阅读说明：本技术 一种小麦胚芽多肽速食粉的制备方法 (Preparation method of wheat germ polypeptide instant powder ) 是由 徐静 许红梅 武杰 周小满 周佳佳 于 2019-11-14 设计创作，主要内容包括：本发明公开一种小麦胚芽多肽速食粉的制备方法：采用酶解法和发酵法联合分解小麦胚芽,高温灭酶灭菌、干燥,得到多肽含量≥25％的发酵干粉,与低脂奶粉、蛋清粉、核桃粉、甜菊糖、麦芽糊精复配制出多肽速食粉。本发明首次采用酶解法和发酵法联合分解麦胚蛋白,使其降解为小分子多肽、寡肽及游离的氨基酸,可被人体直接吸收利用,羧肽酶A进一步作用于其他蛋白酶和微生物降解后产生的多肽链,从肽链的C端逐个降解、释放游离氨基酸,大大降低了多肽的分子量,同时,发酵过程,在地衣芽孢杆菌作用下,还产生独特酱香型风味物质,在酿酒酵母菌作用下、乳酸菌的同型发酵或异型发酵作用下,产生乙醇和乳酸,增加小麦胚芽粉的风味物质,丰富口味。(The invention discloses a preparation method of wheat germ polypeptide instant powder, which comprises the following steps: decomposing wheat germ by enzymolysis and fermentation, deactivating enzyme at high temperature, sterilizing, drying to obtain fermented dry powder with polypeptide content not less than 25%, and mixing with low fat milk powder, egg white powder, walnut powder, steviosin and maltodextrin to obtain the polypeptide instant powder. The wheat germ protein is degraded into micromolecular polypeptide, oligopeptide and free amino acid by combining an enzymolysis method and a fermentation method for the first time, the micromolecular polypeptide, the oligopeptide and the free amino acid can be directly absorbed and utilized by a human body, the carboxypeptidase A further acts on other proteases and polypeptide chains generated after microbial degradation, the free amino acid is degraded and released one by one from the C end of the peptide chain, the molecular weight of the polypeptide is greatly reduced, meanwhile, a unique Maotai-flavor substance is generated under the action of the bacillus licheniformis in the fermentation process, and ethanol and lactic acid are generated under the action of saccharomyces cerevisiae and homofermentation or heterofermentation of lactic acid bacteria, so that the flavor substances of the wheat germ powder are increased, and the taste is enriched.)

1. A preparation method of wheat germ polypeptide instant powder is characterized by comprising the following steps: decomposing wheat germ by enzymolysis and fermentation, deactivating enzyme at high temperature, sterilizing, drying to obtain fermented dry powder with polypeptide content not less than 25%, and mixing with low fat milk powder, egg white powder, walnut powder, steviosin and maltodextrin to obtain polypeptide instant powder; the method specifically comprises the following steps:

s1: crushing:

a. coarse crushing: crushing wheat germs to 20-35 meshes to obtain wheat germ coarse powder;

b. superfine grinding: crushing the obtained wheat germ coarse powder to 200-600 meshes by using an air-flow type ultrafine pulverizer to obtain wheat germ ultrafine powder;

s2: saccharification treatment: and (3) adding the wheat germ superfine powder obtained in the step (S1) into water, wherein the ratio of material to water is 1: (2.5-5), adjusting the pH value to 4.0-4.5, adding 0.5-2% of saccharifying enzyme and 0.5-3% of amylase, and saccharifying in a water bath at 60 ℃ for 6-12 h under the auxiliary action of ultrasonic waves;

s3: combined decomposition of germ protein:

a. aerobic fermentation: adjusting the pH value of the wheat germ saccharified material obtained in the step S2 to 7.0, adding compound protease with the enzyme adding amount of 0.8-2.2%, inoculating aerobic fermentation bacteria with the inoculation amount of 1-5%, introducing air, performing aerobic fermentation for 18-48 h at 30-35 ℃ in combination with an enzymolysis method;

b. anaerobic fermentation: introducing high-purity nitrogen into the fermented material after aerobic fermentation, inoculating anaerobic fermentation bacteria with the inoculation amount of 1-5%, strictly sealing, and carrying out anaerobic fermentation at 35-38 ℃ for 36-72 h;

s4: high-temperature enzyme inactivation, sterilization and drying: treating the fermentation product obtained in the step S3 for 15min by high-temperature steam at 121 ℃, inactivating enzymes, sterilizing, and performing spray drying to obtain dry fermentation powder with the water content of less than or equal to 1% and the polypeptide content of more than or equal to 25%;

s5: compounding: mixing the fermented dry powder obtained in the step S4 with low-fat milk powder, egg white powder, walnut powder, stevioside and maltodextrin; in each part of wheat germ polypeptide instant powder, the components are compounded in the following mass percentage: 2.5-3.5% of low-fat milk powder, 0.4-1.2% of egg white powder, 1.6-2% of walnut powder, 0.1-0.3% of stevioside, 3-5% of maltodextrin and the balance of fermented dry powder obtained from S4.

