阅读说明：本技术 一种胶原蛋白肽生产过程中蛋白提取工艺 (Protein extraction process in production process of collagen peptide ) 是由 不公告发明人 于 2021-08-10 设计创作，主要内容包括：本发明公开了一种胶原蛋白肽生产过程中蛋白提取工艺,属于食品工业技术领域。它包括以下步骤：(1)鱼皮预处理：购买新鲜鱼,取鱼皮,并清洗干净,直至鱼皮表面的鱼鳞去除干净；(2)碱液处理：将步骤(1)中预处理后的鱼皮,转移到反应釜中,并添加碱液,处理后添加碳酸氢钠溶液处理,最后用去离子水清洗干净；(3)酶解处理：将步骤(2)中碱液处理后的鱼皮,转移到料液槽中,并添加复合酶液,处理后沥干即可；(4)离心处理：将步骤(3)中酶解处理后的鱼皮,转移到离心机中,离心后取上清液；(5)超滤处理：将步骤(4)中离心处理的上清液,转移到超滤膜进行过滤,最后进行真空冷冻干燥。制备得到的胶原蛋白肽可满足市场需求。(The invention discloses a protein extraction process in a collagen peptide production process, and belongs to the technical field of food industry. It comprises the following steps: (1) pretreatment of fish skin: purchasing fresh fish, taking fish skin, and cleaning until the scales on the surface of the fish skin are removed; (2) alkali liquor treatment: transferring the fish skin pretreated in the step (1) into a reaction kettle, adding alkali liquor, adding a sodium bicarbonate solution for treatment, and finally cleaning with deionized water; (3) and (3) enzymolysis treatment: transferring the fish skin treated by the alkali liquor in the step (2) into a feed liquor tank, adding a compound enzyme solution, and draining after treatment; (4) and (3) centrifugal treatment: transferring the fish skin subjected to enzymolysis treatment in the step (3) into a centrifugal machine, and taking supernatant after centrifugation; (5) and (3) ultrafiltration treatment: transferring the supernatant subjected to the centrifugal treatment in the step (4) to an ultrafiltration membrane for filtration, and finally performing vacuum freeze drying. The prepared collagen peptide can meet the market demand.)

1. A protein extraction process in the production process of collagen peptide is characterized in that:

the method comprises the following steps:

(1) pretreatment of fish skin: purchasing fresh fish, taking fish skin, and cleaning until the scales on the surface of the fish skin are removed;

(2) alkali liquor treatment: transferring the fish skin pretreated in the step (1) into a reaction kettle, adding alkali liquor, adding a sodium bicarbonate solution for treatment, and finally cleaning with deionized water;

(3) and (3) enzymolysis treatment: transferring the fish skin treated by the alkali liquor in the step (2) into a feed liquor tank, adding a compound enzyme solution, and draining after treatment;

(4) and (3) centrifugal treatment: transferring the fish skin subjected to enzymolysis treatment in the step (3) into a centrifugal machine, and taking supernatant after centrifugation;

(5) and (3) ultrafiltration treatment: transferring the supernatant subjected to the centrifugal treatment in the step (4) to an ultrafiltration membrane for filtration, and finally performing vacuum freeze drying.

2. The process for extracting protein during the production of collagen peptide according to claim 1, wherein:

the variety of the fresh fish in the step (1) is silver carp.

3. The process for extracting protein during the production of collagen peptide according to claim 1, wherein:

the mass ratio of the alkali liquor to the fish skin in the step (2) is 20: 1.

4. the process for extracting protein during the production of collagen peptide according to claim 3, wherein:

the temperature of the alkali liquor in the step (2) is 50 ℃;

the mass ratio of the sodium bicarbonate to the fish skin in the step (2) is 5: 1.

5. the process for extracting protein during the production of collagen peptide according to claim 1, wherein:

the compound enzyme solution in the step (3) comprises neutral protease, papain and water;

the mass ratio of the neutral protease to the papain to the water is 1: 5: 100.

6. the process for extracting protein during the production of collagen peptide according to claim 5, wherein:

the temperature of the complex enzyme solution in the step (3) is 37 ℃.

7. The process for extracting protein during the production of collagen peptide according to claim 1, wherein:

the centrifugal force of the centrifuge in the step (4) was 12000 g.

8. The process for extracting protein during the production of collagen peptide according to claim 1, wherein:

the temperature of the centrifuge in the step (4) is 4 ℃.

9. The process for extracting protein during the production of collagen peptide according to claim 1, wherein:

the aperture of the ultrafiltration membrane in the step (5) is 1000 daltons.

