阅读说明：本技术 一种增强主食营养成分的杂豆处理工艺 (Mixed bean treatment process for enhancing nutritional ingredients of staple food ) 是由 刘井山 于 2021-08-16 设计创作，主要内容包括：本发明涉及一种增强主食营养成分的杂豆处理工艺,属于杂豆处理技术领域,第一步、将杂豆清洗碱浸,加水磨浆过筛,调节pH值为6,静置12h后,离心取沉淀,将沉淀于乙醚溶液中搅拌,抽滤,收集滤饼,得到粗提物；第二步、将粗提物和水搅拌混合,加入乙醇,离心收集沉淀,得到杂豆蛋白；第三步、将杂豆蛋白和水超声分散,加入三偏磷酸钠,调节pH值至9,于55℃下水浴中搅拌反应2h,调节pH值至7-8,透析后冷冻干燥,得到改性蛋白；第四步、将改性蛋白和改性壳聚糖混合均匀,得到增强主食营养成分的杂豆提取物；本发明对杂豆蛋白进行改性,提高其水溶性,增加其与主食面粉的相容性,添加改性壳聚糖,提高其防腐防霉效果。(The invention relates to a miscellaneous bean processing technology for enhancing the nutrient content of staple food, belonging to the technical field of miscellaneous bean processing, comprising the following steps of firstly, cleaning and alkaline leaching miscellaneous beans, adding water, grinding into slurry, sieving, adjusting the pH value to 6, standing for 12 hours, centrifuging, taking precipitate, stirring the precipitate in an ether solution, carrying out suction filtration, and collecting filter cakes to obtain a crude extract; secondly, stirring and mixing the crude extract with water, adding ethanol, centrifuging and collecting precipitates to obtain the hybrid bean protein; thirdly, ultrasonically dispersing the hybrid bean protein and water, adding sodium trimetaphosphate, adjusting the pH value to 9, stirring and reacting in a water bath at 55 ℃ for 2 hours, adjusting the pH value to 7-8, dialyzing, and freeze-drying to obtain modified protein; fourthly, uniformly mixing the modified protein and the modified chitosan to obtain a mixed bean extract for enhancing the nutrient content of the staple food; the invention modifies the mixed bean protein, improves the water solubility of the mixed bean protein, increases the compatibility of the mixed bean protein and the staple food flour, and improves the antiseptic and mildew-proof effects of the mixed bean protein by adding the modified chitosan.)

1. A mixed bean processing technology for enhancing the nutrient content of staple food is characterized by comprising the following steps:

cleaning mixed beans, soaking the washed mixed beans in a sodium hydroxide solution for 17 hours, adding water, grinding the mixed beans into milk, sieving the ground milk to collect soybean milk, adding acetic acid into the soybean milk to adjust the pH value to 6, standing the soybean milk for 12 hours, centrifuging the soybean milk for 10 minutes, taking a precipitate, stirring the precipitate in an ether solution for 20 minutes, performing suction filtration, and collecting a filter cake to obtain a crude extract;

secondly, adding the crude extract and water into a reactor, mixing for 20min, adding ethanol, stirring, centrifuging, and collecting precipitate to obtain the hybrid soybean protein;

adding the hybrid bean protein and water into a reaction container, performing ultrasonic dispersion for 20min, adding sodium trimetaphosphate, adjusting the pH value to 9 by using a sodium hydroxide solution, performing stirring reaction in a water bath at 55 ℃ for 2h, adding a hydrochloric acid solution to adjust the pH value to 7-8, and finally dialyzing in distilled water for 72h, and performing freeze drying at-45 ℃ for 24h to obtain modified protein;

fourthly, mixing the modified protein and the modified chitosan according to the mass ratio of 100: 0.8-1.5, and mixing uniformly to obtain the mixed bean extract for enhancing the nutrient content of the staple food.

2. The processing technology of the mixed beans for enhancing the nutrient content of the staple food as claimed in claim 1, wherein the ratio of the mixed bean protein, the water and the sodium trimetaphosphate in the third step is 5.8-6.3 g: 15-18 mL: 0.5-1.1 g.

