Preparation method of peanut protein gel with low allergenicity and high stability

Abstract

This invention discloses a method for preparing a low-allergenic and highly stable peanut protein gel, belonging to the field of food processing technology. This invention utilizes a synergistic strategy of combining physical-chemical coupling pretreatment and laccase-catalyzed cross-linking of pyrogallol structural polyphenols. This makes peanut protein more readily acted upon by laccase, facilitates the entry of pyrogallol polyphenols into the protein network, and results in more uniform and complete enzymatic cross-linking, ultimately yielding a peanut protein gel with excellent gel strength and stability and lower allergenicity. Specifically, the synergistic effect of the physical / chemical coupling pretreatment ensures more thorough depolymerization of peanut protein and more complete molecular chain extension, exposing numerous reaction sites and laying the foundation for subsequent laccase-induced cross-linking of peanut protein with pyrogallol structural polyphenols to prepare the gel. Under laccase catalysis, the pyrogallol structural polyphenols are oxidized to polyquinone intermediates with more cross-linking sites, which bind to the active sites of the pretreated and modified peanut protein, ultimately forming a dense three-dimensional network structure peanut protein gel.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, and in particular to a method for preparing a low-allergenic and highly stable peanut protein gel. Background Technology

[0002] Peanuts are an important oilseed crop in my country, and peanut protein is a high-quality plant protein resource with a reasonable amino acid composition and high biological value. Gel-forming ability is one of the important functional properties of proteins, directly affecting their application in meat products, gelled foods, and dairy products. However, natural peanut protein has relatively weak gel-forming ability, usually requiring a high concentration to form a gel, and its gel strength and water-holding capacity need improvement. Furthermore, peanut protein contains a high proportion of allergens, limiting its large-scale application in the food industry.

[0003] Currently, reported methods for improving protein gel properties mainly include physical modification (such as ultrasound, dynamic high-pressure microfluidics, and microwave), chemical modification (such as pH shifting), and enzymatic modification. However, existing studies have shown that while physical or chemical modifications can partially unfold the protein structure and expose the active sites and functional groups of peanut protein, the degree of exposure of active sites is limited by single modification techniques, resulting in low efficiency of subsequent enzyme cross-linking.

[0004] Laccase is a polyphenol oxidase that has shown great potential in the field of food molecular modification.

[0005] The mechanism of laccase-catalyzed protein cross-linking is as follows: firstly, it catalyzes the oxidation of polyphenols to generate highly active quinone intermediates. These intermediates then undergo non-enzymatic reactions with nucleophilic amino acid residues on protein molecules, forming a protein-polyphenol-protein covalent cross-linked network. Studies have shown that when using laccase to cross-link peanut protein with monophenols / bisphenols, the limited number of cross-linking sites of phenols easily leads to a loose gel network with low strength and poor stability. Pyrogallol is an excellent substrate for laccase. As a polyphenol compound, it has three ortho-hydroxyl groups, which, upon oxidation, can generate highly active quinone structures (polyquinone intermediates) with multiple cross-linking reaction sites, thus enabling multi-site cross-linking with protein molecules. However, the single laccase-polyphenol cross-linking technology also faces challenges. The tightly packed spherical structure of untreated peanut protein encapsulates the active sites, thus limiting its full binding with polyphenol mediators (polyquinone intermediates) and enzyme action sites.

[0006] In view of this, the present invention prepares a composite peanut protein gel by integrating physical field pretreatment, chemical environment regulation and laccase-catalyzed cross-linking of pyrogallol structural polyphenols through a multi-technology synergistic strategy, so as to achieve a breakthrough in the performance of peanut protein gel. Summary of the Invention

[0007] The purpose of this invention is to provide a method for preparing a peanut protein gel with low allergenicity and high stability.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A method for preparing a low-allergenicity, highly stable peanut protein gel includes the following steps: S1. The peanut protein dispersion is modified by a physical / chemical coupling pretreatment; wherein the physical / chemical coupling pretreatment modification is performed by first subjecting the peanut protein dispersion to ultrasonic treatment, dynamic high-pressure microfluidic treatment, or microwave treatment, followed by pH shifting combined with mild heat treatment. This step can provide more active sites for the subsequent preparation of gels by cross-linking peanut protein with laccase-induced pyrogallol-structured polyphenols.

