A method for improving thermal coagulation performance of vegetable protein

Abstract

The present invention provides a method for processing vegetable protein, comprising the steps of subjecting a solution containing vegetable protein to heat treatment at different temperatures three times, and subjecting the heat-treated solution to isoelectric point precipitation to obtain protein curd. The vegetable protein prepared by the process of the present invention has improved thermal coagulation performance, so that it can replace egg white protein in the preparation of baked goods.

Description

Technical Field

[0001] The invention belongs to the technical field of plant protein processing, and relates to a method for processing protein with improved thermal coagulation performance. Background Art

[0002] Traditional angel food cake is a type of cake product that uses only egg white, flour and sugar as ingredients but does not contain egg yolk or oil. It has a white interior, a uniform and fluffy texture, a sweet but not greasy taste, and a soft and delicious texture. It is a good choice for consumers who prefer low-fat or low-calorie desserts. In addition, as consumers pay more attention to plant protein, using plant protein to replace animal protein in food manufacturing has become a trend in the development of healthy foods. Soy protein, as an important plant protein, is rich in resources, comprehensive in nutrition, and low in price. It has a good application prospect in the baking field to replace egg protein.

[0003] Compared with egg white protein, the foaming property and foam stability of soy protein are far inferior to those of egg white protein, so it is necessary to use certain process means to improve the foaming property of soy protein. Compared with physical modification and chemical modification means, enzymatic modification has mild reaction conditions, controllable results, and is widely used. Patent CN103748207A uses protein or polypeptides generated by protease and glutamine transaminase acting on protein materials as effective ingredients, and can improve the foam stability of beer-like foaming beverages and other compositions. Patent CN101366469B first hydrolyzes soy protein isolate with alkaline protease Alcalase, then ultrafilters to obtain protein peptides with a molecular weight of more than 10kDa, and then cross-links them with glutaminase (TGase). The foaming property and foam stability of the obtained product are comparable to those of egg white protein. Patent CN107242347A uses de-oiled low-temperature soybean meal to extract protein liquid, and uses neutral protease for primary enzymolysis and alkaline protease for secondary enzymolysis to obtain soy protein with improved foaming property.

[0004] However, CWPERNELL (Journal of Food Science, 2002, Vol67, Nr8, 2945-2951) and TRISTAN K.BERRRY (Journal of Food Science, 2009, Vol74, Nr5, 269-277) et al. found in their research on cake batter and angel food cake that when whey protein isolate with good foaming property and foam stability is used to replace egg protein in a certain proportion, the internal pores of angel food cake are coarse, the pore walls are rough, the specific volume is reduced, and the overall acceptance is greatly reduced. In addition, many studies have also found that when the proportion of soy protein replacing egg white protein exceeds 30%, angel food cake will also have the above problems. This is mainly because egg white protein has good thermal coagulation during baking, can quickly coagulate at 62-65°C and form a firm network structure with gelatinized starch to support and wrap bubbles, preventing bubbles from over-expanding or collapsing. Obviously, when other proteins are used to replace egg white protein, in addition to having better foaming properties and foam stability, they must also have similar thermal coagulation properties as egg white protein.

[0005] Although the above patented method improves the foaming ability and foam stability of the soy protein solution at room temperature, it does not involve the improvement of the thermal coagulation of soy protein. Since soy protein does not have the thermal coagulation of egg white protein, the application of its foaming property in baked foods is still relatively limited. The prior art still lacks a soy protein isolate product that can replace egg white protein in a high proportion in practical applications and will not have a negative impact on the overall quality of angel food cakes. Summary of the invention

[0006] In order to solve the problem that the existing soy protein currently lacks the thermal coagulation property of egg white protein, the present invention provides a method for processing plant protein, the method comprising:

[0007] (1) providing a protein solution, contacting the protein solution with a coagulant, and heating the solution;

[0008] (2) adjusting the pH of the heated solution and heating it a second time;

[0009] (3) The step of contacting the second-heated solution with transglutaminase and heating it for a third time.

[0010] In one or more embodiments, the coagulant is one or more of glucono-δ-lactone, calcium sulfate, calcium lactate, calcium chloride, magnesium chloride, and magnesium sulfate.

