阅读说明：本技术 一种酸浸提取猪皮胶原蛋白的方法 (Method for extracting pigskin collagen through acid leaching ) 是由 曾巧辉 梁敬林 王敬敬 朱钧婷 何嘉颖 范玮煊 刘壮彬 于 2019-12-30 设计创作，主要内容包括：本发明属于食品加工的技术领域,公开了一种酸浸提取猪皮胶原蛋白的方法。所述方法：1)将猪皮用磷酸盐清洗,采用水冲洗,沥干,冷冻干燥,粉碎,获得猪皮粉末；2)将猪皮粉末置于氯化钠溶液中浸泡处理10～16h,离心,获得沉淀物；3)将沉淀物加入酸中进行酸解,后续处理,获得猪皮胶原蛋白；所述酸为乙酸、柠檬酸、乳酸中一种以上。本发明的方法简单,所获得的胶原蛋白提取率高,品质好。(The invention belongs to the technical field of food processing, and discloses a method for extracting pigskin collagen by acid leaching. The method comprises the following steps: 1) washing pigskin with phosphate, washing with water, draining, freeze drying, and pulverizing to obtain pigskin powder; 2) soaking the pigskin powder in a sodium chloride solution for 10-16 h, and centrifuging to obtain a precipitate; 3) adding the precipitate into acid for acidolysis, and performing subsequent treatment to obtain pigskin collagen; the acid is more than one of acetic acid, citric acid and lactic acid. The method is simple, and the obtained collagen has high extraction rate and good quality.)

1. A method for extracting pigskin collagen by acid leaching is characterized in that: the method comprises the following steps:

1) washing pigskin with phosphate, washing with water, draining, freeze drying, and pulverizing to obtain pigskin powder;

2) soaking the pigskin powder in a sodium chloride solution for 10-16 h, and centrifuging to obtain a precipitate;

3) adding the precipitate into acid for acidolysis, and performing subsequent treatment to obtain pigskin collagen; the acid is more than one of acetic acid, citric acid and lactic acid.

2. The method for acid leaching extraction of pigskin collagen according to claim 1, wherein: the pH value of acidolysis in the step 3) is 1.8-3, the acidolysis time is 12-72 hours, and the mass volume ratio of the precipitate to the acid is 1g to (10-50) mL.

3. The method for acid leaching extraction of pigskin collagen according to claim 2, wherein: the pH value of the acidolysis in the step 3) is 2.1-2.5.

4. The method for acid leaching extraction of pigskin collagen according to claim 1, wherein: the mass concentration of the sodium chloride solution in the step 2) is 10 wt%; the mass ratio of the pigskin powder to the sodium chloride solution is 1g to (40-60) mL;

the rotating speed of the centrifugation is 6000-9000 r/min, and the time of the centrifugation is 5-15 min.

5. The method for acid leaching extraction of pigskin collagen according to claim 1, wherein: the pH value of the phosphate in the step 1) is 6-8;

and 3) performing subsequent treatment, namely centrifuging after acidolysis, taking supernatant, salting out, centrifuging again to obtain crude collagen, dissolving the crude collagen in corresponding acid, dialyzing in a disodium hydrogen phosphate solution and water in sequence, and freeze-drying to obtain the pigskin collagen.

6. The method for acid leaching extraction of pigskin collagen according to claim 5, wherein: the rotating speed of the centrifugation is 6000-9000 r/min, and the time of the centrifugation is 5-15 min; the salting-out refers to adding sodium chloride until the concentration of NaCl is 2-4 mol/L, and the concentration of a disodium hydrogen phosphate solution is 0.02 mol/L; the dialysis time of the disodium hydrogen phosphate solution is 2-3 days, and the dialysis time in water is 1-2 days.

7. The method for acid leaching extraction of pigskin collagen according to claim 1, wherein: the pigskin is pretreated in the step 1), and specifically, the pigskin is cleaned, and subcutaneous fat and surface hair are removed.

8. A pigskin collagen obtained by the method of any one of claims 1 to 7.

Technical Field

The invention belongs to the technical field of food processing, and particularly relates to a method for extracting collagen from pigskin by acid leaching.

Background

With the rapid development of national economy, the consumption level of people is increasingly improved, China becomes a world with a large number of pork production and consumption, but a large number of pig by-products (such as pigskin) can be produced when pork is consumed in large quantities. The pigskin is a main by-product after pork slaughter, and the main application field is the tanning industry. However, the quality of the leather made of the pigskin is inferior, and the utilization rate of the pigskin for leather making is only 20-30%, so that the utilization rate of the pigskin as a leather making material is reduced year by year. However, pigskin is also useful as a tanning material. The pig skin contains 33% of protein, and about 87.7% of the protein is collagen. The collagen has good physical properties and biological characteristics, and has wide application in the industries of food, chemical engineering, biological materials and the like. Therefore, the collagen is extracted from the pigskin and the extraction rate is optimized, so that the method has profound significance for increasing the economic value of pigskin resources.

