阅读说明：本技术 一种模拟人体消化道酶解制备蛋白小分子肽的方法 (Method for preparing protein small molecule peptide by simulating human body digestive tract enzymolysis ) 是由 罗伟敏 陈顺钦 于 2020-05-12 设计创作，主要内容包括：本发明公开一种模拟人体消化道酶解制备蛋白小分子肽的方法,其包括将骨头破碎成骨块,蒸煮后干燥粉碎,加入蒸馏水调配至质量分数为20～30％；调节pH值至3.0～5.0,加入木瓜蛋白酶和还原剂,辅以超声波和微波进行预酶解；调节pH值至1.0～4.0,加入胃蛋白酶并辅以超声波进行一次酶解；调节pH值至7.0～8.5,加入糜蛋白酶与胰蛋白酶的混合酶,辅以超声波进行二次酶解；进行脱盐处理；收集多肽液进行喷雾干燥,得到蛋白小分子肽。本发明基于模拟人体消化道中主要的消化蛋白酶类的酶解程序,经预酶解及一次、二次酶解,并辅以超声波-微波,酶解出便于人体直接吸收和利用的蛋白小分子肽类产品。(The invention discloses a method for preparing protein small molecule peptide by simulating human body digestive tract enzymolysis, which comprises the steps of crushing bones into bone blocks, cooking, drying, crushing, adding distilled water and blending until the mass fraction is 20-30%; adjusting the pH value to 3.0-5.0, adding papain and a reducing agent, and performing pre-enzymolysis by using ultrasonic waves and microwaves; adjusting the pH value to 1.0-4.0, adding pepsin and assisting with ultrasonic waves to carry out primary enzymolysis; adjusting the pH value to 7.0-8.5, adding mixed enzyme of chymotrypsin and trypsin, and performing secondary enzymolysis with ultrasonic waves; carrying out desalination treatment; and collecting the polypeptide liquid, and performing spray drying to obtain the protein small molecular peptide. The invention is based on the enzymolysis program of the main digestive protease in the simulated human digestive tract, and carries out enzymolysis, primary enzymolysis and secondary enzymolysis, and is assisted by ultrasonic waves-microwaves to carry out enzymolysis to obtain the protein micromolecule peptide product which is convenient for the human body to directly absorb and utilize.)

1. A method for preparing protein small molecule peptide by simulating human body digestive tract enzymolysis is characterized by comprising the following steps:

step 1, crushing cleaned fresh animal bones into bone blocks, cooking the bone blocks by boiling water, drying and crushing the bone blocks to obtain dry bone powder, and adding distilled water to prepare bone slurry liquid with the mass fraction of 20-30%;

step 2, adjusting the pH value of the bone slurry to 3.0-5.0, adding papain and a reducing agent, and performing pre-enzymolysis by using ultrasonic waves and microwaves to obtain pre-enzymolysis liquid;

step 3, filtering and centrifuging the pre-enzymolysis liquid prepared in the step 2 to obtain crude protein hydrolysate;

step 4, adjusting the pH value of the crude protein hydrolysate to 1.0-4.0, adding pepsin and assisting ultrasonic wave to carry out primary enzymolysis to obtain primary enzymolysis liquid; then adjusting the pH value of the primary enzymolysis liquid to 7.0-8.5, adding mixed enzyme of chymotrypsin and trypsin, and performing secondary enzymolysis with ultrasonic waves; after the secondary enzymolysis is finished, adjusting the pH value to be neutral to obtain secondary enzymolysis liquid;

step 5, adopting a mixed bed consisting of strong acid type cation exchange resin and weak base type anion exchange resin to desalt the secondary enzymolysis liquid to obtain a desalted hydrolysis liquid;

and 6, intercepting and separating the desalted hydrolysate by using an ultrafiltration membrane, collecting polypeptide liquid, and performing spray drying to obtain the protein micromolecule peptide.

2. The method for preparing a protein small-molecule peptide by simulating the enzymatic hydrolysis of the human digestive tract according to claim 1, wherein the specific steps of the step 2 comprise:

step 2-1, adjusting the pH value of the bone slurry to 3.0-5.0, adding papain in an amount which is 0.5 percent of the mass of the dry bone powder, and simultaneously adding a reducing agent, wherein the mass fraction ratio of the papain to the reducing agent is 1: 0.2 to 1;

and 2-2, irradiating for 5min at 30-40 ℃ by using a microwave with the power of 200W, and simultaneously performing pre-enzymolysis on the bone slurry for 20-40 min by using ultrasonic waves with the power of 100-300W and the frequency of 40-60 kHz to obtain pre-enzymolysis liquid, wherein the ultrasonic waves stop for 20-40 s at intervals of 10 s.