[0010] S2, Synergistic cross-linking: Add pyrogallol-structured polyphenols and laccase to the pretreated peanut protein system to carry out an enzyme-catalyzed oxidative cross-linking reaction; S3. The product of the enzyme-catalyzed oxidative cross-linking reaction is heated to induce gelation, and then cooled to obtain peanut protein gel. In this process, heating causes the peanut protein to stretch, exposing the internal hydrophobic groups and thiol groups, providing reaction sites for subsequent cross-linking; cooling causes the peanut protein to re-aggregate through hydrogen bonds, hydrophobic interactions, disulfide bonds, etc., to form a three-dimensional network structure, i.e., gel. The cooling process helps to "lock" the network, making the formed gel more stable.

[0011] Preferably, in step S1, the mass percentage concentration of the peanut protein dispersion is 5-15%.

[0012] Preferably, the ultrasonic treatment power is 200-800W, the treatment time is 5-20 min, and the system temperature is controlled to not exceed 40℃.

[0013] Preferably, the homogenization pressure during the dynamic high-pressure microjet treatment is 30-150 MPa, and the number of cycles is 1-3.

[0014] Preferably, the microwave power during microwave processing is 400-600 W, the temperature is 50-70℃, and the microwave processing time is 2-6 min.

[0015] Preferably, the pH shift combined with mild heat treatment is performed by: performing pH shift treatment on the protein, followed by heat treatment, and then adjusting the pH of the heat-treated solution to neutral.

[0016] Preferably, the pH shift treatment conditions are: pH 9.0-12.0, time 5-30 min; Preferably, the heat treatment conditions are: temperature of 40-80℃ and time of 30-120min.

[0017] Preferably, in step S2, the pyrogallol-structured polyphenols include, but are not limited to, gallocatechin, epigallocatechin, delphinidin, and myricetin.

[0018] Preferably, the amount of the pyrogallol-structured polyphenol added is 0.1-3.0% of the peanut protein content.

[0019] Preferably, the amount of laccase added is 5-80 U / g protein, the pH is 5.5-7.5, the temperature of the enzyme-catalyzed oxidative cross-linking reaction is 25-55℃, and the reaction time is 1-8 h.

[0020] Preferably, in step S3, the heating temperature is 80-95℃ and the heating time is 5-10 min.

[0021] Beneficial effects 1. This invention provides a method for preparing a low-allergenic and highly stable peanut protein gel. By integrating a physicochemical coupling pretreatment and a synergistic strategy of laccase-catalyzed cross-linking of pyrogallol structural polyphenols, peanut protein is more easily acted upon by laccase, pyrogallol polyphenols more easily enter the protein network, and enzymatic cross-linking is more uniform and complete, ultimately yielding a peanut protein gel with excellent gel strength and stability and lower allergenicity. Among these, (1) In the physical / chemical coupling pretreatment, physical modification treatment (ultrasound, microwave, dynamic high pressure microjet treatment): (a) Ultrasound treatment destroys the secondary structure of peanut protein through cavitation effect, causing peanut protein molecules to unfold and expose the active sites of amino / thiol / phenolic hydroxyl crosslinking; (b) Microwave treatment destroys the secondary structure of peanut protein through the synergistic effect of "thermal effect" and "non-thermal effect", causing the protein to unfold and expose the internal hydrophobic groups and active sites; (c) Dynamic high pressure microjet (DHPM) treatment destroys the hydrogen bonds and hydrophobic interactions of the protein through high-speed shearing, cavitation effect and jet impact, causing its secondary structure to unfold and expose more active sites; Chemical modification treatment (i.e. pH shift combined with mild heat treatment) can further destroy the hydrogen bonds and disulfide bonds in the protein molecules, so that the active sites such as lysine amino and cysteine ​​thiol are fully exposed, providing more reaction site basis for subsequent crosslinking reaction. The synergistic effect of physical / chemical coupling pretreatment not only enables controllable, efficient, and mild modification of peanut protein structure under mild conditions, but also allows for more thorough protein depolymerization, more complete molecular chain extension, and extensive exposure of reaction sites, laying the foundation for subsequent laccase-induced cross-linking of pyrogallol-structured polyphenols with peanut protein to prepare gels.

