阅读说明：本技术 一种利用花生粕制备多肽的方法及其应用 (Method for preparing polypeptide by using peanut meal and application thereof ) 是由 张莉 王子萌 韩宝芹 彭睿 刘万顺 于 2020-04-03 设计创作，主要内容包括：本发明涉及一种利用花生粕制备多肽的方法及其应用,所述方法包括：将花生粕依次进行预处理、灭菌、酶解、固液分离以及浓缩干燥；所述酶解包括如下步骤：在灭菌后的所述花生粕中加入中性蛋白酶,于40～50℃下酶解4～8小时,酶解过程中pH保持在6.5～7.5。本发明提供的生产工艺可将脱脂花生粕中的营养成分进行降解,使其能为易被人体吸收且营养丰富的低脂花生多肽粉,水解度达到69％,脂肪含量低至0.77％,多肽占比大,且完全酶解了过敏原Ara h1。本生产工艺简单、条件温和、生产时间短,成本低,适合大规模工业化生产,有效提高了花生粕的利用率和附加值。(The invention relates to a method for preparing polypeptide by using peanut meal and application thereof, wherein the method comprises the following steps: sequentially carrying out pretreatment, sterilization, enzymolysis, solid-liquid separation, concentration and drying on the peanut meal; the enzymolysis comprises the following steps: and adding neutral protease into the sterilized peanut meal, performing enzymolysis for 4-8 hours at 40-50 ℃, and keeping the pH value at 6.5-7.5 in the enzymolysis process. The production process provided by the invention can degrade the nutritional ingredients in the defatted peanut meal to make the defatted peanut meal into low-fat peanut polypeptide powder which is easy to absorb by human bodies and rich in nutrition, the hydrolysis degree reaches 69%, the fat content is as low as 0.77%, the polypeptide accounts for a large proportion, and the allergen Ara h1 is completely enzymolyzed. The production process is simple, mild in condition, short in production time and low in cost, is suitable for large-scale industrial production, and effectively improves the utilization rate and the additional value of the peanut meal.)

1. A method for preparing polypeptide by using peanut meal is characterized by comprising the following steps:

sequentially carrying out pretreatment, sterilization, enzymolysis, solid-liquid separation, concentration and drying on the peanut meal;

the enzymolysis comprises the following steps: and adding neutral protease into the sterilized peanut meal, performing enzymolysis for 4-8 hours at 40-50 ℃, and keeping the pH value at 6.5-7.5 in the enzymolysis process.

2. The method of claim 1, wherein the conditions of enzymatic hydrolysis are: carrying out enzymolysis for 6-8 hours at 45-50 ℃, and keeping the pH value at 7-7.5 in the enzymolysis process.

3. The method according to claim 1 or 2, wherein the peanut meal is a byproduct obtained after peanut oil extraction.

4. The method according to any one of claims 1 to 3, wherein the pH value is adjusted by 3 to 4 mol/L of food grade sodium carbonate during the enzymatic hydrolysis.

5. The method according to any one of claims 1 to 4, wherein the pretreatment is to add water to the peanut meal for soaking and then grinding, and the concentration of the peanut meal is 12-14%.

6. The method according to claim 5, wherein the sterilization is boiling the ground peanut meal at 95-105 ℃ for 15-25 minutes.

7. The method according to any one of claims 1 to 6, wherein the solid-liquid separation is performed by filtering slurry obtained after the peanut meal is subjected to enzymolysis through 400-mesh filter cloth.

8. The method according to any one of claims 1 to 7, wherein the concentration and drying are carried out by subjecting a liquid fraction obtained by solid-liquid separation to a vacuum concentration method to obtain a polypeptide concentrate and then to spray drying.

9. Use of the method of any one of claims 1-8 for preparing peanut polypeptide powder.

10. Use of the method of any one of claims 1-8 for the preparation of a feed or fertilizer.

Technical Field

The invention relates to the field of food processing, in particular to a method for preparing polypeptide by using peanut meal and application thereof.

Background

Peanut is a common oil crop, and the utilization mode of the peanut mainly comprises oil extraction and peanut food. During the oil extraction process, a large amount of byproducts are generated, and the byproducts are rich in nutritional ingredients such as proteins, sugars and phenols, but the utilization rate is low at present. The byproducts are comprehensively utilized and subjected to deep processing, so that the industrial chain can be prolonged, the economic value of the peanuts can be improved, the resource waste can be reduced, and the environmental pollution caused by the waste of the byproducts can be avoided.