3. The method for preparing a protein small-molecule peptide by simulating the enzymatic hydrolysis of the human digestive tract according to claim 2, wherein the specific steps of the step 4 comprise:

step 4-1, adjusting the pH value of the crude protein hydrolysate to 1.0-4.0, adding pepsin accounting for 0.1-0.2% of the mass of the dry bone meal, and performing enzymolysis for 30-50 min at 40-50 ℃ with the assistance of ultrasonic waves to obtain a primary hydrolysate;

step 4-2, adjusting the pH value of the primary enzymolysis liquid to 7.0-8.5, adding a mixed enzyme of chymotrypsin and trypsin according to 0.1-0.2% of the mass of the dry bone meal, and performing enzymolysis for 30-50 min at 30-40 ℃ by using ultrasonic waves as an auxiliary material to obtain a secondary enzymolysis liquid, wherein the mass ratio of the chymotrypsin to the trypsin is 1: 1;

and 4-3, after finishing the secondary enzymolysis, inactivating the enzyme for 10min at 90 ℃, and adjusting the pH value to be neutral to obtain secondary enzymolysis liquid.

4. The method for preparing protein small-molecule peptide by simulating human digestive tract enzymolysis according to claim 3, wherein the conditions of the ultrasonic-assisted enzymolysis in the step 4-1 and the step 4-2 are as follows: the power is 100-300W, the frequency is 40-60 kHz, and the ultrasonic wave stops intermittently for 20-40 s every 10 s.

5. The method for preparing a small-molecule peptide by simulating the enzymatic hydrolysis of the digestive tract of a human body according to claim 4, wherein in the step 4-2, the enzyme activities of the pepsin, the chymotrypsin and the trypsin are all 20 ten thousand U/g.

6. The method for preparing a protein small molecule peptide by simulating the enzymatic hydrolysis of the digestive tract of a human body according to claim 2, wherein the reducing agent in the step 2-1 is ascorbic acid or erythorbic acid, and the addition amount of the reducing agent is 25mg to 125mg per 10 ten thousand U enzyme activity of the papain.

7. The method for preparing protein small-molecule peptide by simulating human digestive tract enzymolysis according to claim 6, wherein the enzyme activity of the papain is 80 ten thousand U/g.

8. The method for preparing protein small-molecule peptide by simulating human digestive tract enzymolysis according to claim 3, wherein the specific steps of the step 1 comprise:

step 1-1, crushing cleaned fresh animal bones into bone blocks, adding boiling water according to a material-liquid ratio of 1: 2-3, and cooking for 40-80 min;

step 1-2, removing surface grease of the cooking liquor, draining the bone blocks, and drying at 80-90 ℃ until the water content is less than 5%;

step 1-3, carrying out coarse crushing and ultrafine crushing on the bone blocks dried in the step 1-2 in sequence until the particle size is smaller than 200 meshes to obtain dry bone powder;

and step 1-4, adding distilled water into the dried bone powder obtained in the step 1-3 to prepare bone slurry liquid with the mass fraction of 20-30%.

9. The method for preparing a small-molecule peptide by simulating the enzymatic hydrolysis of the human digestive tract according to claim 8, wherein the specific steps of the step 6 comprise: and centrifuging the desalted hydrolysate for 20min at the rotating speed of 4000r/min, taking supernatant, performing interception and separation by using an ultrafiltration membrane, collecting polypeptide liquid, and performing spray drying to obtain the protein small molecular peptide.

10. The method for preparing a small protein molecule peptide by simulating the enzymatic hydrolysis of the human digestive tract according to claim 9, wherein the spray drying conditions in the step 6 are as follows: the inlet temperature is 180 ℃ and the outlet temperature is 120 ℃.

Technical Field

The invention relates to the field of production of protein small molecule peptides, in particular to a method for preparing protein small molecule peptides by simulating human digestive tract enzymolysis.

Background

Animal bones are rich in nutrients, including abundant proteins, fats and calcium. As the first major world meat food, China produces more than 1500 million tons of bones every year. Therefore, the full utilization of animal bones to vigorously develop bone foods becomes a primary problem in the food industry, particularly in meat processing enterprises.