[0022] (2) The trihydroxy structure of the pyrogallol polyphenol is oxidized to a polyquinone intermediate under the catalysis of laccase. Compared with existing monophenols / bisphenols, it can provide more cross-linking sites and greatly improve the cross-linking density. The peanut protein modified by pretreatment binds precisely to the polyquinone intermediate through its active sites to form stable CN and CS covalent bonds. At the same time, the protein molecules generate physical entanglement due to unfolding, and finally form a uniform, dense, three-dimensional network structure. This structure synergistically improves the strength and stability of the gel.

[0023] 2. The preparation method of this invention is simple and suitable for large-scale industrial production. Attached Figure Description

[0024] Figure 1 UV images of peanut protein gels prepared in Examples 1-9 and Comparative Examples 1-7; Figure 2 The graph shows a comparison of the gel strength of peanut protein gels prepared in Examples 1-9 and Comparative Examples 1-7. Figure 3 The graph shows the IgE binding capacity of peanut protein gels prepared in Examples 1-9 and Comparative Examples 1-7. Figure 4 Scanning electron microscope images of peanut protein gels prepared in Examples 1-9 and Comparative Examples 1-7. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0026] Example 1 This embodiment provides a method for preparing a low-allergenicity and highly stable peanut protein gel, wherein the pretreatment employs a combination of ultrasonic treatment and pH shifting with gentle heat treatment, including the following steps: S1. Mix peanut protein raw material with deionized water, stir evenly, and prepare a protein dispersion with a mass percentage concentration of 10%; then treat the obtained protein dispersion with ultrasound (power 500 W) for 10 min; then adjust the pH of the protein dispersion to 10.0, treat it in a 50℃ water bath for 60 min, and then adjust the pH to 7.0. S2. Add gallic catechin to the pretreated modified protein dispersion at an amount of 1.0% of the peanut protein mass, stir evenly to obtain a mixture; add laccase to the obtained mixture at an amount of 20 U / g protein, adjust the pH to 6.5, and react in a 35℃ water bath for 4 hours. S3. Heat the reacted gel to 90°C, keep it warm for 10 min, and then cool it at 4°C for 12 h to obtain peanut protein gel.

[0027] Example 2 This embodiment provides a method for preparing a low-allergenicity and highly stable peanut protein gel, wherein the pretreatment employs a combination of dynamic high-pressure microfluidic treatment and pH shifting with gentle heat treatment, including the following steps: S1. Physical / chemical modification pretreatment: Peanut protein raw material is mixed with deionized water and stirred evenly to prepare a peanut protein dispersion with a mass percentage concentration of 10%. The peanut protein dispersion is circulated twice and subjected to dynamic high-pressure micro-jet treatment at 100 MPa pressure. The pH of the protein dispersion is then adjusted to 10.0 and treated in a 50℃ water bath for 60 min. Finally, the pH is adjusted to 7.0. S2. Epigallocatechin was added to the pretreated modified protein dispersion at a concentration of 1.0% of the peanut protein mass. The mixture was stirred until homogeneous to obtain a solution. Laccase was added to the solution at a concentration of 25 U / g protein. The pH was adjusted to 6.0 and the mixture was reacted in a 35°C water bath for 4 hours. S3. Heat the reacted gel to 90℃, keep it at that temperature for 12 min, and then cool it at 4℃ for 12 h to obtain peanut protein gel.