3. The mixed bean processing technology for enhancing the nutrient content of the main food as claimed in claim 1, wherein the modified chitosan is prepared by the following steps:

step 1, stirring and mixing eugenol, absolute ethyl alcohol and formic acid, then dropwise adding a hydrogen peroxide solution, heating to 60-65 ℃, stirring for reacting for 2-4h, adding sodium hydroxide, stirring, adjusting the pH value to 2, filtering, washing a filter cake, and drying to obtain an intermediate product 1;

step 2, adding the intermediate product 1 into dimethyl sulfoxide, dropwise adding N, N-dimethylformamide and thionyl chloride, refluxing, stirring, reacting for 3 hours, washing, extracting and performing rotary evaporation to obtain an intermediate product 2;

step 3, dissolving chitosan in an acetic acid solution, adding methanol, heating to 60 ℃ after stirring, dropwise adding a mixed solution a of benzaldehyde and methanol, carrying out heat preservation reaction for 1-2h, cooling, adjusting the pH value to 7.0, carrying out suction filtration after stirring, carrying out Soxhlet extraction on a filter cake, washing and drying to obtain an intermediate product 3;

step 4, adding the intermediate product 2 into DMF, stirring for 10-15min, then dropwise adding a DMF solution of the intermediate product 3, adding pyridine, stirring for 1-2h, adding acetone with the volume 3 times that of the reactant, performing suction filtration, washing precipitates, and drying to obtain an intermediate product 4;

and 5, mixing the hydrochloric acid solution with ethanol, adding the intermediate product 4 after stirring, adjusting the pH value to 7 after stirring at room temperature for 12 hours, washing, performing suction filtration, drying, dialyzing for 12 hours, precipitating with acetone, performing suction filtration, and drying to obtain the modified chitosan.

4. The miscellaneous bean processing technology for enhancing the nutritional ingredients of the main food according to claim 3, wherein the dosage ratio of the eugenol, the absolute ethyl alcohol, the formic acid, the hydrogen peroxide solution and the sodium hydroxide in the step 1 is 6.4 mmol: 20-40 mL: 32.7-38.4 mmol: 8.5-9.1 mL: 1.1-2.3 g.

5. The processing technology of the mixed beans for enhancing the nutrient content of the main food according to claim 3, wherein the dosage ratio of the intermediate product 1, the dimethyl sulfoxide, the N, N-dimethylformamide and the thionyl chloride in the step 2 is 3-5 g: 25.2-28.7 mL: 1-3 mL: 3.3-4.6 mL.

6. The mixed bean processing technology for enhancing the nutrient content of the main food as claimed in claim 3, wherein the mixed liquor a in the step 3 is prepared by mixing benzaldehyde and methanol according to a volume ratio of 1: 1 are mixed.

7. The process of claim 3, wherein the DMF solution of intermediate 3 in step 4 is prepared from intermediate 3 and DMF in a ratio of 1 g: 8.5-9.1 mL.

8. The mixed bean processing technology for enhancing the nutrient content of the main food as claimed in claim 3, wherein the dosage ratio of the hydrochloric acid solution, the ethanol and the intermediate product 4 in the step 5 is 10 mL: 38-44 mL: 2.2-2.7 g.

Technical Field

The invention belongs to the technical field of mixed bean treatment, and particularly relates to a mixed bean treatment process for enhancing nutritional ingredients of a staple food.

Background

The beans have been considered as good sources of vegetable proteins, vitamins (thiamine and niacin, etc.), mineral elements (P, K, Ca, Mg, etc.) and dietary fibers. Research shows that the phaseolin has the efficacy of reducing plasma low-density lipoprotein, the slowly digestible starch and the resistance content of the phaseolin are higher, the digestion speed of the starch is lower than that of cereal starch and rhizome starch, and the rapid change of postprandial blood sugar and insulin cannot be caused. The hybrid beans and the grains have complementation in amino acid content, and the combination of the grains and the beans can effectively solve the problem that the single raw material limits insufficient amino acid and improve the protein absorption rate.

The existing mixed bean processing technology is generally to grind mixed beans into powder to be mixed with other grains, and the pure mixing technology influences the taste of the composite food and cannot enrich and extract beneficial substances in the mixed beans, so that the technical problem to be solved at present is to provide the mixed bean processing technology for enhancing the nutrient content of the staple food.

Disclosure of Invention

The invention aims to provide a mixed bean processing technology for enhancing the nutrient content of staple food, which is used for solving the problems in the background technology.

