阅读说明：本技术 一种从乳清废液中提取水解蛋白的制备方法 (Preparation method for extracting hydrolyzed protein from whey waste liquid ) 是由 王冬冬 于 2020-07-23 设计创作，主要内容包括：本发明公开了一种从乳清废液中提取水解蛋白的制备方法,利用絮凝剂聚合氯化铝和聚丙烯酰胺将蛋白富集后,采用高温高压技术使絮凝剂对蛋白的结合力减弱,后采用复合酶解技术直接对絮凝蛋白进行酶解产生小分子肽及氨基酸,解决了传统方法中蛋白提取率低问题,降低了乳清废液提取水解蛋白的生产成本,提高了产品的附加值,提升产业经济效益；此外,本发明选用具有高度定向性的复合酶制剂,不受絮凝剂影响,可以直接将絮凝剂结合的蛋白进行分解成为小分子肽及氨基酸,产品可直接应用于动物饲料及有机化肥,增加动物或植物的氮源摄入及吸收,解决了蛋白的应用问题。(The invention discloses a preparation method for extracting hydrolyzed protein from whey waste liquid, which is characterized in that after protein is enriched by utilizing flocculating agents polyaluminium chloride and polyacrylamide, the binding force of the flocculating agents to the protein is weakened by adopting a high-temperature and high-pressure technology, and then the flocculated protein is directly subjected to enzymolysis by adopting a composite enzymolysis technology to generate small molecular peptides and amino acids, so that the problem of low protein extraction rate in the traditional method is solved, the production cost for extracting the hydrolyzed protein from the whey waste liquid is reduced, the additional value of products is improved, and the industrial economic benefit is improved; in addition, the invention selects the complex enzyme preparation with high directionality, is not influenced by the flocculant, can directly decompose the protein combined with the flocculant into small molecular peptides and amino acids, can be directly applied to animal feeds and organic fertilizers, increases the nitrogen source intake and absorption of animals or plants, and solves the application problem of the protein.)

1. A preparation method for extracting hydrolyzed protein from whey waste liquid is characterized by comprising the following steps:

(1) flocculation and precipitation: adding a flocculating agent into the whey waste liquid, uniformly stirring, and adjusting the pH value of the whey waste liquid to 5.0-6.0 to continuously precipitate protein;

(2) centrifugal separation: centrifuging the whey waste liquid after flocculation precipitation for 20min at 4000-6000 rpm at 25 ℃;

(3) shearing and emulsifying: adding 3 times of purified water into the centrifuged heavy phase for washing, shearing and emulsifying by using a high-speed shearing emulsifying machine, and then centrifugally separating to separate out the heavy phase and the light phase;

(4) and (3) heating for dissociation: adding 2 times of purified water into the centrifuged heavy phase in the step (3), adjusting the pH value to 6.5, heating the mixture in a pressure tank at 120 ℃ for 30min to denature and dissociate the flocculated protein;

(5) cooling and enzymolysis: after heating, introducing cooling water into the interlayer of the pressure tank to reduce the temperature of the feed liquid to 50-55 ℃, adding a complex enzyme preparation, and performing heat preservation and enzymolysis for 15 hours;

(6) sterilization and enzyme deactivation: after the enzymolysis is finished, sterilizing and inactivating enzyme in a pressure tank at 120 ℃ for 10 min;

(7) centrifugal drying: and cooling the feed liquid, centrifuging, and performing spray drying on the light phase to obtain the final product.

2. The method according to claim 1, wherein the flocculant in step (1) is one or a mixture of polyaluminium chloride and polyacrylamide.

3. The method according to claim 1, wherein the flocculant in step (1) is a mixture of polyaluminium chloride and polyacrylamide at a mass ratio of 5: 1.

4. The method for preparing the hydrolyzed protein extracted from the whey waste liquid according to claim 1, wherein the flocculant is added in the step (1) in an amount of 3-5 g/L.

5. The method according to claim 1, wherein the flocculant is added in an amount of 3g/L to the whey waste liquid in the step (1).

6. The preparation method for extracting the hydrolyzed protein from the whey waste liquid according to claim 1, wherein the addition amount of the complex enzyme preparation in the step (5) is 6-8% of the mass ratio of the feed liquid.