[0028] Example 3 This embodiment provides a method for preparing a low-allergenicity and highly stable peanut protein gel, wherein the pretreatment adopts a combination of microwave pretreatment and pH shifting combined with mild heat treatment, including the following steps: S1. Mix peanut protein raw material with deionized water, stir evenly, and prepare a protein dispersion with a mass percentage concentration of 10%; microwave the obtained protein dispersion with a microwave power of 500 W, a temperature of 60℃, and a treatment time of 4 min; then adjust the pH of the protein dispersion to 10.0, treat it in a 50℃ water bath for 60 min, and then adjust the pH to 7.0. S2. Add delphinidin to the pretreated and modified protein dispersion at an amount equal to 1.2% of the peanut protein mass, stir until homogeneous, and obtain a mixture. Add laccase to the mixture at an amount of 30 U / g protein, adjust the pH to 6.5, and react in a 40℃ water bath for 5 hours. S3. Heat the reacted gel to 95°C, keep it warm for 10 min, and then cool it at 4°C for 12 h to obtain peanut protein gel.

[0029] Example 4 S1. Mix peanut protein raw material with deionized water, stir evenly, and prepare a protein dispersion with a mass percentage concentration of 15%; then treat the obtained protein dispersion with ultrasound (power 750 W) for 20 min; then adjust the pH of the protein dispersion to 11.0, treat it in a 70℃ water bath for 100 min, and then adjust the pH to 7.0. S2. Epigallocatechin was added to the pretreated modified protein dispersion at a concentration of 1.0% of the peanut protein mass. The mixture was stirred until homogeneous to obtain a solution. Laccase was added to the solution at a concentration of 20 U / g protein. The pH was adjusted to 6.5 and the mixture was reacted in a 35°C water bath for 4 hours. S3. Heat the reacted gel to 90°C, keep it warm for 10 min, and then cool it at 4°C for 12 h to obtain peanut protein gel.

[0030] Example 5 S1. Physical / chemical modification pretreatment: Mix peanut protein raw material with deionized water, stir evenly, and prepare a peanut protein dispersion with a mass percentage concentration of 5%. Circulate the peanut protein dispersion twice and treat it with dynamic high-pressure microjet at 40 MPa. Then adjust the pH of the protein dispersion to 9.0, treat it in a 50℃ water bath for 30 min, and then adjust the pH to 7.0. S2. Add gallic catechin to the pretreated modified protein dispersion at a concentration of 0.2% of the peanut protein mass, stir until homogeneous, and obtain a mixture. Add laccase to the mixture at a concentration of 5 U / g protein, adjust the pH to 6.0, and react in a 30℃ water bath for 4 hours. S3. Heat the reacted gel to 90℃, keep it at that temperature for 12 min, and then cool it at 4℃ for 12 h to obtain peanut protein gel.

[0031] Example 6 S1. Mix peanut protein raw material with deionized water, stir evenly, and prepare a protein dispersion with a mass percentage concentration of 10%; microwave the obtained protein dispersion at a microwave power of 450 W, a temperature of 70℃, and a treatment time of 6 min; then adjust the pH of the protein dispersion to 12.0, treat it in an 80℃ water bath for 30 min, and then adjust the pH to 7.0. S2. Add myricetin to the pretreated modified protein dispersion at an amount of 1.2% of the peanut protein mass, stir evenly to obtain a mixture; add laccase to the obtained mixture at an amount of 30 U / g protein, adjust the pH to 6.5, and react in a 40℃ water bath for 5 hours. S3. Heat the reacted gel to 95°C, keep it warm for 10 min, and then cool it at 4°C for 12 h to obtain peanut protein gel.

[0032] Example 7 S1. Mix peanut protein raw material with deionized water, stir evenly, and prepare a protein dispersion with a mass percentage concentration of 10%; then treat the obtained protein dispersion with ultrasound (power 500 W) for 10 min; then adjust the pH of the protein dispersion to 10.0, treat it in a 50℃ water bath for 60 min, and then adjust the pH to 7.0. S2. Add delphinidin to the pretreated and modified protein dispersion at a concentration of 1.0% of the peanut protein mass, stir until homogeneous, and obtain a mixture. Add laccase to the mixture at a concentration of 20 U / g protein, adjust the pH to 6.5, and react in a 35℃ water bath for 4 hours. S3. Heat the reacted gel to 90°C, keep it warm for 10 min, and then cool it at 4°C for 12 h to obtain peanut protein gel.