Technical Field

The invention belongs to the technical field of food industry, and particularly relates to a protein extraction process in a collagen peptide production process.

Background

Collagen is an extremely important structural protein in connective tissues, is the most abundant and widely distributed protein in animals, accounts for about 25-30% of the total amount of the protein in the bodies, and the collagen with overlarge molecular weight has low absorption and utilization rate in human bodies, and can be effectively absorbed by the human bodies only by degrading collagen peptide with the molecular weight ranging from 200-10000 Da through a biological technology. The research proves that the average molecular weight of the protein hydrolysate is one of the most important factors for determining the biological properties of the protein hydrolysate, and the physicochemical and functional characteristics of the protein peptide component are related to the molecular weight.

The application of extracting collagen peptide from pigskin and cow leather is wide, but the fishskin has low price, rich sources and easy extraction, and has no risk of epidemic diseases of terrestrial animals. China is the largest freshwater fish breeding country in the world, with the rapid development of freshwater fish processing industry, a large amount of wastes such as fish skin and fish scales are generated in the processing process, if the wastes are not fully utilized, the environment is polluted, and simultaneously, the wastes on resources are greatly wasted, so that the research on extracting collagen peptide from fish leftovers has far-reaching significance.

Chinese patent application publication No. CN102621213A discloses a method for evaluating the thermal denaturation degree of macromolecular collagen by a pepsin method, which comprises the steps of soaking and dissolving raw materials, heating and carrying out enzymolysis to obtain complete triple-helix collagen with the molecular weight of more than 30 ten thousand Da, and evaluating the thermal denaturation degree of the collagen. Chinese patent CN 102676620B discloses a preparation method of high molecular weight squid skin collagen, which selects ultrafiltration membrane with molecular weight cutoff of 100kda to carry out ultrafiltration on enzymolysis liquid, to obtain macromolecular collagen peptide and recover small molecular collagen peptide. Chinese patent application publication No. 103627763A discloses a method for classifying the molecular weight of collagen peptide of anglerfish skin, wherein the anglerfish skin enzymolysis liquid is passed through a first-level plate-type ultrafiltration membrane to intercept collagen peptide with molecular weight more than 10000 Dalton, then passed through a second-level roll-type ultrafiltration membrane to intercept collagen peptide with molecular weight more than 2000 Dalton, and then passed through a roll-type nanofiltration membrane to intercept collagen peptide with molecular weight more than 200 Dalton. The collagen peptides prepared by the method have far-ranging molecular weight difference and non-concentrated distribution, and finally the collagen peptides in different molecular weight sections are obtained by ultrafiltration grading, so that the process is complex and the cost is high.

Disclosure of Invention

1. Problems to be solved

Aiming at the problems in the prior art, the invention provides a protein extraction process in the production process of collagen peptide, which is simple in process, and particularly, the prepared protein meets the use requirement.

2. Technical scheme

In order to solve the above problems, the present invention adopts the following technical solutions.

A protein extraction process in the production process of collagen peptide comprises the following steps:

(1) pretreatment of fish skin: purchasing fresh fish, taking fish skin, and cleaning until the scales on the surface of the fish skin are removed;

(2) alkali liquor treatment: transferring the fish skin pretreated in the step (1) into a reaction kettle, adding alkali liquor, adding a sodium bicarbonate solution for treatment, and finally cleaning with deionized water;

(3) and (3) enzymolysis treatment: transferring the fish skin treated by the alkali liquor in the step (2) into a feed liquor tank, adding a compound enzyme solution, and draining after treatment;

(4) and (3) centrifugal treatment: transferring the fish skin subjected to enzymolysis treatment in the step (3) into a centrifugal machine, and taking supernatant after centrifugation;

(5) and (3) ultrafiltration treatment: transferring the supernatant subjected to the centrifugal treatment in the step (4) to an ultrafiltration membrane for filtration, and finally performing vacuum freeze drying.

In the protein extraction process in the production process of the collagen peptide, the variety of the fresh fish in the step (1) is silver carp.

In the protein extraction process in the production process of the collagen peptide, the mass ratio of the alkali liquor to the fish skin in the step (2) is 20: 1.

in the protein extraction process in the production process of the collagen peptide, the temperature of the alkali liquor in the step (2) is 50 ℃;

the mass ratio of the sodium bicarbonate to the fish skin in the step (2) is 5: 1.

in the protein extraction process in the production process of the collagen peptide, the compound enzyme solution in the step (3) comprises neutral protease, papain and water;

the mass ratio of the neutral protease to the papain to the water is 1: 5: 100.

in the protein extraction process in the production process of the collagen peptide, the temperature of the compound enzyme liquid in the step (3) is 37 ℃.