[0011] In one or more embodiments, the amount of the coagulant is 0.008-0.8 wt ‰ of the dry matter of the protein solution.

[0012] In one or more embodiments, the heating temperature of step (1) in the method is 100-120° C., and the heating time is 30-60 min.

[0013] In one or more embodiments, the heating temperature in step (2) of the method is 70-90° C., and the heating time is 10-30 min.

[0014] In one or more embodiments, the heating temperature in step (3) of the method is 40-60° C., and the heating time is 30-120 min.

[0015] In one or more embodiments, step (2) of the method adjusts the pH to 5.0-6.0.

[0016] In one or more embodiments, the protein solution of step (1) in the method is obtained by mixing a protein-containing raw material and water.

[0017] In one or more embodiments, the protein-containing feedstock in the methods is soybean meal.

[0018] In one or more embodiments, the mixing step further includes a step of adjusting pH.

[0019] In one or more embodiments, the mixing step further comprises a step of adjusting the pH to 7.0-9.0.

[0020] In one or more embodiments, the method further comprises a step of adjusting pH to separate the protein curd after the third heating.

[0021] In one or more embodiments, the third heating further comprises the steps of adjusting the pH to 4.45-4.55 and separating the protein curd.

[0022] In one or more embodiments, the method further comprises the steps of neutralizing, and / or enzymatically hydrolyzing, and / or sterilizing, and / or drying the protein curd.

[0023] In one or more embodiments, the transglutaminase is selected from enzymes produced by microorganisms such as Streptomyces mobara, or recombinant enzymes obtained by gene recombination technology.

[0024] In one or more embodiments, the transglutaminase is added in an amount of 0.01-3 wt %, preferably 0.08-2.4 wt %, based on the dry matter weight of the protein solution.

[0025] In one or more embodiments, the neutralization refers to contacting the protein curd with water to obtain a dispersion, and adjusting the pH of the dispersion to 7-8.

[0026] In one or more embodiments, the enzymatic hydrolysis refers to enzymatic hydrolysis using a neutral protease.

[0027] In one or more embodiments, the temperature of the enzymatic hydrolysis step is 40-60°C; and the time of the enzymatic hydrolysis step is 10-60 min.

[0028] In one or more embodiments, the neutral protease is used in an amount of 0.01-5% by weight based on the weight of the protein curd.

[0029] In one or more embodiments, the neutral protease is selected from papain, bromelain, and neutral protease obtained by microbial fermentation, preferably neutral protease obtained by microbial fermentation, more preferably thermoase GL30 neutral protease from Amano Co., Ltd., Japan.

[0030] In one or more embodiments, the sterilization can be performed by boiling water bath sterilization or high temperature steam sterilization.

[0031] In one or more embodiments, the high temperature steam sterilization is performed using steam above 120° C. for a sterilization time of 10-20 seconds.

[0032] In one or more embodiments, the high temperature steam sterilization is performed using steam at 120-150° C. for 10-20 seconds.

[0033] In one or more embodiments, the drying method may be spray drying or freeze drying.

[0034] A second aspect of the present invention provides a method for improving protein coagulability, the method comprising:

[0035] (1) providing a protein solution, contacting the protein solution with a coagulant, and heating the solution;

[0036] (2) adjusting the pH of the heated solution and heating it a second time;

[0037] (3) The step of contacting the second-heated solution with transglutaminase and heating it for a third time.

[0038] In one or more embodiments, the coagulant is one or more of glucono-δ-lactone, calcium sulfate, calcium lactate, calcium chloride, magnesium chloride, and magnesium sulfate.

[0039] In one or more embodiments, the heating temperature of step (1) in the method is 100-120° C., and the heating time is 30-60 min.

[0040] In one or more embodiments, the heating temperature in step (2) of the method is 70-90° C., and the heating time is 10-30 min.

[0041] In one or more embodiments, the heating temperature in step (3) of the method is 40-60° C., and the heating time is 30-120 min.

[0042] In one or more embodiments, step (2) of the method adjusts the pH to 5.0-6.0.

[0043] In one or more embodiments, the protein solution of step (1) in the method is obtained by mixing a protein-containing raw material and water.

[0044] In one or more embodiments, the protein-containing feedstock in the methods is soybean meal.

