving soybean protein isolate in water at concentration of 5-15%, stirring for 60min, and storing at 4 deg.C for sufficient hydration;

(4) the preparation of the mesona chinensis benth polysaccharide-soybean protein isolate composite gel comprises the following steps: mixing polysaccharide solution and protein solution at 25 deg.C at a ratio of 1: 1-1: 3, adding 0.005-0.05M promoter which is sodium ion or calcium ion solution, stirring for 20-60min at 300rpm of magnetic stirrer, heating the mixture of promoter, mesona chinensis benth polysaccharide and soybean protein isolate at 90-100 deg.C for 30min, cooling to room temperature, and storing at 4 deg.C to form gel.

Further, the accelerator is calcium chloride.

Further, the concentration of the accelerator was 0.005M.

Furthermore, the feed-liquid ratio of the mesona blume powder to the ethanol is 1: 5.

Compared with the prior art, the invention has the beneficial effects that:

(1) the mesona chinensis benth polysaccharide-soybean protein isolate composite gel prepared by the method has good gel strength, water retention and thermal stability;

(2) the mesona chinensis benth polysaccharide-soybean protein isolate composite gel prepared by the method has the advantages of uniform and compact microstructure, small pores and smooth surface.

(3) The mesona chinensis benth polysaccharide-soybean protein isolate composite gel prepared by the method has better plasticity and wider utilization space.

Drawings

FIG. 1 is a graph showing the effect of salt ions on the water binding capacity of a complex gel;

FIG. 2 is a graph of the effect of salt ions on composite gel strength;

FIG. 3 is a graph showing the effect of salt ions on the thermal stability of a composite gel.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.