In the protein extraction process in the production process of the collagen peptide, the centrifugal force of the centrifugal machine in the step (4) is 12000 g.

In the protein extraction process in the production process of the collagen peptide, the temperature of the centrifuge in the step (4) is 4 ℃.

In the protein extraction process in the production process of the collagen peptide, the aperture of the ultrafiltration membrane in the step (5) is 1000 daltons.

3. Advantageous effects

Compared with the prior art, the invention has the beneficial effects that:

the collagen peptide obtained by the extraction process is mainly used in small scale, and the purity can meet the market demand. Compared with the traditional technology, the method has the advantages that the chub skin is fully utilized, the proportional relation of the enzymolysis treatment liquid is reasonably set, effective mixing among various enzymes is set, and the alkali liquor treatment method is optimized, so that the prepared protein meets the requirements.

Detailed Description

The invention is further described with reference to specific examples.

Example 1

Best mode for carrying out the invention

The protein extraction process in the production process of the collagen peptide comprises the following steps:

(1) pretreatment of fish skin: purchasing fresh fish, taking fish skin, and cleaning until the scales on the surface of the fish skin are removed;

(2) alkali liquor treatment: transferring the fish skin pretreated in the step (1) into a reaction kettle, adding alkali liquor, adding a sodium bicarbonate solution for treatment, and finally cleaning with deionized water;

(3) and (3) enzymolysis treatment: transferring the fish skin treated by the alkali liquor in the step (2) into a feed liquor tank, adding a compound enzyme solution, and draining after treatment;

(4) and (3) centrifugal treatment: transferring the fish skin subjected to enzymolysis treatment in the step (3) into a centrifugal machine, and taking supernatant after centrifugation;

(5) and (3) ultrafiltration treatment: transferring the supernatant subjected to the centrifugal treatment in the step (4) to an ultrafiltration membrane for filtration, and finally performing vacuum freeze drying.

In the protein extraction process in the production process of the collagen peptide, the variety of the fresh fish in the step (1) is silver carp.

In the protein extraction process in the production process of the collagen peptide, the mass ratio of the alkali liquor to the fish skin in the step (2) is 20: 1.

in the protein extraction process in the production process of the collagen peptide, the temperature of the alkali liquor in the step (2) is 50 ℃;

the mass ratio of the sodium bicarbonate to the fish skin in the step (2) is 5: 1.

in the protein extraction process in the production process of the collagen peptide, the compound enzyme solution in the step (3) comprises neutral protease, papain and water;

the mass ratio of the neutral protease to the papain to the water is 1: 5: 100.

in the protein extraction process in the production process of the collagen peptide, the temperature of the compound enzyme liquid in the step (3) is 37 ℃.

In the protein extraction process in the production process of the collagen peptide, the centrifugal force of the centrifugal machine in the step (4) is 12000 g.

In the protein extraction process in the production process of the collagen peptide, the temperature of the centrifuge in the step (4) is 4 ℃.

In the protein extraction process in the production process of the collagen peptide, the aperture of the ultrafiltration membrane in the step (5) is 1000 daltons.

Comparative example 1

The protein extraction process in the production process of the collagen peptide comprises the following steps:

(1) pretreatment of fish skin: purchasing fresh fish, taking fish skin, and cleaning until the scales on the surface of the fish skin are removed;

(2) alkali liquor treatment: transferring the fish skin pretreated in the step (1) into a reaction kettle, adding alkali liquor, adding a sodium bicarbonate solution for treatment, and finally cleaning with deionized water;

(3) and (3) enzymolysis treatment: transferring the fish skin treated by the alkali liquor in the step (2) into a feed liquor tank, adding a compound enzyme solution, and draining after treatment;

(4) and (3) centrifugal treatment: transferring the fish skin subjected to enzymolysis treatment in the step (3) into a centrifugal machine, and taking supernatant after centrifugation;

(5) and (3) ultrafiltration treatment: transferring the supernatant subjected to the centrifugal treatment in the step (4) to an ultrafiltration membrane for filtration, and finally performing vacuum freeze drying.

In the protein extraction process in the production process of the collagen peptide, the variety of the fresh fish in the step (1) is silver carp.