[0045] In one or more embodiments, the mixing step further includes a step of adjusting pH.

[0046] In one or more embodiments, the mixing step further comprises a step of adjusting the pH to 7.0-9.0.

[0047] In one or more embodiments, the method further comprises a step of adjusting pH to separate the protein curd after the third heating.

[0048] In one or more embodiments, the third heating further comprises the steps of adjusting the pH to 4.45-4.55 and separating the protein curd.

[0049] In one or more embodiments, the method further comprises the steps of neutralizing, and / or enzymatically hydrolyzing, and / or sterilizing, and / or drying the protein curd.

[0050] In one or more embodiments, the transglutaminase is selected from enzymes produced by microorganisms such as Streptomyces mobara, or recombinant enzymes obtained by gene recombination technology.

[0051] In one or more embodiments, the transglutaminase is added in an amount of 0.01-3 wt %, preferably 0.08-2.4 wt %, based on the dry matter weight of the protein solution.

[0052] In one or more embodiments, the neutralization refers to contacting the protein curd with water to obtain a dispersion, and adjusting the pH of the dispersion to 7-8.

[0053] In one or more embodiments, the enzymatic hydrolysis refers to enzymatic hydrolysis using a neutral protease.

[0054] In one or more embodiments, the temperature of the enzymatic hydrolysis step is 40-60°C; and the time of the enzymatic hydrolysis step is 10-60 min.

[0055] In one or more embodiments, the neutral protease is used in an amount of 0.01-5% by weight based on the weight of the protein curd.

[0056] In one or more embodiments, the neutral protease is selected from papain, bromelain, and neutral protease obtained by microbial fermentation, preferably neutral protease obtained by microbial fermentation, more preferably thermoase GL30 neutral protease from Amano Co., Ltd. of Japan.

[0057] In one or more embodiments, the sterilization can be performed by boiling water bath sterilization or high temperature steam sterilization.

[0058] In one or more embodiments, the high temperature steam sterilization is performed using steam above 120° C. for a sterilization time of 10-20 seconds.

[0059] In one or more embodiments, the high temperature steam sterilization is performed using steam at 120-150° C. for 10-20 seconds.

[0060] In one or more embodiments, the drying method may be spray drying or freeze drying.

[0061] The third aspect of the present invention provides a protein product, which is prepared by the protein processing process of the present invention.

[0062] In one or more embodiments, the protein product has a foaming property of 800%-900%, and / or a foam stability of 70%-80%, and / or a heat setting property of 50%-60% at 65°C, and / or a heat setting property of 75%-85% at 75°C.

[0063] A baked product, comprising protein prepared by the method of the present invention.

[0064] In one or more embodiments, the baked product is angel food cake, chiffon cake, or sponge cake.

[0065] In one or more embodiments, the baked good is angel food cake.

[0066] Compared with the prior art, the present invention has the following advantages:

[0067] (1) The soy protein isolate obtained by the present invention has similar whipping properties and thermal coagulation properties as egg white protein, and can replace egg white protein in a high proportion (40%-60%) in angel food cake, and has similar color, specific volume, texture and taste as angel food cake with 100% egg white protein, thus solving the problem of low soy protein replacement ratio in the prior art and significantly lower cake acceptance than 100% egg white protein.

[0068] (2) The present invention modifies the soy protein isolate during the extraction process. Compared with the prior art of using soy protein isolate as a starting material for enzymatic modification, the present invention avoids secondary processing of the protein product, has high efficiency and low energy consumption. DETAILED DESCRIPTION

[0069] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following general description and definition of the terms and expressions mentioned in the specification and claims are provided. Unless otherwise specified, all technical and scientific terms used herein have the common meanings understood by those skilled in the art for the present invention. In case of conflict, the definitions in this specification shall prevail.

[0070] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0071] Herein, all features such as values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are for simplicity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to have included and specifically disclosed all possible secondary ranges and individual values ​​within the ranges (including integers and fractions). Herein, unless otherwise specified, percentage refers to mass percentage and ratio refers to mass ratio.

[0072] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0073] Herein, unless otherwise specified, the raw materials mentioned herein may be conventional raw materials in the art, and the processes mentioned herein may adopt conventional operation methods in the art, which can be reasonably determined by those skilled in the art based on the contents disclosed herein and the prior art.