The purpose of the invention can be realized by the following technical scheme:

a mixed bean processing technology for enhancing the nutrient content of staple food comprises the following steps:

cleaning mixed beans, soaking the cleaned mixed beans in a sodium hydroxide solution with the concentration of 0.05mol/L for 17 hours, adding water, grinding the mixed beans into milk, sieving the milk with a 150-mesh sieve, collecting the soybean milk, adding acetic acid into the soybean milk to adjust the pH value to be 6, standing the soybean milk for 12 hours, centrifuging the soybean milk at the rotating speed of 1500r/min for 10 minutes, taking a precipitate, stirring the precipitate in an ether solution for 20 minutes, performing suction filtration, and collecting a filter cake to obtain a crude extract;

secondly, adding the crude extract and water into a reactor, stirring and mixing for 20min, adding ethanol, stirring for 20min at the rotation speed of 167-;

adding the phaseolus vulgaris protein and water into a reaction container, ultrasonically dispersing for 20min at the frequency of 40-50kHz, then adding sodium trimetaphosphate, adjusting the pH value to 9 by using a sodium hydroxide solution with the concentration of 1mol/L, stirring and reacting for 2h in a water bath at the temperature of 55 ℃, then adding a hydrochloric acid solution with the concentration of 1mol/L to adjust the pH value to 7-8, finally dialyzing for 72h in distilled water, replacing the distilled water every 6h, and freeze-drying for 24h at the temperature of-45 ℃ to obtain modified protein;

fourthly, mixing the modified protein and the modified chitosan according to the mass ratio of 100: 0.8-1.5, and mixing uniformly to obtain the mixed bean extract for enhancing the nutrient content of the staple food.

Further, the mixed beans in the first step are one or more of red beans, mung beans, hyacinth beans, kidney beans and chickpeas which are mixed according to any proportion.

Furthermore, in the third step, the dosage ratio of the hybrid bean protein to the water to the sodium trimetaphosphate is 5.8-6.3 g: 15-18 mL: 0.5-1.1 g.

Further, the modified chitosan is prepared by the following steps:

step 1, adding eugenol, absolute ethyl alcohol and formic acid into a three-neck flask, stirring for 5min at the rotating speed of 60-80r/min, dropwise adding a hydrogen peroxide solution with the mass fraction of 30%, heating to 60-65 ℃ after dropwise adding, stirring for reacting for 2-4h, adding sodium hydroxide into a reaction solution after the reaction is finished, stirring for 10min, adding a hydrochloric acid solution with the mass fraction of 37% to adjust the pH value to 2, separating out a white solid, filtering, washing a filter cake with distilled water until a washing solution is neutral, and drying at the temperature of 60 ℃ to constant weight to obtain an intermediate product 1;

step 2, adding the intermediate product 1 and dimethyl sulfoxide into a three-neck flask, stirring for 3min, dropwise adding N, N-dimethylformamide and thionyl chloride into the three-neck flask, heating to 90 ℃ after dropwise adding, refluxing, stirring and reacting for 3h, washing with deionized water after reaction, extracting with ethyl acetate, and removing the ethyl acetate by rotary evaporation to obtain an intermediate product 2;

step 3, dissolving chitosan in an acetic acid solution with the mass fraction of 1%, adding methanol, stirring for 5min, heating to 60 ℃, dropwise adding a mixed solution a of benzaldehyde and methanol, after dropwise adding, carrying out heat preservation reaction for 1-2h, after the reaction is finished, cooling, dropwise adding a sodium hydroxide solution with the mass fraction of 5% to adjust the pH value to 7.0, stirring for 30min, carrying out suction filtration, carrying out soxhlet extraction on a filter cake for 12h by using absolute ethyl alcohol, washing to be neutral, and carrying out vacuum drying at 60 ℃ to constant weight to obtain an intermediate product 3;

step 4, adding the intermediate product 2 and DMF into a three-neck flask, stirring for 10-15min, then dropwise adding a DMF solution of the intermediate product 3, stirring while dropwise adding, adding pyridine after dropwise adding, stirring for 1-2h, adding acetone with the volume 3 times that of the reactant after reaction to precipitate the product, performing suction filtration, washing the precipitate, and drying for 24h at 60 ℃ to obtain an intermediate product 4;

and 5, adding hydrochloric acid solution with the concentration of 0.25mol/L and ethanol into a round-bottom flask, stirring for 3min, adding the intermediate product 4, stirring for 12h at room temperature, adding sodium carbonate solution with the mass fraction of 10%, adjusting the pH value to 7, washing for 3-5 times by using acetone, carrying out suction filtration, carrying out vacuum drying at 60 ℃, dialyzing for 12h in a dialysis bag after drying, precipitating by using acetone, carrying out suction filtration, and drying to obtain the modified chitosan.