In recent years, scientific researches believe that not all proteins can be absorbed and utilized by human bodies, the proteins absorbed by the human bodies are mainly absorbed in the form of peptides, and after the proteins are absorbed into the human bodies, specific and complicated protein enzymolysis procedures are needed through the digestive tracts of the human bodies to form specific protein small molecular peptides which can be absorbed and utilized by the human bodies, so that the physiological functions of various systems and cells in the human bodies are adjusted.

At present, various technologies of catalyzing animal-derived bones by using biological enzymes are widely developed, wherein the traditional preparation technology comprises the steps of cooking fresh animal bones at high temperature and high pressure, removing oil and degreasing, adjusting the pH value by using alkali or acid, adding protease to carry out enzymolysis on proteins, and obtaining micromolecular polypeptides after the enzymolysis. It is obvious that at present, the single enzyme method is mainly adopted for hydrolyzing fresh animal bones, the polypeptide products produced by hydrolyzing single enzymes or non-human digestive tract enzymes are adopted, the enzymolysis time is long, the enzymolysis degree and the oligopeptide content are low, and only by simple stirring and mixing steps, the full and uniform combination of the enzymes and the proteins is difficult to ensure, the enzymolysis effect and the efficiency are poor, the ratio of the polypeptides with high relative molecular weight in the enzymolysis products is high, the polypeptide is not suitable for being directly absorbed and utilized by human bodies, and the immunity of the human bodies cannot be improved.

Therefore, how to develop an enzymolysis procedure based on the simulation of the main digestive proteases in the human digestive tract to enzymolyze small molecule peptide products which are convenient for the human body to directly absorb and utilize becomes a major technical problem in the current food industry under the condition of promoting the proteins and the enzymes to be fully and uniformly combined.

Disclosure of Invention

In order to overcome the technical problems, the invention discloses a method for preparing protein small-molecule peptide by simulating human digestive tract enzymolysis.

The technical scheme adopted by the invention for realizing the purpose is as follows:

a method for preparing protein small molecule peptide by simulating human body digestive tract enzymolysis comprises the following steps:

step 1, crushing cleaned fresh animal bones into bone blocks, cooking the bone blocks by boiling water, drying and crushing the bone blocks to obtain dry bone powder, and adding distilled water to prepare bone slurry liquid with the mass fraction of 20-30%;

step 2, adjusting the pH value of the bone slurry to 3.0-5.0, adding papain and a reducing agent, and performing pre-enzymolysis by using ultrasonic waves and microwaves to obtain pre-enzymolysis liquid;

step 3, filtering and centrifuging the pre-enzymolysis liquid prepared in the step 2 to obtain crude protein hydrolysate;

step 4, adjusting the pH value of the crude protein hydrolysate to 1.0-4.0, adding pepsin and assisting ultrasonic wave to carry out primary enzymolysis to obtain primary enzymolysis liquid; then adjusting the pH value of the primary enzymolysis liquid to 7.0-8.5, adding mixed enzyme of chymotrypsin and trypsin, and performing secondary enzymolysis with ultrasonic waves; after the secondary enzymolysis is finished, adjusting the pH value to be neutral to obtain secondary enzymolysis liquid;

step 5, adopting a mixed bed consisting of strong acid type cation exchange resin and weak base type anion exchange resin to desalt the secondary enzymolysis liquid to obtain a desalted hydrolysis liquid;

and 6, intercepting and separating the desalted hydrolysate by using an ultrafiltration membrane, collecting polypeptide liquid, and performing spray drying to obtain the protein micromolecule peptide.

The method for preparing the protein small molecule peptide by simulating the human digestive tract enzymolysis comprises the following specific steps of step 2:

step 2-1, adjusting the pH value of the bone slurry to 3.0-5.0, adding papain in an amount which is 0.5 percent of the mass of the dry bone powder, and simultaneously adding a reducing agent, wherein the mass fraction ratio of the papain to the reducing agent is 1: 0.2 to 1;

and 2-2, irradiating for 5min at 30-40 ℃ by using a microwave with the power of 200W, and simultaneously performing pre-enzymolysis on the bone slurry for 20-40 min by using ultrasonic waves with the power of 100-300W and the frequency of 40-60 kHz to obtain pre-enzymolysis liquid, wherein the ultrasonic waves stop for 20-40 s at intervals of 10 s.