In the protein extraction process in the production process of the collagen peptide, the mass ratio of the alkali liquor to the fish skin in the step (2) is 20: 1.

in the protein extraction process in the production process of the collagen peptide, the temperature of the alkali liquor in the step (2) is 50 ℃;

the mass ratio of the sodium bicarbonate to the fish skin in the step (2) is 5: 1.

in the protein extraction process in the production process of the collagen peptide, the compound enzyme solution in the step (3) comprises neutral protease, papain and water;

the mass ratio of the neutral protease to the papain to the water is 5: 5: 100.

in the protein extraction process in the production process of the collagen peptide, the temperature of the compound enzyme liquid in the step (3) is 37 ℃.

In the protein extraction process in the production process of the collagen peptide, the centrifugal force of the centrifugal machine in the step (4) is 12000 g.

In the protein extraction process in the production process of the collagen peptide, the temperature of the centrifuge in the step (4) is 4 ℃.

In the protein extraction process in the production process of the collagen peptide, the aperture of the ultrafiltration membrane in the step (5) is 1000 daltons.

Comparative example 2

The protein extraction process in the production process of the collagen peptide comprises the following steps:

(1) pretreatment of fish skin: purchasing fresh fish, taking fish skin, and cleaning until the scales on the surface of the fish skin are removed;

(2) alkali liquor treatment: transferring the fish skin pretreated in the step (1) into a reaction kettle, adding alkali liquor, adding a sodium bicarbonate solution for treatment, and finally cleaning with deionized water;

(3) and (3) enzymolysis treatment: transferring the fish skin treated by the alkali liquor in the step (2) into a feed liquor tank, adding a compound enzyme solution, and draining after treatment;

(4) and (3) centrifugal treatment: transferring the fish skin subjected to enzymolysis treatment in the step (3) into a centrifugal machine, and taking supernatant after centrifugation;

(5) and (3) ultrafiltration treatment: transferring the supernatant subjected to the centrifugal treatment in the step (4) to an ultrafiltration membrane for filtration, and finally performing vacuum freeze drying.

In the protein extraction process in the production process of the collagen peptide, the variety of the fresh fish in the step (1) is silver carp.

In the protein extraction process in the production process of the collagen peptide, the mass ratio of the alkali liquor to the fish skin in the step (2) is 20: 1.

in the protein extraction process in the production process of the collagen peptide, the temperature of the alkali liquor in the step (2) is 50 ℃;

the mass ratio of the sodium bicarbonate to the fish skin in the step (2) is 5: 1.

in the protein extraction process in the production process of the collagen peptide, the compound enzyme solution in the step (3) comprises neutral protease, papain and water;

the mass ratio of the neutral protease to the papain to the water is 1: 1: 100.

in the protein extraction process in the production process of the collagen peptide, the temperature of the compound enzyme liquid in the step (3) is 37 ℃.

In the protein extraction process in the production process of the collagen peptide, the centrifugal force of the centrifugal machine in the step (4) is 12000 g.

In the protein extraction process in the production process of the collagen peptide, the temperature of the centrifuge in the step (4) is 4 ℃.

In the protein extraction process in the production process of the collagen peptide, the aperture of the ultrafiltration membrane in the step (5) is 1000 daltons.

Comparative example 3

The protein extraction process in the production process of the collagen peptide comprises the following steps:

(1) pretreatment of fish skin: purchasing fresh fish, taking fish skin, and cleaning until the scales on the surface of the fish skin are removed;

(2) alkali liquor treatment: transferring the fish skin pretreated in the step (1) into a reaction kettle, adding alkali liquor, adding a sodium bicarbonate solution for treatment, and finally cleaning with deionized water;

(3) and (3) enzymolysis treatment: transferring the fish skin treated by the alkali liquor in the step (2) into a feed liquor tank, adding a compound enzyme solution, and draining after treatment;

(4) and (3) centrifugal treatment: transferring the fish skin subjected to enzymolysis treatment in the step (3) into a centrifugal machine, and taking supernatant after centrifugation;

(5) and (3) ultrafiltration treatment: transferring the supernatant subjected to the centrifugal treatment in the step (4) to an ultrafiltration membrane for filtration, and finally performing vacuum freeze drying.

In the protein extraction process in the production process of the collagen peptide, the variety of the fresh fish in the step (1) is silver carp.

In the protein extraction process in the production process of the collagen peptide, the mass ratio of the alkali liquor to the fish skin in the step (2) is 25: 1.

in the protein extraction process in the production process of the collagen peptide, the temperature of the alkali liquor in the step (2) is 50 ℃;

the mass ratio of the sodium bicarbonate to the fish skin in the step (2) is 10: 1.

in the protein extraction process in the production process of the collagen peptide, the compound enzyme solution in the step (3) comprises neutral protease, papain and water;

the mass ratio of the neutral protease to the papain to the water is 1: 5: 100.

in the protein extraction process in the production process of the collagen peptide, the temperature of the compound enzyme liquid in the step (3) is 37 ℃.