7. The method for preparing hydrolyzed protein from whey waste liquid according to claim 1, wherein the complex enzyme preparation is a mixture of alkaline protease, complex protease and phytase, and the mass ratio is 10:2: 1.

8. The method according to claim 1, wherein the light phase after centrifugation in step (3) is reused in the oligosaccharide production process for producing oligosaccharides.

Technical Field

The invention relates to a preparation method for extracting hydrolyzed protein from whey waste liquid, in particular to a method for extracting the hydrolyzed protein from the whey waste liquid by utilizing protein flocculation and composite enzymolysis processes, belonging to the technical field of protein extraction.

Background

The soybean whey wastewater is a process wastewater discharged in the production of soybean protein (soybean protein concentrate or protein isolate). The production of the soybean protein concentrate and the protein isolate both take low-temperature defatted bean cypress as raw materials, and the production of the soybean protein concentrate generally realizes protein precipitation and separation through the technical processes of acid precipitation, alcohol precipitation, heat treatment and the like, so a large amount of whey wastewater can be generated in the production process of the soybean protein. The pH value of the whey waste liquid is about 4.5, the total solid content is generally 1.0-2.1%, wherein the sugar accounts for more than half, the soybean whey protein accounts for 0.1-0.5%, the BOD is as high as 5000-8000 mg/L, the COD is as high as 18000-20000 mg/L, and far exceeds the standard of the required discharge (the BOD of the discharge standard of China to the wastewater is less than or equal to 25mg/L, COD and less than or equal to 80 mg/L). For example, direct harmless treatment of whey wastewater (for example, patent CN 105439397A) not only increases production cost, but also causes waste of resources such as protein and oligosaccharide in whey wastewater, so resource utilization of whey wastewater becomes a technical problem to be solved urgently in the soybean protein industry.

The soybean whey has low protein content, the pretreatment of the soybean whey in the previous period is difficult to realize, the extraction of protein in the soybean whey under the condition of continuous production in a workshop is difficult, and the equipment investment is high. The most effective method for extracting the protein from the whey waste liquid is membrane extraction, but the extraction rate is low and is only about 5%, membrane pollution is easy to cause, and the production cost is high. If the protein is precipitated by directly adding the flocculating agent, the protein cannot be utilized due to high combination with the flocculating agent, and the produced protein cannot be directly applied and is not clear in application direction. In the prior art, patent CN110577565A discloses a method for recovering PA2 and psaLA from pea whey wastewater, which takes the pea whey wastewater containing protein generated in the processing process of pea protein as a raw material, selects natural cationic polysaccharide chitosan as a coagulant, and realizes the extraction, separation and purification of two kinds of pea whey protein PA2 and psa LA step by adjusting the complex coagulation condition; patent CN108191950A discloses a method for recovering protein from soybean whey wastewater, comprising the following steps: (1) adjusting the pH value of the soybean whey wastewater to be alkaline and then concentrating; (2) adjusting the protein concentration of the concentrated soy whey solution obtained in the step (1) to 12-16%, and performing spray drying to obtain the soy protein powder. Compared with the prior art, the technical problems of direct utilization of the flocculated protein, low protein extraction rate, high production cost and the like are not solved in the prior art.

Disclosure of Invention

In order to overcome the defects of the prior art and solve the problem that the flocculated protein cannot be directly utilized, the invention provides a preparation method for extracting the hydrolyzed protein from the whey waste liquid, wherein the protein is enriched by utilizing flocculating agents polyaluminium chloride and polyacrylamide, the binding force of the flocculating agents to the protein is weakened by adopting a high-temperature and high-pressure technology, and then the flocculated protein is directly subjected to enzymolysis by adopting a composite enzymolysis technology to generate small molecular peptides and amino acids, so that the problem of low protein extraction rate in the traditional method is solved, the production cost for extracting the hydrolyzed protein from the whey waste liquid is reduced, the additional value of the product is improved, and the industrial economic benefit is improved; in addition, the invention selects the complex enzyme preparation with high directionality, is not influenced by the flocculant, can directly decompose the protein combined with the flocculant into small molecular peptides and amino acids, can be directly applied to animal feeds and organic fertilizers, increases the nitrogen source intake and absorption of animals or plants, and solves the application problem of the protein.