Further, the dosage ratio of the eugenol, the absolute ethyl alcohol, the formic acid, the hydrogen peroxide solution and the sodium hydroxide in the step 1 is 6.4 mmol: 20-40 mL: 32.7-38.4 mmol: 8.5-9.1 mL: 1.1-2.3 g.

Further, the dosage ratio of the intermediate product 1, the dimethyl sulfoxide, the N, N-dimethylformamide and the thionyl chloride in the step 2 is 3-5 g: 25.2-28.7 mL: 1-3 mL: 3.3-4.6 mL.

Further, in the step 3, the dosage ratio of the chitosan, the acetic acid solution, the methanol and the solution a is 2.5-2.8 g: 15-17 mL: 2mL of: 15.8-16.3mL, wherein the mixed solution a is prepared from benzaldehyde and methanol according to the volume ratio of 1: 1 are mixed.

Further, the ratio of the amount of intermediate 2, DMF, the DMF solution of intermediate 3 and pyridine in step 4 was 50 mmol: 30-45 mL: 25.8-26.4 mL: 0.8-1.1g, wherein the DMF solution of intermediate 3 is prepared from intermediate 3 and DMF according to a weight ratio of 1 g: 8.5-9.1 mL.

Further, the dosage ratio of the hydrochloric acid solution, the ethanol and the intermediate product 4 in the step 5 is 10 mL: 38-44 mL: 2.2-2.7 g.

The invention has the beneficial effects that:

the invention obtains the hybrid bean protein after the alkaline leaching and the pulp grinding extraction of the hybrid bean, then the phosphate modification is carried out to the hybrid bean protein, the phosphate can form ester with the hydroxyl on the hybrid bean protein molecule, and the phosphate group is along with the proteinThe method comprises the steps of firstly oxidizing eugenol in a formic acid and hydrogen peroxide solution to obtain an intermediate product 1 with a benzene ring connected with carboxyl, further performing substitution reaction on the intermediate product 1 and thionyl chloride to obtain an intermediate product 2 with an acyl chloride structure, and further performing-NH reaction on chitosan₂Performing addition reaction with-CHO of benzaldehyde to protect amino to obtain intermediate product 3, performing substitution reaction between Cl of intermediate product 2 and-OH of intermediate product 3 to obtain intermediate product 4, and deprotecting intermediate product 4 in ethanol solution of hydrochloric acid to release amino to obtain chitosan containing amino and grafted intermediate product 2, i.e. modified chitosan₂The modified chitosan with antibacterial advantages is obtained by modifying the modified chitosan by taking the two as raw materials through chemical reaction, the modified chitosan can effectively prevent the modified protein from mildewing and deteriorating and the like by adding the modified chitosan, the quality guarantee period of the modified protein is prolonged, and the hybrid bean protein is modified, the water solubility of the hybrid bean protein is improved, the compatibility of the hybrid bean protein and the staple food flour is improved, and the antiseptic and mildew-proof effects of the hybrid bean protein are improved by adding the modified chitosan.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to 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.

Example 1

The modified chitosan is prepared by the following steps:

step 1, adding 6.4mmol of eugenol, 20mL of anhydrous ethanol and 32.7mmol of formic acid into a three-neck flask, stirring for 5min at a rotation speed of 60r/min, dropwise adding 8.5mL of a hydrogen peroxide solution with a mass fraction of 30%, heating to 60 ℃ after dropwise adding, stirring for reacting for 2h, adding 1.1g of sodium hydroxide into a reaction solution after the reaction is finished, stirring for 10min, adding a hydrochloric acid solution with a mass fraction of 37% to adjust the pH value to be 2, separating out a white solid, filtering, washing a filter cake with distilled water until a washing solution is neutral, and drying at a temperature of 60 ℃ to constant weight to obtain an intermediate product 1;