2. The method for preparing wheat germ polypeptide instant powder as claimed in claim 1, wherein the ultrasonic frequency is 25-50 KHz.

3. The method for preparing wheat germ polypeptide instant powder as claimed in claim 1, wherein the compound protease is selected from neutral protease, papain, bromelain, carboxypeptidase A according to the ratio of 1: (1.1-1.3): (0.6-0.8): (0.1-0.2) in mass ratio.

4. The method for preparing wheat germ polypeptide instant powder as claimed in claim 1, wherein the aerobic fermentation bacteria are saccharomyces cerevisiae, bacillus subtilis and bacillus licheniformis according to a ratio of 1: (1-1.5): (0.8-1.2) in mass ratio.

5. The method for preparing wheat germ polypeptide instant powder as claimed in claim 1, wherein the anaerobic fermentation bacteria are selected from lactobacillus casei, leuconostoc mesenteroides, lactobacillus plantarum according to a ratio of 1: (1.1-1.5): (0.5-1) in mass ratio.

Technical Field

The invention belongs to the technical field of wheat germ deep processing, and particularly relates to a preparation method of wheat germ polypeptide instant powder.

Background

The wheat germ has a protein content of more than 31%, wherein the wheat globulin accounts for 18.9%, the glutenin accounts for 0.30-0.37%, and the gliadin accounts for 14.0%, and the wheat germ is an important source of high-quality protein, contains 8 amino acids essential to human body, particularly contains 18.5% of lysine which is 6-7 times higher than that of rice and white flour. The wheat germ contains linoleic acid 60%, wherein 80% is polyunsaturated fatty acid, and linoleic acid is the most important one of three essential fatty acids, and has effects of reducing blood lipid and preventing atherosclerosis.

Due to the characteristics of high protein and high nutritional value of wheat germs, the development of novel functional meal replacement products by utilizing the wheat germs becomes a research hotspot in the field of food processing, such as a patent of CN2014100329-50.2, discloses wheat germ instant powder and a preparation method thereof, such as a patent of CN201610-126731.X, discloses infant edible powder processed by taking the wheat germs as a main raw material and a preparation method thereof, such as a patent of CN201811084332.7, and discloses a preparation method of wheat germ edible powder suitable for people with three highs. However, the existing wheat germ meal replacement powder is prepared by directly mixing wheat germ powder with other raw materials, protein in the wheat germ powder still exists in a macromolecular form, other nutritional ingredients are not fully released, and the flavor is single.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a preparation method of wheat germ polypeptide instant powder.

The technical scheme of the invention is summarized as follows:

a preparation method of wheat germ polypeptide instant powder comprises the following steps: decomposing wheat germ by enzymolysis and fermentation, deactivating enzyme at high temperature, sterilizing, drying to obtain fermented dry powder with polypeptide content not less than 25%, and mixing with low fat milk powder, egg white powder, walnut powder, steviosin and maltodextrin to obtain polypeptide instant powder; the method specifically comprises the following steps:

s1: crushing:

a. coarse crushing: crushing wheat germs to 20-35 meshes to obtain wheat germ coarse powder;

b. superfine grinding: crushing the obtained wheat germ coarse powder to 200-600 meshes by using an air-flow type ultrafine pulverizer to obtain wheat germ ultrafine powder;

s2: saccharification treatment: and (3) adding the wheat germ superfine powder obtained in the step (S1) into water, wherein the ratio of material to water is 1: (2.5-5), adjusting the pH value to 4.0-4.5, adding 0.5-2% of saccharifying enzyme and 0.5-3% of amylase, and saccharifying in a water bath at 60 ℃ for 6-12 h under the auxiliary action of ultrasonic waves;

s3: combined decomposition of germ protein:

a. aerobic fermentation: adjusting the pH value of the wheat germ saccharified material obtained in the step S2 to 7.0, adding compound protease with the enzyme adding amount of 0.8-2.2%, inoculating aerobic fermentation bacteria with the inoculation amount of 1-5%, introducing air, performing aerobic fermentation for 18-48 h at 30-35 ℃ in combination with an enzymolysis method;