The invention realizes the technical effects through the following technical scheme:

a preparation method for extracting hydrolyzed protein from whey waste liquid specifically comprises the following steps:

(1) flocculation and precipitation: adding a flocculating agent into the whey waste liquid, uniformly stirring, and adjusting the pH value of the whey waste liquid to 5.0-6.0 to continuously precipitate protein;

(2) centrifugal separation: centrifuging the whey waste liquid after flocculation precipitation for 20min at 4000-6000 rpm at 25 ℃;

(3) shearing and emulsifying: adding 3 times of purified water into the centrifuged heavy phase for washing, shearing and emulsifying by using a high-speed shearing emulsifying machine, and then centrifugally separating to separate out the heavy phase and the light phase;

(4) and (3) heating for dissociation: adding 2 times of purified water into the centrifuged heavy phase in the step (3), adjusting the pH value to 6.5, heating the mixture in a pressure tank at 120 ℃ for 30min to denature and dissociate the flocculated protein;

(5) cooling and enzymolysis: after heating, introducing cooling water into the interlayer of the pressure tank to reduce the temperature of the feed liquid to 50-55 ℃, adding a complex enzyme preparation, and performing heat preservation and enzymolysis for 15 hours;

(6) sterilization and enzyme deactivation: after the enzymolysis is finished, sterilizing and inactivating enzyme in a pressure tank at 120 ℃ for 10 min;

(7) centrifugal drying: and cooling the feed liquid, centrifuging, and performing spray drying on the light phase to obtain the final product.

Further, in the step (1), the flocculating agent is one or a mixture of polyaluminium chloride and polyacrylamide.

Preferably, the flocculant in the step (1) is a mixture of polyaluminium chloride and polyacrylamide, and the mass ratio of the flocculant to the flocculant is 5: 1.

Further, the addition amount of the flocculating agent in the step (1) is 3-5 g/L of the whey waste liquid.

Optimally, the addition amount of the flocculating agent in the step (1) is 3g/L of the whey waste liquid.

Further, the addition amount of the complex enzyme preparation in the step (5) is 6-8% of the mass ratio of the feed liquid.

Further, the compound enzyme preparation is a mixture of alkaline protease, compound protease and phytase, and the mass ratio of the compound enzyme preparation to the phytase is 10:2: 1.

Preferably, the alkaline protease and the compound protease are enzyme preparations prepared by Angel yeast production.

Preferably, the light phase after centrifugation in step (3) is recycled to the oligosaccharide production process for oligosaccharide production.

The invention provides a preparation process for extracting hydrolyzed protein from whey waste liquid, which has the following remarkable advantages compared with the prior art:

(1) the invention utilizes the process of compound enzymolysis after protein flocculation to extract the hydrolyzed protein from the whey waste liquid, and solves the problem of low protein extraction rate in the traditional method. The experimental result shows that the protein flocculant is used for precipitating the protein in the whey wastewater, the protein removal rate can reach more than 90 percent, and the final protein utilization rate (hydrolyzed protein/total protein in the whey wastewater) can reach more than 80 percent; the content of amino acid in the obtained product can reach more than 90 percent, and the product is suitable for the absorption and utilization of nitrogen sources by animals and plants;

(2) the invention obviously reduces the production cost of extracting the hydrolyzed protein from the whey waste liquid. According to measurement and calculation, the hydrolyzed protein produced by the method has the advantages that the product cost is greatly reduced to be below 9 yuan/Kg, the average price of the hydrolyzed protein is about 18 yuan/Kg, the product additional value of byproducts of a protein plant is greatly improved, and the economic benefit is increased for enterprises;

(3) the invention has simple process, the existing equipment of the protein factory can meet the production requirement, expensive membrane equipment is not needed to be purchased additionally, and the invention is suitable for continuous production of the factory;

(4) the invention utilizes flocculation and enzymolysis processes to extract the hydrolyzed protein from the whey waste liquid, realizes zero discharge of the waste liquid after the protein is utilized, can effectively reduce the pollution of the whey waste water to the environment, and has obvious environmental protection benefit.

Detailed Description