step 2, adding 3g of intermediate product 1 and 25.2mL of dimethyl sulfoxide into a three-neck flask, stirring for 3min, dropwise adding 1mL of N, N-dimethylformamide and 3.3mL of thionyl chloride into the three-neck flask, after dropwise adding, heating to 90 ℃, refluxing and stirring for reaction for 3h, after the reaction is finished, washing with deionized water, extracting with ethyl acetate, and performing rotary evaporation to remove the ethyl acetate to obtain an intermediate product 2;

step 3, dissolving 2.5g of chitosan in 15mL of acetic acid solution with the mass fraction of 1%, adding 2mL of methanol, stirring for 5min, heating to 60 ℃, dropwise adding 15.8mL of mixed solution a of benzaldehyde and methanol, after dropwise adding, preserving heat, reacting for 1h, after the reaction, cooling, dropwise adding sodium hydroxide solution with the mass fraction of 5% to adjust the pH value to 7.0, stirring for 30min, performing suction filtration, soxhlet extracting a filter cake with absolute ethyl alcohol for 12h, washing to be neutral, and performing vacuum drying at 60 ℃ to constant weight to obtain an intermediate product 3;

step 4, adding 50mmol of intermediate product 2 and 30mL of DMF into a three-neck flask, stirring for 10min, dropwise adding 25.8mL of DMF solution of intermediate product 3, stirring while dropwise adding, adding 0.8g of pyridine after dropwise adding, stirring for 1h, adding acetone with the volume 3 times that of the reactant after reaction to precipitate the product, performing suction filtration, washing the precipitate, and drying at 60 ℃ for 24h to obtain intermediate product 4; wherein the DMF solution of intermediate 3 is prepared from intermediate 3 and DMF according to a weight ratio of 1 g: 8.5mL of the mixture;

and 5, adding 0.25mol/L hydrochloric acid solution with the concentration of 10mL and 38mL ethanol into a round-bottom flask, stirring for 3min, adding 2.2g of the intermediate product 4, stirring for 12h at room temperature, adding 10 mass percent sodium carbonate solution to adjust the pH value to 7, washing for 3 times by using acetone, carrying out suction filtration, carrying out vacuum drying at 60 ℃, dialyzing for 12h in a dialysis bag after drying, precipitating by using acetone, carrying out suction filtration, and drying to obtain the modified chitosan.

Example 2

The modified chitosan is prepared by the following steps:

step 1, adding 6.4mmol of eugenol, 30mL of anhydrous ethanol and 33.2mmol of formic acid into a three-neck flask, stirring for 5min at the rotation speed of 70r/min, dropwise adding 8.8mL of hydrogen peroxide solution with the mass fraction of 30%, heating to 62 ℃ after dropwise adding, stirring for reacting for 3h, adding 1.8g of sodium hydroxide into the reaction solution after the reaction is finished, stirring for 10min, adding hydrochloric acid solution with the mass fraction of 37% to adjust the pH value to be 2, separating out white solid, filtering, washing a filter cake with distilled water until the washing solution is neutral, and drying at the temperature of 60 ℃ to constant weight to obtain an intermediate product 1;

step 2, adding 4g of intermediate product 1 and 26.7mL of dimethyl sulfoxide into a three-neck flask, stirring for 3min, dropwise adding 2mL of N, N-dimethylformamide and 3.9mL of thionyl chloride into the three-neck flask, after dropwise adding, heating to 90 ℃, refluxing and stirring for reaction for 3h, after the reaction is finished, washing with deionized water, extracting with ethyl acetate, and performing rotary evaporation to remove the ethyl acetate to obtain an intermediate product 2;

step 3, dissolving 2.6g of chitosan in 16mL of acetic acid solution with the mass fraction of 1%, adding 2mL of methanol, stirring for 5min, heating to 60 ℃, dropwise adding 16.1mL of mixed solution a of benzaldehyde and methanol, after dropwise adding, carrying out heat preservation reaction for 1.5h, after the reaction is finished, cooling, dropwise adding sodium hydroxide solution with the mass fraction of 5% to adjust the pH value to 7.0, stirring for 30min, carrying out suction filtration, soxhlet extracting a filter cake with absolute ethyl alcohol for 12h, washing to be neutral, and carrying out vacuum drying at 60 ℃ to constant weight to obtain an intermediate product 3;