[0074] Preparation of initial protein solution

[0075] The protein solution provided by the present invention can be an aqueous solution of any conventional commercially available protein, or can be a solution containing protein obtained by extracting a protein-containing plant material. According to one embodiment of the present invention, the protein solution of the present invention is obtained by extracting a protein-containing plant material. Preferably, the protein solution of the present invention is obtained by extracting soybean meal.

[0076] Soybean meal is a byproduct obtained after soybean oil is extracted from soybeans. It is also called "soybean meal". The soybean meal obtained after soybean oil extraction and defatting is also called "defatted soybean meal", which usually contains 40-55% protein by weight. In the specific embodiment of the present invention, "defatted soybean meal" is used.

[0077] According to one embodiment of the present invention, the weight ratio of defatted soybean meal raw material to water is 1:5 to 1:50, preferably 1:6 to 1:20, more preferably 1:6.5 to 1:10, and most preferably 1:7 to 1:8. The temperature of the water is 25-70°C, preferably 30-60°C, more preferably 40-55°C, and most preferably 48-50°C. The pH value is close to neutral, for example, it can be 7-9. Any alkalinity can be used to adjust the pH value of the mixture of soybean meal and water. For example, the alkaline solution that can be used includes an aqueous solution of sodium hydroxide, potassium hydroxide, and sodium carbonate. Based on the total weight of the aqueous solution, the concentration of the aqueous solution is 0.1-20% by weight, preferably 2-15% by weight, more preferably 5-12% by weight, and more preferably 8-10% by weight. If the expected range is slightly exceeded inadvertently during the pH adjustment process, an acidic reagent can be used for callback, and the acidic reagent can include a conventional organic acid or inorganic acid, such as hydrochloric acid, phosphoric acid, etc. The step of extracting protein is carried out under stirring, and the stirring can be carried out using various stirring devices such as magnetic stirring rods, stirring blades. The duration of stirring is 1 minute to 10 hours, preferably 10 minutes to 5 hours, more preferably 20 minutes to 2 hours, and most preferably 30 minutes to 1 hour. After extraction, centrifugation or filtration can be used to separate the liquid phase containing protein from the solid phase. According to one embodiment of the present invention, centrifuge is used to separate, and the condition of centrifugation is 500-5000g, preferably 1000-3500g, more preferably 2000-3300g. Centrifugation is carried out for 1-20 minutes, preferably 5-10 minutes. Supernatant solution and precipitation are subsequently collected respectively, wherein supernatant solution can be used as protein solution of the present invention.

[0078] Heat treatment of protein solutions

[0079] The protein heat treatment of the present invention refers to the step of heating the protein solution provided by the present invention. According to one embodiment of the present invention, the heat treatment refers to subjecting the protein solution to heat treatment at different temperatures three times, and the heat treatment at different temperatures three times is also referred to as gradient cooling heat treatment in the embodiments of the present invention.

[0080] The first heat treatment of the protein solution refers to the step of adding a coagulant to the protein solution and heating the solution for the first time within the range of 100-120° C. Specifically, the coagulant is one or more of glucono-δ-lactone, calcium sulfate, calcium lactate, calcium chloride, magnesium chloride, and magnesium sulfate.

[0081] After the first heating step, the method further comprises adjusting the pH of the solution for a second heating step, specifically, adjusting the pH of the solution to 5.0-6.0. The second heating step refers to heating the solution at 70-90° C. for 10-30 minutes.

[0082] After the second heating step, the method further includes contacting the second heated solution with transglutaminase and heating it for the third time. The third heating step refers to heating the solution at 40-60° C., and the heating time is 30-120 min.

[0083] The amount of transglutaminase used in the present invention is 0.01-3% by weight, preferably 0.08-2.4% by weight, based on the mass of the protein-containing plant raw material.

[0084] The amount of transglutaminase used in the present invention is 0.01-3% by weight, preferably 0.08-2.4% by weight, based on the mass of the soybean meal.

[0085] The amount of transglutaminase added in the present invention is 0.01-3% by weight, preferably 0.08-2.4% by weight, of the dry matter of the protein solution. The dry matter of the protein solution in the present invention refers to all components remaining after removing water from the protein solution.