In the protein extraction process in the production process of the collagen peptide, the centrifugal force of the centrifugal machine in the step (4) is 12000 g.

In the protein extraction process in the production process of the collagen peptide, the temperature of the centrifuge in the step (4) is 4 ℃.

In the protein extraction process in the production process of the collagen peptide, the aperture of the ultrafiltration membrane in the step (5) is 1000 daltons.

Comparative example 4

The protein extraction process in the production process of the collagen peptide comprises the following steps:

(1) pretreatment of fish skin: purchasing fresh fish, taking fish skin, and cleaning until the scales on the surface of the fish skin are removed;

(2) alkali liquor treatment: transferring the fish skin pretreated in the step (1) into a reaction kettle, adding alkali liquor, adding a sodium bicarbonate solution for treatment, and finally cleaning with deionized water;

(3) and (3) enzymolysis treatment: transferring the fish skin treated by the alkali liquor in the step (2) into a feed liquor tank, adding a compound enzyme solution, and draining after treatment;

(4) and (3) centrifugal treatment: transferring the fish skin subjected to enzymolysis treatment in the step (3) into a centrifugal machine, and taking supernatant after centrifugation;

(5) and (3) ultrafiltration treatment: transferring the supernatant subjected to the centrifugal treatment in the step (4) to an ultrafiltration membrane for filtration, and finally performing vacuum freeze drying.

In the protein extraction process in the production process of the collagen peptide, the variety of the fresh fish in the step (1) is silver carp.

In the protein extraction process in the production process of the collagen peptide, the mass ratio of the alkali liquor to the fish skin in the step (2) is 10: 1.

in the protein extraction process in the production process of the collagen peptide, the temperature of the alkali liquor in the step (2) is 60 ℃;

in the step (2), the mass ratio of the sodium bicarbonate to the fish skin is 2: 1.

in the protein extraction process in the production process of the collagen peptide, the compound enzyme solution in the step (3) comprises neutral protease, papain and water;

the mass ratio of the neutral protease to the papain to the water is 1: 5: 100.

in the protein extraction process in the production process of the collagen peptide, the temperature of the compound enzyme liquid in the step (3) is 37 ℃.

In the protein extraction process in the production process of the collagen peptide, the centrifugal force of the centrifugal machine in the step (4) is 12000 g.

In the protein extraction process in the production process of the collagen peptide, the temperature of the centrifuge in the step (4) is 4 ℃.

In the protein extraction process in the production process of the collagen peptide, the aperture of the ultrafiltration membrane in the step (5) is 1000 daltons.

Comparative example 5

The protein extraction process in the production process of the collagen peptide comprises the following steps:

(1) pretreatment of fish skin: purchasing fresh fish, taking fish skin, and cleaning until the scales on the surface of the fish skin are removed;

(2) alkali liquor treatment: transferring the fish skin pretreated in the step (1) into a reaction kettle, adding alkali liquor, adding a sodium bicarbonate solution for treatment, and finally cleaning with deionized water;

(3) and (3) enzymolysis treatment: transferring the fish skin treated by the alkali liquor in the step (2) into a feed liquor tank, adding a compound enzyme solution, and draining after treatment;

(4) and (3) centrifugal treatment: transferring the fish skin subjected to enzymolysis treatment in the step (3) into a centrifugal machine, and taking supernatant after centrifugation;

(5) and (3) ultrafiltration treatment: transferring the supernatant subjected to the centrifugal treatment in the step (4) to an ultrafiltration membrane for filtration, and finally performing vacuum freeze drying.

In the protein extraction process in the production process of the collagen peptide, the variety of the fresh fish in the step (1) is silver carp.

In the protein extraction process in the production process of the collagen peptide, the mass ratio of the alkali liquor to the fish skin in the step (2) is 20: 1.

in the protein extraction process in the production process of the collagen peptide, the temperature of the alkali liquor in the step (2) is 50 ℃;

the mass ratio of the sodium bicarbonate to the fish skin in the step (2) is 5: 1.

in the protein extraction process in the production process of the collagen peptide, the compound enzyme solution in the step (3) comprises neutral protease and water;

the mass ratio of the neutral protease to the water is 1: 100.

in the protein extraction process in the production process of the collagen peptide, the temperature of the compound enzyme liquid in the step (3) is 37 ℃.