[0033] Example 8 S1. Physical / chemical modification pretreatment: Peanut protein raw material is mixed with deionized water and stirred evenly to prepare a peanut protein dispersion with a mass percentage concentration of 10%. The peanut protein dispersion is circulated 3 times and subjected to dynamic high-pressure micro-jet treatment at 50 MPa pressure. The pH of the protein dispersion is then adjusted to 10.0 and treated in a 50℃ water bath for 110 min. Finally, the pH is adjusted to 7.0. S2. Add delphinidin to the pretreated and modified protein dispersion at a concentration of 0.1% of the peanut protein mass, stir until homogeneous, and obtain a mixture. Add laccase to the mixture at a concentration of 5 U / g protein, adjust the pH to 5.5, and react in a 25°C water bath for 1 hour. S3. Heat the reacted gel to 90°C, keep it warm for 5 min, and then cool it at 4°C for 12 h to obtain peanut protein gel.

[0034] Example 9 S1. Mix peanut protein raw material with deionized water, stir evenly, and prepare a protein dispersion with a mass percentage concentration of 10%; microwave the obtained protein dispersion with a microwave power of 500 W, a temperature of 65℃, and a treatment time of 5 min; then adjust the pH of the protein dispersion to 11.0, treat it in a 70℃ water bath for 40 min, and then adjust the pH to 7.0. S2. Epigallocatechin was added to the pretreated modified protein dispersion at a concentration of 1.0% of the peanut protein mass. The mixture was stirred until homogeneous to obtain a solution. Laccase was added to the solution at a concentration of 20 U / g protein. The pH was adjusted to 6.5 and the mixture was reacted in a 45°C water bath for 6 hours. S3. Heat the reacted gel to 90°C, keep it at that temperature for 8 min, and then cool it at 4°C for 12 h to obtain peanut protein gel.

[0035] Comparative Example 1 The steps are basically the same as in Example 1, except that: in step S1, (high-intensity) ultrasonic treatment and pH shifting combined with mild heat treatment are not performed; and in step S2, gallic catechin and laccase are not added.

[0036] Comparative Example 2 The steps are basically the same as in Example 1, except that gallocatechin and laccase are not added in step S2.

[0037] Comparative Example 3 The steps are basically the same as in Example 1, except that: in step S1, high-intensity ultrasonic treatment and pH shifting combined with mild heat treatment are not performed; and in step S2, laccase is not added.

[0038] Comparative Example 4 The steps are basically the same as in Example 1, except that high-intensity ultrasonic treatment is not performed in step S1.

[0039] Comparative Example 5 The steps are basically the same as in Example 1, except that gallocatechin is not added in step S2.

[0040] Comparative Example 6 The steps are basically the same as in Example 1, except that laccase is not added in step S2.

[0041] Comparative Example 7 The steps are basically the same as in Example 1, except that pH shifting combined with mild heat treatment is not performed in step S1.

[0042] Performance testing (1) Determination of peanut gel structure The absorbance of the peanut protein gels prepared in Examples 1-3 and Comparative Examples 1-7 was measured using a UV spectrophotometer at 250-350 nm. The results are as follows: Figure 1 As shown.

[0043] Depend on Figure 1 The results showed that the UV absorption of Comparative Examples 1-7 was significantly lower than that of Examples 1-9, indicating that the chromophores migrated to the protein surface after treatment in these examples. On the other hand, the enhanced UV absorption of polyphenols, due to their strong UV absorption, may be due to the binding of polyphenols.