The method for preparing the protein small molecule peptide by simulating the human digestive tract enzymolysis comprises the following specific steps of step 4:

step 4-1, adjusting the pH value of the crude protein hydrolysate to 1.0-4.0, adding pepsin accounting for 0.1-0.2% of the mass of the dry bone meal, and performing enzymolysis for 30-50 min at 40-50 ℃ with the assistance of ultrasonic waves to obtain a primary hydrolysate;

step 4-2, adjusting the pH value of the primary enzymolysis liquid to 7.0-8.5, adding a mixed enzyme of chymotrypsin and trypsin according to 0.1-0.2% of the mass of the dry bone meal, and performing enzymolysis for 30-50 min at 30-40 ℃ by using ultrasonic waves as an auxiliary material to obtain a secondary enzymolysis liquid, wherein the mass ratio of the chymotrypsin to the trypsin is 1: 1;

and 4-3, after finishing the secondary enzymolysis, inactivating the enzyme for 10min at 90 ℃, and adjusting the pH value to be neutral to obtain secondary enzymolysis liquid.

In the method for preparing the protein small molecule peptide by simulating human digestive tract enzymolysis, the conditions of ultrasonic-assisted enzymolysis in the step 4-1 and the step 4-2 are as follows: the power is 100-300W, the frequency is 40-60 kHz, and the ultrasonic wave stops intermittently for 20-40 s every 10 s.

In the method for preparing the protein small molecule peptide by simulating human digestive tract enzymolysis, in the step 4-2, the enzyme activities of the pepsin, the chymotrypsin and the trypsin are all 20 ten thousand U/g.

In the method for preparing the protein small molecule peptide by simulating human digestive tract enzymatic hydrolysis, the reducing agent in the step 2-1 is ascorbic acid or erythorbic acid, and the addition amount of the reducing agent is 25-125 mg per 10 ten thousand U of enzyme activity of the papain.

The method for preparing the protein small molecule peptide by simulating human digestive tract enzymolysis, wherein the enzyme activity of the papain is 80 ten thousand U/g.

The method for preparing the protein small molecule peptide by simulating the human digestive tract enzymolysis comprises the following specific steps of step 1:

step 1-1, crushing cleaned fresh animal bones into bone blocks, adding boiling water according to a material-liquid ratio of 1: 2-3, and cooking for 40-80 min;

step 1-2, removing surface grease of the cooking liquor, draining the bone blocks, and drying at 80-90 ℃ until the water content is less than 5%;

step 1-3, carrying out coarse crushing and ultrafine crushing on the bone blocks dried in the step 1-2 in sequence until the particle size is smaller than 200 meshes to obtain dry bone powder;

and step 1-4, adding distilled water into the dried bone powder obtained in the step 1-3 to prepare bone slurry liquid with the mass fraction of 20-30%.

The method for preparing the protein small molecule peptide by simulating the human digestive tract enzymolysis comprises the following specific steps of step 6: and centrifuging the desalted hydrolysate for 20min at the rotating speed of 4000r/min, taking supernatant, performing interception separation by using an ultrafiltration membrane, collecting polypeptide liquid with the molecular weight of less than 1kDal, and performing spray drying to obtain the protein micromolecule peptide.

The method for preparing the protein small molecule peptide by simulating human digestive tract enzymolysis comprises the following steps of (1): the inlet temperature is 180 ℃ and the outlet temperature is 120 ℃.

The invention has the beneficial effects that:

(1) according to the invention, under an acidic condition, papain and a reducing agent are combined, and microwave-ultrasonic waves are simultaneously used for enzymolysis, so that the fresh animal bone and bone marrow protein are subjected to pre-enzymolysis, and the polypeptide of a specific small molecule peptide product is conveniently formed in the subsequent enzymolysis process, the enzymolysis efficiency is effectively improved, and the enzymolysis time is shortened, wherein the ultrasonic waves and the microwaves cooperate to promote the protein and enzymes to be fully and uniformly combined, and also promote the collision of the reducing agent and an enzymatic center disulfide bond, so that the enzymolysis effect and efficiency are further improved, the activity and the enzymolysis efficiency of the papain are greatly improved by the reducing agent, the cost of the papain is low, and the obtaining way is convenient;