[0086] The dry matter weight of the protein solution in the present invention refers to the total weight of all components remaining after removing water from the protein solution.

[0087] The heating method used for heat treatment in the present invention can be any known heating form, including but not limited to water bath heating, oil bath heating, electric heating jacket heating, etc.

[0088] Preparation of protein curd

[0089] The pH of the heat-treated protein solution of the present invention is adjusted to precipitate the protein and obtain precipitated solid protein. The pH value is 4.45-4.55, and the reagent used to adjust the pH value can be the acidic reagent and alkaline reagent used for extracting the protein above. The generated protein precipitate is separated by centrifugation, and the conditions of the centrifugal operation are as described in the above steps.

[0090] Protease digestion

[0091] The protease enzymolysis of the present invention can use any commercially available protease. 0.01%-5% neutral protease (based on dry precipitate mass) is reacted at 40-60° C. for 10-60 min. The neutral protein neutral enzyme is selected from papain, bromelain and neutral protease obtained by microbial fermentation, preferably neutral protease obtained by microbial fermentation, more preferably thermoase GL30 neutral protease of Japan Amano Co., Ltd.

[0092] Sterilization

[0093] The sterilization of the present invention can be performed by boiling water bath sterilization or high temperature steam sterilization. The boiling water bath sterilization or high temperature steam sterilization can be performed at a conventional temperature for a reasonable time, for example, it can be performed by using indirect heating UHT sterilization equipment known in the art, steam direct UHT sterilization equipment and other equipment, the heating temperature can be above 120°C, preferably 120-150°C, preferably 120-145°C, and the sterilization duration is 10-20 seconds.

[0094] Thermal setting

[0095] The thermal coagulation property of the present invention refers to the denaturation and aggregation of dissolved proteins under heat conditions to form insoluble aggregates and precipitate and solidify into solids with a rigid structure. It is different from gelation, which often refers to the formation of a colloid with a three-dimensional network structure after the protein dispersion is heated and cooled.

[0096] The following examples are further elaborations of the present invention, but the contents of the present invention are not limited by the following contents. The embodiments in the present specification are only used to illustrate the present invention, and they do not limit the scope of protection of the present invention. The scope of protection of the present invention is limited only by the claims, and any omissions, substitutions or modifications made by those skilled in the art on the basis of the embodiments disclosed in the present invention will fall within the scope of protection of the present invention.

[0097] The following examples use conventional instruments and equipment in the art. The experimental methods in the following examples where specific conditions are not specified are usually carried out under conventional conditions or under conditions recommended by the manufacturer. The various raw materials used in the following examples are conventional commercial products unless otherwise specified. In the specification of the present invention and the following examples, unless otherwise specified, "%" means weight percentage and "part" means weight part.

[0098] Foamability measurement: Prepare 100 mL of a 5 wt% protein solution, whip it in a whisk at medium speed for 8 min, then pour it into a 1000 mL graduated cylinder to measure the foam volume V after whipping. 0 After standing for 60 minutes, record the volume V of the foam again. 1 .

[0099] Foaming performance calculation formula:

[0100] Foam stability calculation formula:

[0101] Thermal coagulation test: prepare 100 mL of a protein solution with a protein concentration of 5 wt%, adjust the pH to 7.0, and immediately take two samples (10 mL each) after magnetic stirring for 15 minutes, and determine the protein content by the Kjeldahl method; take another 2 samples (10 mL each), place them in a stoppered test tube, heat them in a water bath at 65°C or 75°C for 15 minutes, then quickly cool them to room temperature, centrifuge them at 2000 r / min for 20 minutes, and determine the protein content of the supernatant.

[0102] Thermal coagulation calculation formula:

[0103] Where P 0 —Protein content before heat treatment

[0104] P 1 — Protein content in the supernatant after heat treatment

[0105] Reagent manufacturer:

[0106] Low temperature defatted soybean meal: Yihai Kerry Jinhai Food Industry Co., Ltd.

[0107] Gluco-δ-lactone: Henan Ruiren Bioengineering Co., Ltd.

[0108] Transglutaminase: Dongsheng Biotechnology Co., Ltd.