step 4, adding 50mmol of intermediate product 2 and 38mL of DMF into a three-neck flask, stirring for 12min, dropwise adding 26.1mL of DMF solution of intermediate product 3, stirring while dropwise adding, adding 1.0g of pyridine after dropwise adding, stirring for 1.5h, adding acetone with the volume 3 times that of reactants after reaction to precipitate the product, performing suction filtration, washing the precipitate, and drying at 60 ℃ for 24h to obtain intermediate product 4; wherein the DMF solution of intermediate 3 is prepared from intermediate 3 and DMF according to a weight ratio of 1 g: 8.9mL of the mixture;

and 5, adding 0.25mol/L hydrochloric acid solution with the concentration of 10mL and 40mL of ethanol into a round-bottom flask, stirring for 3min, adding 2.5g of the intermediate product 4, stirring for 12h at room temperature, adding 10 mass percent sodium carbonate solution to adjust the pH value to 7, washing for 4 times by using acetone, carrying out suction filtration, carrying out vacuum drying at 60 ℃, dialyzing for 12h in a dialysis bag after drying, precipitating by using acetone, carrying out suction filtration, and drying to obtain the modified chitosan.

Example 3

The modified chitosan is prepared by the following steps:

step 1, adding 6.4mmol of eugenol, 40mL of anhydrous ethanol and 38.4mmol of formic acid into a three-neck flask, stirring for 5min at a rotating speed of 80r/min, dropwise adding 9.1mL of a hydrogen peroxide solution with a mass fraction of 30%, heating to 65 ℃ after dropwise adding, stirring for reacting for 4h, adding 2.3g of sodium hydroxide into a reaction solution after the reaction is finished, stirring for 10min, adding a hydrochloric acid solution with a mass fraction of 37% to adjust the pH value to be 2, separating out a white solid, filtering, washing a filter cake with distilled water until a washing solution is neutral, and drying at a temperature of 60 ℃ to constant weight to obtain an intermediate product 1;

step 2, adding 5g of the intermediate product 1 and 28.7mL of dimethyl sulfoxide into a three-neck flask, stirring for 3min, dropwise adding 3mL of N, N-dimethylformamide and 4.6mL of thionyl chloride into the three-neck flask, heating to 90 ℃ after dropwise adding, refluxing and stirring for reaction for 3h, washing with deionized water after the reaction is finished, extracting with ethyl acetate, and removing the ethyl acetate by rotary evaporation to obtain an intermediate product 2;

step 3, dissolving 2.8g of chitosan in 17mL of acetic acid solution with the mass fraction of 1%, adding 2mL of methanol, stirring for 5min, heating to 60 ℃, dropwise adding 16.3mL of mixed solution a of benzaldehyde and methanol, after dropwise adding, preserving heat, reacting for 2h, after the reaction, cooling, dropwise adding sodium hydroxide solution with the mass fraction of 5% to adjust the pH value to 7.0, stirring for 30min, performing suction filtration, soxhlet extracting a filter cake with absolute ethyl alcohol for 12h, washing to be neutral, and performing vacuum drying at 60 ℃ to constant weight to obtain an intermediate product 3;

step 4, adding 50mmol of intermediate product 2 and 45mL of DMF into a three-neck flask, stirring for 15min, dropwise adding 26.4mL of DMF solution of intermediate product 3, stirring while dropwise adding, after dropwise adding, adding 1.1g of pyridine, stirring for 2h, after reaction, adding acetone with the volume 3 times that of the reactant to precipitate the product, performing suction filtration, washing the precipitate, and drying at 60 ℃ for 24h to obtain intermediate product 4; wherein the DMF solution of intermediate 3 is prepared from intermediate 3 and DMF according to a weight ratio of 1 g: 9.1mL of the mixture;

and 5, adding 0.25mol/L hydrochloric acid solution with the concentration of 10mL and 44mL of ethanol into a round-bottom flask, stirring for 3min, adding 2.7g of the intermediate product 4, stirring for 12h at room temperature, adding 10 mass percent sodium carbonate solution to adjust the pH value to 7, washing for 5 times by using acetone, carrying out suction filtration, carrying out vacuum drying at 60 ℃, dialyzing for 12h in a dialysis bag after drying, precipitating by using acetone, carrying out suction filtration, and drying to obtain the modified chitosan.