(2) according to the invention, pepsin, chymotrypsin and trypsin are sequentially adopted for carrying out primary and secondary enzymolysis to simulate the enzymolysis program of main digestive proteases in the human digestive tract, and the polypeptide is further subjected to enzymolysis to form protein small molecular peptides similar to the human digestive tract enzymatic hydrolysate according to different enzymes, so that the protein small molecular peptides can be directly absorbed and utilized by the human body; in addition, ultrasonic waves are supplemented in the primary and secondary enzymolysis processes, so that the polypeptide is promoted to be fully and uniformly combined with enzymes, and the enzymolysis effect and efficiency are further improved;

(3) according to the invention, the pig, cow or sheep bones are adopted, and the bone powder with small particle size is obtained by sequentially carrying out coarse crushing and ultrafine crushing, so that the bone powder is conveniently and fully contacted with enzyme in the subsequent enzymolysis process, and the enzymolysis efficiency is further improved;

(4) the mixed bed composed of strong acid type cation exchange resin and weak base type anion exchange resin is adopted for desalination treatment, the desalination efficiency is high, and the desalted low-salt end product is beneficial to absorption and supplement of human body;

(5) the polypeptide yield of less than 1kDal in the prepared protein micromolecule peptide reaches more than 85 percent, compared with a comparative example, the cell transfer and immunoregulation data are obviously improved, the content of peptide nitrogen in an absorption product of a simulated cell peptide transfer system is about 1.93 plus or minus 0.16mmol/L Gly, the content of interleukin-6 (IL-6) is about 361.4 plus or minus 29.8pg/mL, the phagocytosis index is about 8.6 plus or minus 0.6, and the antibody product number is about 67 plus or minus 7.7, therefore, the enzymolysis preparation method has high enzymolysis effect and efficiency, the protein micromolecule peptide can be directly absorbed and utilized, has potential physiological activity, has important significance in the aspect of body health protection, does not influence immune organs of a body, also has obvious function of regulating the immune function, realizes that the small molecule peptide product can be directly absorbed and utilized by the body, and is suitable for the taking needs of different crowds, so as to improve the immunity.

Detailed Description

The present invention is further illustrated by the following specific examples, which are intended to facilitate the understanding and appreciation of the technical solutions of the present invention, rather than to limit the invention thereto.

The invention provides a method for preparing protein small molecule peptide by simulating human body digestive tract enzymolysis, which comprises the following steps:

step 1, crushing cleaned fresh animal bones into bone blocks, cooking the bone blocks by boiling water, drying and crushing the bone blocks to obtain dry bone powder, and adding distilled water to prepare bone slurry liquid with the mass fraction of 20-30%;

step 2, adjusting the pH value of the bone slurry to 3.0-5.0, adding papain and a reducing agent, and performing pre-enzymolysis by using ultrasonic waves and microwaves to obtain pre-enzymolysis liquid;

step 3, filtering and centrifuging the pre-enzymolysis liquid prepared in the step 2 to obtain crude protein hydrolysate;

step 4, adjusting the pH value of the crude protein hydrolysate to 1.0-4.0, adding pepsin and assisting ultrasonic wave to carry out primary enzymolysis to obtain primary enzymolysis liquid; then adjusting the pH value of the primary enzymolysis liquid to 7.0-8.5, adding mixed enzyme of chymotrypsin and trypsin, and performing secondary enzymolysis with ultrasonic waves; after the secondary enzymolysis is finished, adjusting the pH value to be neutral to obtain secondary enzymolysis liquid;

step 5, adopting a mixed bed consisting of strong acid type cation exchange resin and weak base type anion exchange resin to desalt the secondary enzymolysis liquid to obtain a desalted hydrolysis liquid; the desalting efficiency is high, and the desalted low-salt end product is beneficial to human body absorption and supplement;

and 6, intercepting and separating the desalted hydrolysate by using an ultrafiltration membrane, collecting polypeptide liquid, and performing spray drying to obtain the protein micromolecule peptide.