In the protein extraction process in the production process of the collagen peptide, the centrifugal force of the centrifugal machine in the step (4) is 12000 g.

In the protein extraction process in the production process of the collagen peptide, the temperature of the centrifuge in the step (4) is 4 ℃.

In the protein extraction process in the production process of the collagen peptide, the aperture of the ultrafiltration membrane in the step (5) is 1000 daltons.

Comparative example 6

The protein extraction process in the production process of the collagen peptide comprises the following steps:

(1) pretreatment of fish skin: purchasing fresh fish, taking fish skin, and cleaning until the scales on the surface of the fish skin are removed;

(2) alkali liquor treatment: transferring the fish skin pretreated in the step (1) into a reaction kettle, adding alkali liquor, adding a sodium bicarbonate solution for treatment, and finally cleaning with deionized water;

(3) and (3) enzymolysis treatment: transferring the fish skin treated by the alkali liquor in the step (2) into a feed liquor tank, adding a compound enzyme solution, and draining after treatment;

(4) and (3) centrifugal treatment: transferring the fish skin subjected to enzymolysis treatment in the step (3) into a centrifugal machine, and taking supernatant after centrifugation;

(5) and (3) ultrafiltration treatment: transferring the supernatant subjected to the centrifugal treatment in the step (4) to an ultrafiltration membrane for filtration, and finally performing vacuum freeze drying.

In the protein extraction process in the production process of the collagen peptide, the variety of the fresh fish in the step (1) is silver carp.

In the protein extraction process in the production process of the collagen peptide, the mass ratio of the alkali liquor to the fish skin in the step (2) is 20: 1.

in the protein extraction process in the production process of the collagen peptide, the temperature of the alkali liquor in the step (2) is 50 ℃;

the mass ratio of the sodium bicarbonate to the fish skin in the step (2) is 5: 1.

in the protein extraction process in the production process of the collagen peptide, the compound enzyme solution in the step (3) comprises papain and water;

the mass ratio of the papain to the water is 1: 5: 100.

in the protein extraction process in the production process of the collagen peptide, the temperature of the compound enzyme liquid in the step (3) is 37 ℃.

In the protein extraction process in the production process of the collagen peptide, the centrifugal force of the centrifugal machine in the step (4) is 12000 g.

In the protein extraction process in the production process of the collagen peptide, the temperature of the centrifuge in the step (4) is 4 ℃.

In the protein extraction process in the production process of the collagen peptide, the aperture of the ultrafiltration membrane in the step (5) is 1000 daltons.

Comparative example 7

Chinese invention patent, application number: cn201810396564.x, publication No.: CN108314726B discloses a giant salamander skin collagen extraction method and a collagen product extracted by the method, and the specific scheme is as follows:

the extraction method comprises the following steps: (1) obtaining giant salamander skin by the following method: removing residual meat from giant salamander skin, cutting into 0.5cm by 0.5cm, and placing in a refrigerator at 4 deg.C;

(2) fat removal: after removing meat residue, putting the cut giant salamander skin into 10 volume percent isopropanol aqueous solution (the material-liquid ratio is 1: 10), soaking for 24 hours, changing the solution once every 6 hours, rinsing for 5 times by tap water after soaking, and rinsing for 5 times by distilled water to obtain fat-free giant salamander skin;

(3) removing pigments: soaking the giant salamander skin with the fat removed in a 0.1M NaOH aqueous solution at a material-liquid ratio of 1:20 for 24 hours, changing the solution once every 6 hours, rinsing the giant salamander skin with tap water for 5 times after soaking, and rinsing the giant salamander skin with distilled water for 5 times to obtain pigment-free giant salamander skin;

(4) extraction: putting the giant salamander skin without the pigment into a citric acid aqueous solution (namely a first acid solution) with the concentration of 0.1M, taking out after 6 hours, carrying out coarse filtration by using gauze, centrifuging the filtrate for 20 minutes at 5000r/min, and obtaining a coarse extract after the centrifugation is finished;

(5) primary precipitation: adding 5M NaCl aqueous solution (first salt solution) into the supernatant to make the concentration of NaCl about 0.9M, standing for 24 hours for layering, and centrifuging at 6000r/min for 20 minutes to obtain primary precipitated collagen;

(6) secondary precipitation: adding 0.5M acetic acid aqueous solution (second acid solution) into the primary precipitated collagen to dissolve the primary precipitated collagen, taking supernate, adding 5M NaCl aqueous solution (second salt solution) to make the concentration of NaCl about 0.9M, and obtaining secondary precipitated collagen;

(7) dialyzing (MW = 500) for 3 days in distilled water, changing the solution every 12 hours;

(8) vacuum freeze drying;

(9) collecting the dry powder and weighing the weight (W) of the obtained dry powder; the experiment was repeated three times, and the data are the average of three independent experiments ".