[0109] Neutral protease Thermoase GL30: Japan Amano Co., Ltd.

[0110] Papain: Pangbo Biotechnology

[0111] Bromelain: Pangbo Bio

[0112] Equipment manufacturer:

[0113] Steam direct UHT sterilization equipment: Japan OKAWARA company

[0114] Spray drying equipment: GEA

[0115] Example 1

[0116] Weigh 200g of low-temperature defatted soybean meal and stir and disperse it in 1400g of 50℃ warm water, adjust the pH to 9, stir for 60min, and then centrifuge at 3000g centrifugal force for 10min to obtain a supernatant; add 0.008wt‰ glucono-δ-lactone (based on the dry matter weight of the solution) to the supernatant, and heat it at 100℃ for 60min; adjust the pH to 5.0, and heat it at 70℃ for 30min; add 0.08wt% transglutaminase (based on the dry matter weight of the solution), and heat it at 40℃ for 120min; adjust the pH to 4.5 with 1N HCl solution, centrifuge to obtain a curd precipitate; disperse and dissolve the curd precipitate with 10 times the mass of deionized water, adjust the pH to 7.5 with 10% concentration of NaOH solution, and then shear and disperse it at 6000rpm with a shearing machine for 3min; add 0.2% neutral protease Thermoase GL30 (based on dry precipitate mass) was reacted at 50°C for 30 min; finally, it was sterilized in a boiling water bath for 5 min and spray-dried (inlet temperature 185°C, outlet temperature 85°C) to obtain soy protein isolate.

[0117] Comparative Example 1

[0118] The experimental conditions were the same as those of comparative example 1, except that a constant temperature of 100°C was used instead of a gradient cooling heat treatment.

[0119] Comparative Example 2

[0120] The experimental conditions were the same as those of comparative example 1, except that a constant temperature of 40°C was used instead of a gradient cooling heat treatment.

[0121] Comparative Example 3

[0122] The experimental conditions were the same as those of Comparative Example 1, except that glucono-δ-lactone was not added during the gradient cooling heat treatment.

[0123] Comparative Example 4

[0124] The experimental conditions were the same as those of Comparative Example 1, except that the pH value was not adjusted during the gradient cooling heat treatment.

[0125] Comparative Example 5

[0126] The experimental conditions were the same as those of Comparative Example 1, except that no transglutaminase was used during the gradient cooling heat treatment.

[0127] Comparative Example 6

[0128] The experimental conditions were the same as those of Comparative Example 1, except that the temperature was not heated at 100°C for 60 min.

[0129] Comparative Example 7

[0130] The experimental conditions were the same as those of Comparative Example 1, except that the heating was not performed at 70°C for 30 min.

[0131] Comparative Example 8

[0132] The experimental conditions were the same as those of Comparative Example 1, except that the heating was not performed at 40°C for 120 min.

[0133]

[0134]

[0135] Application Examples

[0136] Angel Cake Preparation: Pour the egg white solution into a whisk and beat at medium speed for 6 minutes, then add the powdered sugar three times every 60 seconds, continue to beat until the foam can stand up, add the sifted low-gluten flour and salt, stir at low speed until the batter is evenly mixed, finally pour it into the mold and bake in the oven (upper heat 180℃, lower heat 160℃, time 30 minutes). After the time is up, take it out and let it cool at room temperature, then demould it. The specific formula is as follows:

[0137]

[0138]

[0139] Sensory evaluation: A sensory evaluation team consisting of 10 people

[0140] Color: 7-9 points, the core color is pure white; 4-6 points, the core color is slightly yellow; 1-3 points, the core color is light yellow.

[0141] Specific volume: 7-9 points, no collapse, the volume is close to the blank; 4-6 points, no collapse, the volume is smaller than the blank; 1-3 points, collapse.

[0142] Texture: 7-9 points, the internal pores are uniform and fine, close to the blank; 4-6 points, the internal pores are coarse, slightly worse than the blank; 1-3 points, the internal pores are rough, the pore walls are thick, obviously worse than the blank.

[0143] Taste: 7-9 points, delicate and soft taste; 4-6 points, soft taste but slightly chewy; 1-3 points, hard taste and strong chewiness.