The peanut meal is a main byproduct obtained after peanut oil extraction by pressing, contains 30-50% of protein, has complete amino acid types and has potential comprehensive utilization value. However, the peanut meal obtained by the squeezing method is seriously denatured in protein and reduced in nutritive value, so that the peanut meal is influenced to be developed and utilized and is mostly used as feed or fertilizer. Peanut polypeptide generally refers to peanut low peptide, and is a short-chain peptide mixture obtained by carrying out enzymatic hydrolysis on peanut protein, wherein the amino acid composition of the short-chain peptide mixture is close to that of a human body, and essential amino acid is well balanced and rich in content. The peanut protein is hydrolyzed properly to improve the nutrient utilization rate, has better nutrient performance compared with protein, has higher absorptivity of low peptide than protein, and is absorbed and utilized by organisms through small intestinal mucosa more easily and more quickly. Peanut polypeptides are reported to have a number of functional properties: very low hypersensitivity; promoting fat metabolism, reducing cholesterol and blood lipid; lowering blood pressure; oxidation resistance; antibacterial; enhancing muscle motility, accelerating muscle erythrocyte recovery, and resisting fatigue; the immunity is improved; promoting the growth and metabolism of beneficial flora such as bifidobacterium and the like; sobering up effect, etc. The peanut peptide has excellent processing characteristics and safe eating, can be applied to infant formula food, nutrition-enriched food, supplementary food, fermented food, protein beverage, medical food, athlete food and the like, and is a functional factor with great development potential.

Enzymatic hydrolysis is currently the most commonly used method for the preparation of peanut peptides. The enzymolysis method is to utilize protease to carry out catalytic hydrolysis on protein molecules under certain conditions, so that macromolecular proteins are degraded into micromolecules with different chain lengths. Compared with acid-base catalyzed hydrolysis reaction, the method has higher safety, mild reaction conditions, no pronation phenomenon, less side reactions, easily controlled process, less damage to amino acid and other nutrient components, and the peptides and amino acid generated by hydrolysis are easier to be absorbed and digested by human body. The utilization rate of the protein of the peanut meal subjected to enzymatic hydrolysis is higher than that of the peanut meal protein which is used as feed and then converted into animal protein. The enzymatic hydrolysis process of the peanut meal is simple, convenient to operate, low in investment and cost, suitable for large-scale production and wide in application prospect.

Disclosure of Invention

The invention provides a method for preparing polypeptide by using peanut meal and application thereof, which directly carries out enzymolysis treatment on the peanut meal, simplifies the production process and has higher yield and purity.

In a first aspect, the present application provides a method for producing a polypeptide using peanut meal, comprising:

sequentially carrying out pretreatment, sterilization, enzymolysis, solid-liquid separation, concentration and drying on the peanut meal;

the enzymolysis comprises the following steps: and adding neutral protease into the sterilized peanut meal, performing enzymolysis for 4-8 hours at 40-50 ℃, and keeping the pH value at 6.5-7.5 in the enzymolysis process.

The enzymolysis condition is preferably enzymolysis for 6-8 hours at 45-50 ℃, and the pH value is kept at 7-7.5 in the enzymolysis process.

Optimally, enzymolysis is carried out for 6 hours at the temperature of 45 ℃, and the pH value is kept between 7 and 7.5 in the enzymolysis process.

Furthermore, the peanut meal is a byproduct obtained after peanut oil extraction.

The byproducts of the peanut oil after pressing contain a large amount of protein, a small amount of sugar and fat, some starch and dietary fiber exist, the water content is low, partial impurities are removed firstly by performing protein extraction and other steps on the general peanut meal for protein recovery, but the protein extraction process is tedious on the one hand, other acid and alkali and other chemical reagents need to be additionally introduced, the production cost is increased, the taste of the product in the future can be adversely affected by excessive addition of the acid and alkali, and the loss of some nutrient substances can be reduced. On the other hand, due to the extraction rate, the raw material inevitably has a large loss after the process of extracting the protein, further increasing the production cost.

Compared with the prior art, the method omits a protein extraction step, raw materials are not purified, the tight structure of the peanut protein is loosened only through necessary pretreatment work, the subsequent enzymolysis process is easier to carry out through exposing enzyme binding sites, and the nutrient components are completely reserved in the raw materials for utilization as far as possible. According to the invention, by monitoring the change of the recovery rate of the protein in the production process, the recovery rate is increased to be more than 4 times before production after 4 hours of production, which indicates that most of the protein in the raw materials is hydrolyzed into micromolecular polypeptide and released in a reaction system, and the protein can be extracted and utilized through the subsequent production process. In addition, the content of protein and polypeptide in the raw materials and products before and after production is measured, and the finding shows that the enzymolysis production process has better hydrolysis degree and protein utilization rate compared with the method for recovering protein after protein extraction.