Comparative example 8

Chinese invention patent, application number: CN201210187819.4, publication No.: CN102703555B discloses an extraction and preparation method of small molecule fish skin collagen peptide, which comprises the following specific scheme:

adding 50L of 0.01M NaOH solution containing 20% (v/v) absolute ethyl alcohol into 10 kg of tilapia skin, soaking for 12h at 20 ℃, adding 50L of 0.05M HCl solution, soaking for 1h at 20 ℃, rinsing with tap water until the pH value is 3, grinding the treated fish skin by using a separation type high-concentration refiner, heating for 60min at 90 ℃, adjusting the pH value to 8.0 by using sodium hydroxide, adding 2 g of collagenase, performing enzymolysis for 4h at 55 ℃, adjusting the pH value of enzymolysis liquid to 5.0 by using hydrochloric acid, adding 20 g of papain, performing enzymolysis for 1h at 55 ℃, separating by using an ultrafiltration membrane with the molecular weight cutoff of 5000 daltons, recovering the solution which cannot pass through the ultrafiltration membrane to a papain enzymolysis step for continuous use, heating the filtrate which passes through the ultrafiltration membrane for 5min at 100 ℃, then, desalting and concentrating by using a sodium filter membrane with the molecular weight cutoff of 200 daltons to obtain 7L of collagen peptide solution with the Brix of 25%, adjusting the pH to 4.5, adding 35g of activated carbon, decoloring, deodorizing and performing enzymolysis at 40 ℃ for 15min, removing the activated carbon by using a disk centrifuge, decoloring and deodorizing the activated carbon by using macroporous adsorption resin at normal temperature for 15min, and finally performing spray drying by using a spray dryer to obtain about 1.5kg of small-molecule fish skin collagen peptide powder with the water content of 7% (w/w).

Comparative example 9

Chinese invention patent, application number: CN201510603688.7, publication No.: CN105039483A discloses a preparation method of fish skin and fish scale collagen peptide, which comprises the following specific scheme:

in an embodiment of the present invention, a method for preparing collagen peptide from fish skin and fish scale comprises the following steps:

the method comprises the following steps: treatment of fish skin

The method comprises the steps of taking fish skin as a raw material, soaking the fish skin for 5.5 hours at a soaking temperature of 30 ℃ by using NaOH solution which is 7.5 times of the weight of the raw material and contains 0.05mol/L, removing foreign proteins and fat, rinsing the fish skin to be neutral by using clear water, soaking the fish skin for 3 hours at a soaking temperature of 30 ℃ by using HCl solution which is 13 times of the weight of the raw material and contains 0.35mol/L, rinsing the fish skin by using clear water until the pH value is 5, and grinding the fish skin to prepare the collagen solution of the fish skin.

Step two: fish scale treatment

1) Pretreatment: putting the fish scales into a water tank, adding water with the weight 16.5 times of the weight of the fish scales, and soaking for 3.5 hours to enable the fish scales to be rehydrated.

2) Decalcification: and (3) conveying the rehydrated fish scales into an acid-resistant water tank, and adding 1.5% hydrochloric acid which is 14.5 times of the weight of the fish scales to soak the fish scales for 4 hours, so that calcium in the fish scales is converted into calcium chloride to be dissolved out.

3) Neutralizing and removing impurities: adding 0.4% sodium hydroxide solution into the solution soaked with fish scales after decalcification to neutralize to neutrality, so that calcium chloride forms calcium hydroxide precipitate.

4) Washing with water: cleaning the fish scales neutralized and impurity-removed in the step 3) with clear water, and putting the cleaned fish scales into a mesh turnover basket for sprinkling water.

5) Sol: putting the fish scales cleaned in the step 4) into a reaction kettle, adding desalted water which is 13.5 times of the weight of the fish scales, and heating and cooking for 0.9 hour to obtain the water-soluble collagen solution.

6) Solid-liquid separation and filtration: firstly, cooling the prepared water-soluble collagen solution to 42 ℃, and then filtering the water-soluble collagen solution by using a filter screen to remove fish scales in the water-soluble collagen solution; and storing the water-soluble collagen solution without the fish scales in a storage tank for later use.