[0044] (2) Determination of peanut protein gel-bound polyphenol content 1 g of peanut protein gel prepared in Examples 1-9 was mixed with 30 mL of 70% ethanol solution and sonicated for 15 min at 47℃ and 240 W. After centrifugation at 6000 rpm for 15 min, the supernatant was collected. The precipitate was mixed with 50 mL of 80% ethanol solution and sonicated for a second extraction. The two supernatants were combined, and 1 mL of the extract was transferred to a 10 mL centrifuge tube. 0.5 mL of Folin-Ciocalteu was added, and the mixture was shaken and reacted for 3 min. Then, 2 mL of 7.5% (w / v) sodium carbonate solution and 6.5 mL of distilled water were added, and the mixture was shaken and reacted for 1 min. The mixture was then placed in the dark and reacted for 1 h. The absorbance was measured at 765 nm using a UV spectrophotometer. The results are as follows. Figure 2 As shown.

[0045] Depend on Figure 2 The results showed that the polyphenols in Examples 1-9 were effectively bound to peanut protein, indicating that the physical / chemical modification pretreatment of peanut protein can provide more binding sites, resulting in the immobilization of most polyphenols on peanut protein under the action of laccase.

[0046] (3) Sensitization test of peanut protein gel The peanut protein gels prepared in Examples 1-9 and Comparative Examples 1-7 were diluted to 1 μg / mL with coating buffer (0.015 mol / L Na2CO3, 0.035 mol / L NaHCO3, pH=9.6) and added to the microplate at a volume of 100 μL per well. Each sample group was set up in 3 replicates and coated at 4℃ for 12 h. Add 100 μL of 0.01 mol / L PBS-T washing buffer (0.01 mol / L PBS, 0.05% Tween-20) to each well, wash the sample thoroughly, and discard the buffer. Repeat 3 times. Add 200 μL of blocking buffer (0.1% BSA) to each well, block at 37°C for 2 h, and then wash 3 times with PBS-T. Add 100 μL of peanut allergy serum diluted 1:10 with blocking buffer to each well, and incubate at 37°C for 2 h. After incubation and washing, add 100 μL of HRP-labeled goat anti-human IgE secondary antibody (diluted 1:10000 with blocking buffer) to each well and incubate at 37°C for 1 h. After washing again with PBS-T, 150 μL of TMB substrate reaction solution was added, and the mixture was incubated at 37°C in the dark for 15 min. The reaction was then terminated by adding 50 μL of 2 mol / L H₂SO₄. The absorbance of each well was measured at 450 nm. The results are as follows: Figure 3 As shown, a higher OD value indicates a stronger allergenicity of the prepared peanut protein powder.

[0047] Depend on Figure 3The results showed that, compared with comparative examples 1-7 which had higher IgE binding capacity, examples 1-9 all exhibited significantly reduced IgE binding capacity. This is partly because the physical / chemical modification pretreatment partially destroyed the original peanut protein antigenic epitopes, and partly because the effective binding of polyphenols formed stable intraprotein cross-links, further masking the remaining antigenic epitopes and reducing the likelihood of IgE recognition.

[0048] (4) Peanut protein gel strength determination Peanut protein gels prepared in Examples 1-9 and Comparative Examples 1-7 were cut into 1 cm³ cubes and subjected to compression tests using a P36R probe (36 mm diameter, stainless steel cylinder). The initial and test speeds were 1 mm / s, and the post-test speed was 5 mm / s. The maximum compressive strain was 90%, and the trigger force was 5 g. The stress-strain curve was recorded by a computer during compression. The Young's modulus of the sample was obtained by calculating the slope of the linear region (strain range 5%-15%) of the stress-strain curve. Gel samples were prepared into 4 cm × 4 cm × 2 cm blocks and subjected to uniaxial compression tests using a texture analyzer. A P0.5R probe (0.5 inch diameter, black cylinder) was used for compression tests. The experimental parameters were set as follows: initial speed 1 mm / s, test speed 0.5 mm / s, post-test speed 10 mm / s, compression depth 10 mm, and trigger force 5 g. The force-displacement curve was recorded by the instrument software, and the maximum force value was taken as the hardness of the gel. The results are shown in Table 1.

[0049] Table 1. Texture properties of peanut protein gel

[0050] As shown in Table 1, compared to Comparative Examples 1-7, Examples 1-9 exhibited significantly increased texture parameters such as hardness, elasticity, cohesiveness, and chewiness under the combined effects of physical / chemical modification pretreatment and enzyme-induced pyrogallol crosslinking. This is because the physical / chemical modification pretreatment promotes the full unfolding of peanut proteins, and laccase catalyzes pyrogallol to link a large number of proteins together, forming a strong and elastic network structure.