Preferably, the specific steps of step 2 include:

step 2-1, adjusting the pH value of the bone slurry to 3.0-5.0, adding papain in an amount which is 0.5 percent of the mass of the dry bone powder, and simultaneously adding a reducing agent, wherein the mass fraction ratio of the papain to the reducing agent is 1: 0.2 to 1; preferably, the enzyme activity of the papain is 80 ten thousand U/g, the reducing agent is ascorbic acid or erythorbic acid, and the addition amount of the reducing agent is 25-125 mg per 10 ten thousand U of the enzyme activity of the papain;

step 2-2, irradiating for 5min at 30-40 ℃ by aid of microwaves with the power of 200W, and simultaneously performing pre-enzymolysis on the bone slurry for 20-40 min by aid of ultrasonic waves with the power of 100-300W and the frequency of 40-60 kHz to obtain pre-enzymolysis liquid, wherein the ultrasonic waves stop for 20-40 s at intervals of 10 s; under the acidic condition, papain and a reducing agent are combined, and microwave-ultrasonic wave is used for enzymolysis, so that the fresh animal bone and bone marrow protein are subjected to pre-enzymolysis, polypeptide of a specific small molecular peptide product is formed in the subsequent enzymolysis process, the enzymolysis efficiency is effectively improved, and the enzymolysis time is shortened.

Preferably, the specific steps of step 4 include:

step 4-1, adjusting the pH value of the crude protein hydrolysate to 1.0-4.0, adding pepsin accounting for 0.1-0.2% of the mass of the dry bone meal, and performing enzymolysis for 30-50 min at 40-50 ℃ with the assistance of ultrasonic waves to obtain a primary hydrolysate;

step 4-2, adjusting the pH value of the primary enzymolysis liquid to 7.0-8.5, adding a mixed enzyme of chymotrypsin and trypsin according to 0.1-0.2% of the mass of the dry bone meal, and performing enzymolysis for 30-50 min at 30-40 ℃ by using ultrasonic waves as an auxiliary material to obtain a secondary enzymolysis liquid, wherein the mass ratio of the chymotrypsin to the trypsin is 1: 1; preferably, the enzyme activities of the pepsin, the chymotrypsin and the trypsin are all 20 ten thousand U/g;

step 4-3, after finishing the secondary enzymolysis, inactivating the enzyme for 10min at 90 ℃, and adjusting the pH value to be neutral to obtain secondary enzymolysis liquid;

preferably, the conditions of the ultrasonic-assisted enzymolysis in the step 4-1 and the step 4-2 are as follows: the power is 100-300W, the frequency is 40-60 kHz, and the ultrasonic stops for 20-40 s at intervals of 10s every time; pepsin, chymotrypsin and trypsin are sequentially adopted for primary and secondary enzymolysis to simulate the enzymolysis program of main digestive proteases in the human digestive tract, and the polypeptide is further subjected to enzymolysis to form a small molecular peptide product similar to the human digestive tract enzymolysis product according to different enzymes with different enzyme digestion sites, so that the small molecular peptide product can be directly absorbed and utilized by the human body, and is suitable for the taking requirements of different crowds to improve the immunity; in addition, ultrasonic waves are supplemented in the primary and secondary enzymolysis processes, so that the polypeptide and enzymes are promoted to be fully and uniformly combined, and the enzymolysis effect and efficiency are further improved.

Preferably, the specific steps of step 1 include:

step 1-1, crushing cleaned fresh animal bones into bone blocks, adding boiling water according to a feed-liquid ratio of 1: 2-3, and stewing for 40-80min, wherein the fresh animal bones are preferably pig, cattle or sheep bones;

step 1-2, removing surface grease of the cooking liquor, draining the bone blocks, and drying at 80-90 ℃ until the water content is less than 5%;

1-3, performing coarse crushing and ultrafine crushing on the bone blocks dried in the step 1-2 in sequence until the particle size is smaller than 200 meshes to obtain dried bone powder, wherein the crushed bone powder with small particle size is convenient to fully contact with enzyme in the subsequent enzymolysis process, so that the enzymolysis efficiency is improved;

and step 1-4, adding distilled water into the dried bone powder obtained in the step 1-3 to prepare bone slurry liquid with the mass fraction of 20-30%.

Further, the specific steps of step 6 include: centrifuging the desalted hydrolysate for 20min at the rotating speed of 4000r/min, taking supernatant, performing interception separation by using an ultrafiltration membrane, collecting polypeptide liquid with the molecular weight of less than 1kDal, and performing spray drying to obtain protein micromolecule peptide; preferably, the spray drying conditions are: the inlet temperature is 180 ℃ and the outlet temperature is 120 ℃.

Now, the following examples are described in detail according to the preparation method of the present invention, and corresponding comparative examples are made according to the examples to further understand and grasp the technical scheme of the present invention.