Step three: preparation of collagen peptide

1) Hydrolysis and enzymolysis: adding the collagen solution of the fish skin and the filtered water-soluble collagen solution into a reaction kettle, heating for 55min under 75 ℃ hot water, cooling to 50 ℃, adding a compound enzyme consisting of papain and collagenase with the weight of 0.5 percent of the weight of the raw materials, and carrying out enzymolysis for 4.5h at 50 ℃; then adding bromelain accounting for 0.2 percent of the weight of the raw materials, and carrying out enzymolysis for 2.5 hours at the temperature of 40 ℃; preparing into enzymolysis collagen peptide solution.

2) Filtering and separating collagen: filtering the prepared enzymolysis collagen peptide solution by using an ultrafilter; separating macromolecular collagen with molecular weight of more than 5000 daltons from hydrolyzed collagen solution; the protease and the incompletely hydrolyzed macromolecular collagen are trapped and added into the step 1) for continuous use.

3) Enzyme deactivation, decoloration and deodorization: heating the filtrate obtained by ultrafiltration at 90 deg.C for 15min to inactivate enzyme, adding 1.0 wt% of activated carbon for decolorizing and deodorizing, and removing activated carbon with centrifuge.

4) And (3) drying: the fish skin and scale collagen peptide with light yellow or white powder, good redissolution property and slight fishy smell is obtained after spray drying or freeze drying.

Comparative example 10

Chinese invention patent, application number: CN201811117450.3, publication No.: CN109207541B discloses a process for extracting puffer fish skin collagen peptide and application thereof, the specific scheme is as follows:

the invention discloses a process for extracting puffer fish skin collagen peptide and application thereof, wherein the extraction process comprises the following steps.

S1, raw material treatment: cutting the skin of puffer fish, scraping the fish adhered to the skin, cleaning, cutting, and freeze drying.

S2, soaking: and (4) soaking the fish skin treated in the step (S1) in a sodium chloride or sodium carbonate solution with the mass concentration of 5-10%, continuously stirring for 6 hours, filtering, washing with distilled water, and repeating for 3 times. By this step, non-collagen in the skin of the fish can be removed.

S3, enzymolysis: adding distilled water into the fish skin obtained in the step S2, and extracting collagen peptide by hydrolysis with alkaline protease, wherein the enzymolysis temperature is 45-65 ℃, the enzymolysis time is 4-5 h, the enzyme adding amount is 6000-10000U/g, and the material-liquid ratio is 1: (10-30), and controlling the pH to be 8-11 by adding a regulating solution. The pH adjusting solution is 0.01mol/L HCL or 0.01mol/L NaOH solution.

S4, enzyme deactivation: after the enzymolysis is finished, heating in boiling water bath for 10min to inactivate enzyme.

S5, centrifuging: centrifuging for 10min at 8000rpm to obtain supernatant as crude collagen peptide solution.

S6, ultrafiltration: and (3) coating the supernatant obtained by centrifugation for ultrafiltration separation, and separating by using an ultrafiltration membrane with the molecular weight of less than or equal to 10kDa to obtain the collagen peptide liquid.

And S7, freeze-drying the collagen peptide liquid obtained in the step S6 to obtain collagen peptide powder'.

Example 2

The product prepared in example 1 and the products prepared in comparative examples 1 to 10 were selected and subjected to the following tests:

the referenced patents are as follows: the invention discloses a Chinese patent with an authorization publication number of CN109207541B, which is named as a process for extracting puffer fish skin collagen peptide and application thereof.

Wherein the yield of the collagen peptide powder prepared in example 1 is 13.5%;

wherein the yield of the collagen peptide powder prepared in comparative example 1 was 12.7%;

wherein the yield of the collagen peptide powder prepared in comparative example 2 was 11.6%;

wherein the yield of the collagen peptide powder prepared in comparative example 3 was 10.4%;

wherein the yield of the collagen peptide powder prepared in comparative example 4 is 8.2%;

wherein the yield of the collagen peptide powder prepared in comparative example 5 is 7.6%;

wherein the yield of the collagen peptide powder prepared in comparative example 6 was 7.3%;

wherein the yield of the collagen peptide powder prepared in comparative example 7 was 4.8%;

wherein the yield of the collagen peptide powder prepared in comparative example 8 was 3.9%;

wherein the yield of the collagen peptide powder prepared in comparative example 9 was 10.2%;

wherein the yield of the collagen peptide powder prepared in comparative example 10 was 9.6%.

While the invention has been described in further detail in connection with specific embodiments thereof, it will be understood that the invention is not limited thereto, and that various other modifications and substitutions may be made by those skilled in the art without departing from the spirit of the invention, which should be considered to be within the scope of the invention as defined by the appended claims.