b. anaerobic fermentation: introducing high-purity nitrogen into the fermented material after aerobic fermentation, inoculating anaerobic fermentation bacteria with the inoculation amount of 1-5%, strictly sealing, and carrying out anaerobic fermentation at 35-38 ℃ for 36-72 h;

s4: high-temperature enzyme inactivation, sterilization and drying: treating the fermentation product obtained in the step S3 for 15min by high-temperature steam at 121 ℃, inactivating enzymes, sterilizing, and performing spray drying to obtain dry fermentation powder with the water content of less than or equal to 1% and the polypeptide content of more than or equal to 25%;

s5: compounding: mixing the fermented dry powder obtained in the step S4 with low-fat milk powder, egg white powder, walnut powder, stevioside and maltodextrin; the wheat germ polypeptide instant powder comprises the following components in percentage by weight: 2.5-3.5% of low-fat milk powder, 0.4-1.2% of egg white powder, 1.6-2% of walnut powder, 0.1-0.3% of stevioside, 3-5% of maltodextrin and the balance of fermented dry powder obtained from S4.

Preferably, the frequency of the ultrasonic wave is 25-50 KHz.

Preferably, the compound protease is prepared from neutral protease, papain, bromelain and carboxypeptidase A according to the weight ratio of 1: (1.1-1.3): (0.6-0.8): (0.1-0.2) in mass ratio.

Preferably, the aerobic fermentation bacteria are prepared from saccharomyces cerevisiae, bacillus subtilis and bacillus licheniformis according to the proportion of 1: (1-1.5): (0.8-1.2) in mass ratio.

Preferably, the anaerobic zymocyte is prepared from lactobacillus casei, leuconostoc mesenteroides and lactobacillus plantarum according to the weight ratio of 1: (1.1-1.5): (0.5-1) in mass ratio.

The invention has the beneficial effects that:

1. the invention uses the superfine grinding technology to destroy the wheat germ cell structure in advance, so that the cell wall is broken, the extraction of wheat germ protein is easy, the wheat germ starch and polysaccharide are fully dissolved out, then saccharifying enzyme and amylase are used for hydrolyzing the starch and macromolecular polysaccharide, the starch and the macromolecular polysaccharide are decomposed into glucose, maltose and maltodextrin which can be directly used by microorganisms, so as to provide carbon source support for the subsequent combined fermentation, furthermore, the enzyme hydrolysis method and the fermentation method are firstly used for jointly decomposing the wheat germ protein, so that the wheat germ protein is degraded into micromolecular polypeptide, oligopeptide and free amino acid, the polypeptide enters the human body, the polypeptide can be directly absorbed and utilized, the nutritive value of the wheat germ powder is obviously improved, carboxypeptidase A further acts on other proteases and polypeptide chains generated after the degradation of the microorganisms, the C end of the polypeptide chains is degraded one by one, the free amino acid is released, the molecular weight of the polypeptide is greatly reduced, and simultaneously, in the aerobic fermentation process, under the action of bacillus licheniformis, unique Maotai-flavor substances are also generated, and in the anaerobic fermentation process, under the action of saccharomyces cerevisiae and the action of homolactic fermentation or heterolactic fermentation of lactic acid bacteria, ethanol and lactic acid are generated, so that the flavor substances of the wheat germ powder are increased, and the taste is enriched.

2. According to the invention, the wheat germ fermented dry powder with the polypeptide content of more than or equal to 25% is compounded with the low-fat milk powder, the egg white powder, the walnut powder and the stevioside, so that animal protein is supplemented, the variety of high-quality protein is enriched, the sweetness of the stevioside is 250-450 times that of the cane sugar, the calorific value of the stevioside is only 1/300 of the cane sugar, the stevioside cannot be absorbed after being taken into a human body, and heat is not generated, and meanwhile, the starch is converted into other flavor substances in the fermentation process, so that the instant powder disclosed by the invention is extremely low in sugar content and is suitable for being eaten by.

3. The wheat germ polypeptide instant powder has good fluidity and is instant, and can be dissolved in water at 50 ℃ for less than or equal to 12 s; the wheat germ polypeptide paste prepared by brewing is light yellow, glossy, uniform in color, free of other mixed colors and spots, uniform in texture, free of layering, caking, impurities and fiber suspension, good in taste, rich in wheat flavor, sauce flavor and wine flavor, sour and sweet, fine and smooth in taste, moderate in viscosity, free of granular feeling and free of rough feeling.

Drawings

FIG. 1 is a flow chart of a preparation method of wheat germ polypeptide instant powder.

Detailed Description

The present invention is further described in detail below with reference to examples so that those skilled in the art can practice the invention with reference to the description.