The modified chitosans of examples 1-3 were subjected to mouse oral test:

15 mice are selected and evenly divided into 3 groups, the modified chitosan obtained in the examples 1-3 is fed to the mice respectively, each mouse is fed with 2.5g of the modified chitosan, the feeding amount and the water intake of the mice are kept consistent, and whether the mice show abnormal performance within 3 days is observed, and test results show that the 15 mice have no abnormal performance, which indicates that the modified chitosan prepared by the method is safe and non-toxic.

Example 4

A mixed bean processing technology for enhancing the nutrient content of staple food comprises the following steps:

firstly, red beans, mung beans, hyacinth beans, kidney beans and chickpeas are mixed according to the mass ratio of 1: 1: 1: 1: 1, cleaning after mixing, soaking in a sodium hydroxide solution with the concentration of 0.05mol/L for 17 hours, adding water, grinding into slurry, sieving with a 150-mesh sieve, collecting soybean milk, adding acetic acid into the soybean milk to adjust the pH value to 6, standing for 12 hours, carrying out centrifugal treatment at the rotation speed of 1500r/min for 10 minutes, taking a precipitate, stirring the precipitate in an ether solution for 20 minutes, carrying out suction filtration, and collecting a filter cake to obtain a crude extract;

secondly, adding the crude extract and water into a reactor, stirring and mixing for 20min, adding ethanol, stirring for 20min at a rotation speed of 167r/min, centrifuging, and collecting precipitate to obtain the hybrid bean protein;

adding 5.8g of phaseolin and 15mL of water into a reaction container, performing ultrasonic dispersion for 20min at the frequency of 40kHz, then adding 0.5g of sodium trimetaphosphate, adjusting the pH value to 9 by using a sodium hydroxide solution with the concentration of 1mol/L, stirring and reacting for 2h in a water bath at the temperature of 55 ℃, then adding a hydrochloric acid solution with the concentration of 1mol/L to adjust the pH value to 7, finally dialyzing for 72h in distilled water, replacing distilled water every 6h, and performing freeze drying for 24h at the temperature of-45 ℃ to obtain modified protein;

fourthly, mixing the modified protein and the modified chitosan in the example 1 according to the mass ratio of 100: 0.8, mixing uniformly to obtain the mixed bean extract for enhancing the nutrient content of the staple food.

Example 5

A mixed bean processing technology for enhancing the nutrient content of staple food comprises the following steps:

firstly, red beans, mung beans, hyacinth beans, kidney beans and chickpeas are mixed according to the mass ratio of 1: 1: 1: 1: 1, cleaning after mixing, soaking in a sodium hydroxide solution with the concentration of 0.05mol/L for 17 hours, adding water, grinding into slurry, sieving with a 150-mesh sieve, collecting soybean milk, adding acetic acid into the soybean milk to adjust the pH value to 6, standing for 12 hours, carrying out centrifugal treatment at the rotation speed of 1500r/min for 10 minutes, taking a precipitate, stirring the precipitate in an ether solution for 20 minutes, carrying out suction filtration, and collecting a filter cake to obtain a crude extract;

secondly, adding the crude extract and water into a reactor, stirring and mixing for 20min, adding ethanol, stirring for 20min at the rotating speed of 172r/min, centrifuging, and collecting precipitate to obtain the hybrid bean protein;

thirdly, adding 6.1g of phaseolin and 17mL of water into a reaction container, performing ultrasonic dispersion for 20min at the frequency of 45kHz, then adding 0.8g of sodium trimetaphosphate, adjusting the pH value to 9 by using a sodium hydroxide solution with the concentration of 1mol/L, stirring and reacting for 2h in a water bath at the temperature of 55 ℃, then adding a hydrochloric acid solution with the concentration of 1mol/L to adjust the pH value to 7, finally dialyzing for 72h in distilled water, replacing distilled water every 6h, and performing freeze drying for 24h at the temperature of-45 ℃ to obtain modified protein;

fourthly, mixing the modified protein and the modified chitosan in the example 2 according to the mass ratio of 100: 1.0, and uniformly mixing to obtain the mixed bean extract for enhancing the nutrient content of the staple food.