[0051] (5) Microstructure of peanut protein gel The microstructure of peanut protein gels was observed using scanning electron microscopy. Peanut protein gels prepared in Examples 1-9 and Comparative Examples 1-7 were cut into 1 mm × 1 mm × 1 mm pieces, fixed overnight in 2.5% glutaraldehyde solution, and then dehydrated sequentially in 50%, 70%, 90%, and 100% (v / v) ethanol, each dehydration lasting 15 min. Afterwards, tert-butanol was used as a replacement treatment, followed by freeze-drying and gold sputtering. The gels were then observed under a scanning electron microscope with an accelerating voltage of 5 kV.

[0052] Depend on Figure 4 The results showed that the gel networks of Comparative Examples 1-7 exhibited numerous sheet-like structures, forming relatively loose voids, indicating that no effective cross-linking was achieved. In contrast, the microstructures of Examples 1-9 were primarily composed of flat structures with a dense network structure. This was due to the combined effect of physical / chemical modification pretreatment and laccase-catalyzed pyrogallol, which enabled peanut protein to form numerous binding bonds, resulting in a uniform gel structure with the help of pyrogallol.

[0053] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a low-allergenicity, high-stability peanut protein gel, characterized in that, Includes the following steps: S1. The peanut protein dispersion was subjected to physical / chemical coupling modification pretreatment; The physical / chemical coupling modification method is as follows: the peanut protein dispersion is first subjected to ultrasonic treatment, dynamic high-pressure microfluidic treatment or microwave treatment, and then subjected to pH shift combined with mild heat treatment. S2. Add pyrogallol-structured polyphenols and laccase to the pretreated peanut protein system to carry out an enzyme-catalyzed oxidative cross-linking reaction. S3. The product of the enzyme-catalyzed oxidative cross-linking reaction is heated to induce gelation, and then cooled to obtain peanut protein gel.

2. The method for preparing the low-allergenicity and high-stability peanut protein gel according to claim 1, characterized in that, In step S1, the mass percentage concentration of the peanut protein dispersion is 5-15%.

3. The method for preparing the low-allergenicity and high-stability peanut protein gel according to claim 1, characterized in that, The ultrasonic treatment has a power of 200-800W and a treatment time of 5-20 min; the dynamic high-pressure microjet treatment has a homogenization pressure of 30-150 MPa and a cycle count of 1-3 times; the microwave treatment has a microwave power of 400-600 W, a temperature of 50-70℃, and a microwave treatment time of 2-6 min.

4. The method for preparing the low-allergenicity and high-stability peanut protein gel according to claim 1, characterized in that, The pH shift combined with mild heat treatment is as follows: the protein is subjected to pH shift treatment, followed by heat treatment, and then the pH of the heat-treated solution is adjusted to neutral; wherein, the pH shift treatment conditions are: pH 9.0-12.0, time 5-30 min; the heat treatment conditions are: temperature 40-80℃, time 30-120 min.

5. The method for preparing the low-allergenicity and high-stability peanut protein gel according to claim 1, characterized in that, In step S2, the amount of the pyrogallol-structured polyphenol added is 0.1-3.0% of the peanut protein content.

6. The method for preparing the low-allergenicity and high-stability peanut protein gel according to claim 1, characterized in that, The pyrogallol-structured polyphenol is one or a combination of two or more of gallocatechin, epigallocatechin, delphinidin, and myricetin.

7. The method for preparing the low-allergenicity and high-stability peanut protein gel according to claim 1, characterized in that, The amount of laccase added is 5-80 U / g protein, and the pH is 5.5-7.

5.

8. The method for preparing the low-allergenicity and high-stability peanut protein gel according to claim 1, characterized in that, The enzyme-catalyzed oxidative crosslinking reaction is carried out at a temperature of 25-55℃ for a reaction time of 1-8 h.

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