[0144] Color specific volume Texture Taste blank 9 9 9 9 Example 1 - 40% replacement 8 9 8 8 Comparative Example 1-40% replacement 6 1 3 3 Comparative Example 2-40% replacement 6 3 4 3 Comparative Example 3-40% replacement 6 3 4 3 Comparative Example 4-40% replacement 6 3 4 3 Comparative Example 5-40% replacement 6 3 4 3 Comparative Example 6-40% replacement 6 3 4 3 Comparative Example 7-40% replacement 6 3 4 3 Comparative Example 8-40% replacement 6 3 4 3

[0145] Example 2

[0146] 200 g of low-temperature defatted soybean meal was weighed and dispersed in 1400 g of 50° C. warm water, the pH was adjusted to 9, the mixture was stirred for 60 min, and then centrifuged at 3000 g for 10 min to obtain a supernatant; 0.08 wt ‰ glucono-δ-lactone (based on the dry matter weight of the solution) was added to the supernatant, and the mixture was heated at 120° C. for 30 min; the pH was adjusted to 6.0, and the mixture was heated at 90° C. for 10 min; 2.4% transglutaminase (based on the dry matter weight of the solution) was added, and the mixture was heated at 60° C. for 30 min; 1N The pH value was adjusted to 4.5 with HCl solution, and the mixture was centrifuged to obtain a curd precipitate; 8 times the mass of deionized water was used to disperse and dissolve the curd precipitate, and the pH value was adjusted to 8 with a 10% concentration of NaOH solution, and then the curd precipitate was sheared and dispersed at 8000 rpm for 3 minutes with a shearing machine; 0.01% of papain (based on the dry precipitate mass) was added, and the mixture was reacted at 40°C for 60 minutes; finally, the mixture was sterilized with high-temperature steam at 120°C for 20 seconds, and spray-dried (inlet temperature 185°C, outlet temperature 85°C) to obtain soy protein isolate.

[0147] Example 3

[0148] Weigh 200 g of low-temperature defatted soybean meal and stir and disperse it in 1400 g of 50° C. warm water, adjust the pH to 9, stir for 60 minutes, and then centrifuge at 3000 g for 10 minutes to obtain a supernatant; add 0.8‰ glucono-δ-lactone (based on the dry matter weight of the solution) to the supernatant, and heat it at 110° C. for 45 minutes; adjust the pH to 5.5, and heat it at 80° C. for 20 minutes; add 0.8% transglutaminase (based on the dry matter weight of the solution), and heat it at 50° C. for 60 minutes; use 1N The pH value was adjusted to 4.5 with HCl solution, and the mixture was centrifuged to obtain a curd precipitate; 8 times the mass of deionized water was used to disperse and dissolve the curd precipitate, and the pH value was adjusted to 8 with a 10% concentration of NaOH solution, and then the curd precipitate was sheared and dispersed at 8000 rpm for 3 minutes with a shearing machine; 1% of bromelain (based on the dry precipitate mass) was added, and the mixture was reacted at 60° C. for 30 minutes; finally, the mixture was sterilized with high-temperature steam at 140° C. for 15 seconds, and spray-dried (inlet temperature 185° C., outlet temperature 85° C.) to obtain soy protein isolate.

[0149] Example 4

[0150] Weigh 200 g of low-temperature defatted soybean meal and stir and disperse it in 1400 g of 50° C. warm water, adjust the pH to 9, stir for 60 minutes, and then centrifuge at 3000 g for 10 minutes to obtain a supernatant; add 0.1‰ calcium chloride (based on the dry matter weight of the solution) to the supernatant, and heat it at 115° C. for 60 minutes; adjust the pH to 5, and heat it at 70° C. for 30 minutes; add 1% transglutaminase (based on the dry matter weight of the solution), and heat it at 40° C. for 120 minutes; use 1N The pH value was adjusted to 4.55 with HCl solution, and the mixture was centrifuged to obtain a curd precipitate; 8 times the mass of deionized water was used to disperse and dissolve the curd precipitate, and the pH value was adjusted to 8 with a 10% concentration of NaOH solution, and then the curd precipitate was sheared and dispersed at 8000 rpm for 3 minutes with a shearing machine; 1% of bromelain (based on the dry precipitate mass) was added, and the mixture was reacted at 60° C. for 30 minutes; finally, the mixture was sterilized with high-temperature steam at 140° C. for 15 seconds, and spray-dried (inlet temperature 185° C., outlet temperature 85° C.) to obtain soy protein isolate.