Example 6

A mixed bean processing technology for enhancing the nutrient content of staple food comprises the following steps:

firstly, red beans, mung beans, hyacinth beans, kidney beans and chickpeas are mixed according to the mass ratio of 1: 1: 1: 1: 1, cleaning after mixing, soaking in a sodium hydroxide solution with the concentration of 0.05mol/L for 17 hours, adding water, grinding into slurry, sieving with a 150-mesh sieve, collecting soybean milk, adding acetic acid into the soybean milk to adjust the pH value to 6, standing for 12 hours, carrying out centrifugal treatment at the rotation speed of 1500r/min for 10 minutes, taking a precipitate, stirring the precipitate in an ether solution for 20 minutes, carrying out suction filtration, and collecting a filter cake to obtain a crude extract;

secondly, adding the crude extract and water into a reactor, stirring and mixing for 20min, adding ethanol, stirring for 20min at the rotation speed of 174r/min, centrifuging, and collecting precipitate to obtain the hybrid bean protein;

adding 6.3g of phaseolin and 18mL of water into a reaction container, performing ultrasonic dispersion for 20min at the frequency of 50kHz, then adding 1.1g of sodium trimetaphosphate, adjusting the pH value to 9 by using a sodium hydroxide solution with the concentration of 1mol/L, stirring and reacting for 2h in a water bath at the temperature of 55 ℃, then adding a hydrochloric acid solution with the concentration of 1mol/L to adjust the pH value to 8, finally dialyzing for 72h in distilled water, replacing distilled water every 6h, and performing freeze drying for 24h at the temperature of-45 ℃ to obtain modified protein;

fourthly, mixing the modified protein and the modified chitosan in the embodiment 3 according to the mass ratio of 100: 1.5 mixing uniformly to obtain the mixed bean extract for enhancing the nutrient content of the staple food.

Comparative example 1

Red beans, mung beans, hyacinth beans, kidney beans and chickpeas are mixed according to the mass ratio of 1: 1: 1: 1: 1, cleaning, soaking in a sodium hydroxide solution with the concentration of 0.05mol/L for 17 hours, adding water, grinding into slurry, sieving with a 150-mesh sieve, collecting soybean milk, adding acetic acid into the soybean milk to adjust the pH value to 6, standing for 12 hours, centrifuging at the rotation speed of 1500r/min for 10 minutes, taking a precipitate, stirring the precipitate in an ether solution for 20 minutes, carrying out suction filtration, and collecting a filter cake to obtain the mixed bean extract.

Comparative example 2

The comparative example is the soy protein prepared in example 5 of the preparation method of the soy protein special for dairy products published in CN 102389021B.

Comparative example 3

This comparative example is a soy protein sold by Anyang Beijia food Co.

The extract of the mixed beans obtained in examples 4 to 6, the extract of the mixed beans in comparative example 1, and the soy proteins in comparative examples 2 and 3 were subjected to a performance test in the following procedure:

respectively mixing each group of samples to be detected and deionized water according to the weight ratio of 1 g: 10mL are uniformly mixed, 20g of wheat flour is added, dough with moderate hardness is obtained by supplementing the same water quantity and flour, then cutting is carried out to obtain 5 groups of fresh wet noodles, then taste test and fresh-keeping test can be carried out on the fresh wet noodles, the taste test is to select 15 volunteers, evaluation and scoring are carried out on the cooked noodles, the noodle score is from low to high 0-5, the fresh-keeping performance is to take part of the fresh wet noodles to keep fresh for 7 days in a refrigerator with the temperature of 8 ℃, the phenomena of mould and rot are observed, and the test results are shown in the following table:

item	Evaluation of mouthfeel	Preserving fresh wet noodles in refrigerator at 8 deg.C for 7 days
			Example 4	4.8	Without change
Example 5	4.9	Without change
			Example 6	4.9	Without change
Comparative example 1	4.2	Sticky and mold growing on the surface
			Comparative example 2	3.1	Sticky and mold growing on the surface
Comparative example 3	3.8	Become sticky and no mold on the surface

As can be seen from the above table, the noodle products of examples 4-6 have higher taste scores and better fresh-keeping effect, so the mixed bean extract obtained by the mixed bean treatment process provided by the invention can effectively improve the nutrient content of the staple food and has fresh-keeping and preservative effects.

In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing is illustrative and explanatory only and is not intended to be exhaustive or to limit the invention to the precise embodiments described, and various modifications, additions, and substitutions may be made by those skilled in the art without departing from the scope of the invention or exceeding the scope of the claims.