Further, in the enzymolysis process, the pH value is adjusted through 3-4 mol/L food-grade sodium carbonate.

The method comprises the steps of preparing a reaction system, adding a protease, adding a high-concentration alkali liquor, and carrying out a reaction, wherein the alkali liquor is food-grade sodium carbonate of 4 mol/L, the addition of water in the reaction system can be reduced to the greatest extent by the high-concentration alkali liquor, the cost is reduced for subsequent drying, the pH change is monitored in real time in the reaction process, and the pH of the system is adjusted in time when the pH is lower than 6, so that the enzymolysis effect can be ensured, the protease can continuously exert the activity, the addition of.

Further, the pretreatment is to soak the peanut meal in water and then grind the peanut meal into pulp, wherein the concentration of the peanut meal is 12-14%.

Further, the sterilization is to boil the ground peanut meal at 95-105 ℃ for 15-25 minutes.

Further, the solid-liquid separation is that the slurry obtained after the peanut meal is subjected to enzymolysis is filtered by 400-mesh filter cloth.

Further, the concentration and drying are carried out by preparing a polypeptide concentrated solution from a liquid part obtained by solid-liquid separation by a vacuum concentration method and then carrying out spray drying.

According to the invention, peanut meal is subjected to the steps, the peanut meal is prepared into peanut polypeptide powder with small molecular weight, the peanut polypeptide powder is easily absorbed and utilized by a human body at 3000Da, filter residues obtained by solid-liquid separation after enzymolysis are simply treated, bitter taste and other peculiar smell caused by enzymolysis can be removed after water washing, and the filter residues can be further processed into fertilizer or feed again.

The invention provides a method for preparing polypeptide by using peanut meal and application thereof, and the method has the following beneficial effects:

according to the method for preparing the low-fat peanut polypeptide powder by performing enzymolysis on the peanut meal by using the neutral protease, a high product yield of about 31% -43% is achieved within a short 6-hour enzymolysis time; the ratio of the polypeptide is large, and reaches 41-43 percent; the enzymolysis effect is good, and the hydrolysis degree reaches 67 to 69 percent; the molecular weight of peanut peptide is distributed below 3000Da in concentration, and accounts for 86-90%, so that the molecular weight of peanut peptide is small, the peanut peptide is easy to be absorbed and utilized by human body, and the fat content in the obtained polypeptide powder is low, and is about 0.77-0.85%; meanwhile, the major allergen Ara h1 in the peanuts is completely enzymolyzed.

The invention omits other complicated process steps of protein extraction, desalination and the like, directly carries out enzymolysis on the raw materials after simple treatment, and obtains higher product yield and better enzymolysis effect only through one-time protease enzymolysis, thereby greatly simplifying the production process, shortening the production time, reducing the cost and reducing the use of other chemical reagents.

The method has the advantages of simple production process, mild conditions, short production time and low cost, but has the advantages of good enzymolysis effect, high yield, high short peptide content, low molecular weight and low fat content, and is suitable for large-scale industrial production, and filter residues obtained by the solid-liquid separation part after enzymolysis can be processed into fertilizers or feeds through simple treatment, so that the recycling of the peanut meal is maximized.

Drawings

FIG. 1 is a graph showing the relationship between the enzymolysis time and the hydrolysis measured in example 1 of the present invention;

FIG. 2 is a graph showing the measured solids content of filtrates obtained at different enzymatic hydrolysis times in example 1 of the present invention;

FIG. 3 is a HP L C map of the molecular weight distribution of the short peptide measured in example 1 of the present invention;

FIG. 4 is a SDS-PAGE electrophoresis of the reduced fat peanut polypeptides prepared in example 1 of the invention.

Detailed Description

The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

The neutral protease used in the following examples was purchased from Wunpuk Biotech, Inc.; the sodium carbonate is food grade.

The peanut meal used in the following examples had a protein content of 51% and a fat content of 9.67%. The determination of the protein content is carried out by a Kjeldahl method in a first method of national standard GB/T5009.5-2016; the fat content is measured by a soxhlet extraction method in the first method of the national standard GB/T5009.6-2016.

The method for measuring the yield of the short peptide in the following embodiment adopts a trichloroacetic acid soluble nitrogen method; the degree of hydrolysis is expressed by the protein recovery; the fat content is measured by a soxhlet extraction method in a first method of national standard GB/T5009.6-2016; the molecular weight distribution of the peanut peptide is determined by adopting high performance liquid chromatography for analysis.