[0151]

[0152]

[0153] Application Examples

[0154] Angel Cake Preparation: Pour the egg white solution into a whisk and beat at medium speed for 6 minutes, then add the powdered sugar three times every 60 seconds, continue to beat until the foam can stand up, add the sifted low-gluten flour and salt, stir at low speed until the batter is evenly mixed, finally pour it into the mold and bake in the oven (upper heat 180℃, lower heat 160℃, time 30 minutes). After the time is up, take it out and let it cool at room temperature, then demould it. The specific formula is as follows:

[0155]

[0156]

[0157] Sensory evaluation: A sensory evaluation team consisting of 10 people

[0158] Color: 7-9 points, the core color is pure white; 4-6 points, the core color is slightly yellow; 1-3 points, the core color is light yellow.

[0159] Specific volume: 7-9 points, no collapse, the volume is close to the blank; 4-6 points, no collapse, the volume is smaller than the blank; 1-3 points, collapse.

[0160] Texture: 7-9 points, the internal pores are uniform and fine, close to the blank; 4-6 points, the internal pores are coarse, slightly worse than the blank; 1-3 points, the internal pores are rough, the pore walls are thick, obviously worse than the blank.

[0161] Taste: 7-9 points, delicate and soft taste; 4-6 points, soft taste but slightly chewy; 1-3 points, hard taste and strong chewiness.

[0162] Color specific volume Texture Taste Example 2 - 40% replacement 8 9 8 8 Example 2 - 50% replacement 8 8 8 8 Example 2 - 60% replacement 8 8 8 7 Example 3 - 40% replacement 8 9 8 8 Example 3 - 50% replacement 8 8 8 7 Example 3 - 60% replacement 8 8 8 7 Example 4 - 40% replacement 8 8 8 7 Example 4 - 50% replacement 8 9 8 8 Example 4 - 60% replacement 8 8 8 7

Claims

1. A method for processing vegetable protein, It is characterized in that The method comprises: (1) providing a soy protein solution, contacting the protein solution with a coagulant, and heating the solution, wherein the heating temperature is 100-120° C. and the heating time is 30-60 min; (2) adjusting the pH of the heated solution to 5.0-6.0 and heating it for a second time, wherein the heating temperature is 70-90° C. and the heating time is 10-30 min; (3) contacting the second heated solution with transglutaminase and heating it for a third time, wherein the heating temperature is 40-60° C. and the heating time is 30-120 min; After the third heating, the step of adjusting pH to separate protein curd is also included; The method further comprises the steps of neutralizing, enzymolysis, sterilizing, and drying the protein curd; the amount of the coagulant is 0.008-0.8 weight ‰ of the dry matter of the protein solution; and the amount of the transglutaminase added is 0.01-3 weight % of the dry matter of the protein solution.

2. The method for processing vegetable protein according to claim 1, It is characterized in that The method is used to improve the thermal coagulation property of protein.

3. The method according to claim 1 or 2, It is characterized in that The coagulant is one or more of glucono-δ-lactone, calcium sulfate, calcium lactate, calcium chloride, magnesium chloride, and magnesium sulfate.

4. The method according to claim 1 or 2, It is characterized in that The protein solution in step (1) of the method is obtained by mixing a protein-containing raw material and water.

5. The method according to claim 4, It is characterized in that The step of adjusting pH is further included after the mixing step, and / or the protein-containing raw material is soybean meal.

6. The method according to claim 5, It is characterized in that The step of adjusting the pH to 7.0-9.0 is also included after the mixing step.

7. The method according to claim 1, It is characterized in that The pH was adjusted to 4.45-4.

55.

8. A plant protein, It is characterized in that The plant protein is prepared by the method according to any one of claims 1 to 7.

9. A baked product, comprising the plant protein prepared by the method according to any one of claims 1 to 7 or the plant protein according to claim 8.

10. The baked product according to claim 9, It is characterized in that The baked product is selected from angel cake, chiffon cake and sponge cake.

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