The pigskin is mainly divided into two parts in food industrialization, firstly, the pigskin is directly added into food after being pretreated by crushing, emulsifying, heating and the like, and is generally widely applied to recombined food. On the other hand, since pig skin is rich in collagen, and further hydrolysis of collagen can yield gelatin and collagen polypeptide, pig skin is also often further processed to make gelatin for use in food packaging materials, and hydrolyzed collagen polypeptide is added to health foods.

Collagen is a protein with a special structure, which is mainly distributed in extracellular matrix or basement membrane of connective tissues such as bones, tendons, ligaments, etc., and forms a fiber network structure in the form of collagen fibrils and collagen fibers. Collagen belongs to extracellular matrix (ECM), is an important component in the body, and is a complex composed of various proteins, which completes the tissue structure and biological functions by connecting the tissue structures. In daily life, collagen is widely applied to food, beauty treatment, pharmacy, membrane materials and the like. Collagen is a high molecular weight protein, and collagen fibers generally play a role as a scaffold in tissue structure, and play a supporting role to ensure normal functioning of tissue.

The collagen is partially hydrolyzed to obtain soluble collagen, i.e., gelatin, which is mainly derived from animal skin, bones, tendons and cartilage. The gelatin has better gel forming property and hydrophilicity, and is widely applied to the aspects of food, beauty treatment, pharmacy and the like; gelatin also has good emulsifying and film-forming properties, and is gradually replacing traditional synthetic materials, and is applied as an emulsifier, a foaming agent, a colloid stabilizer, a biodegradable film-forming material, a microcapsule preparation and the like.

The acid extraction of collagen generally refers to a process of immersing a raw material in an acidic solution such as phosphoric acid, hydrochloric acid, sulfurous acid, or the like. The acid extraction method has the advantages of rapid reaction, short treatment time and the like, but the method has low collagen yield and serious corrosion to production equipment. In addition, when extraction is performed using a strong acid such as hydrochloric acid, the time, temperature and pH of acid leaching are important factors affecting the extraction effect of collagen, and when these factors are not properly designed, collagen may be completely hydrolyzed into amino acids or a part of amino acid structures (such as tryptophan and serine) may be damaged, and the purity of the product is low due to the difference in the degree of hydrolysis of the collagen.

Further research is needed to fully utilize pigskin and efficiently extract collagen from the pigskin, and obtain pigskin collagen with high extraction rate and good quality.

Disclosure of Invention

In order to fully utilize the pigskin and overcome the defects and shortcomings of the prior art, the invention aims to provide a method for extracting pigskin collagen by acid leaching. The invention adopts acetic acid, citric acid and lactic acid to extract the collagen of the pigskin, and the obtained collagen has high extraction rate, good water solubility and good quality. The obtained pigskin collagen is used in the field of food processing.

In order to solve the technical problems, the invention is realized by the following technical scheme:

a method for extracting pigskin collagen by acid leaching comprises the following steps:

1) washing pigskin with phosphate, washing with water, draining, freeze drying, and pulverizing to obtain pigskin powder;

2) soaking the pigskin powder in a sodium chloride solution for 10-16 h, and centrifuging to obtain a precipitate;

3) adding the precipitate into acid for acidolysis, and performing subsequent treatment to obtain pigskin collagen; the acid is more than one of acetic acid, citric acid and lactic acid.

The pH value of acidolysis in the step 3) is 1.8-3, preferably 2.1-2.5, the acidolysis time is 12-72 h, and the mass-to-volume ratio of the precipitate to the acid is 1g to (10-50) mL.

The mass concentration of the sodium chloride solution in the step 2) is 10 wt%; the mass ratio of the pigskin powder to the sodium chloride solution is 1g to (40-60) mL. The rotating speed of the centrifugation is 6000-9000 r/min, and the time of the centrifugation is 5-15 min.

The pigskin is pretreated in the step 1), and specifically, the pigskin is cleaned, and subcutaneous fat and surface hair are removed.

The pH value of the phosphate in the step 1) is 6-8. Phosphate refers to phosphate buffer solution.

And 3) performing subsequent treatment, namely centrifuging after acidolysis, taking supernatant, salting out, centrifuging again to obtain crude collagen, dissolving the crude collagen in corresponding acid, dialyzing in a disodium hydrogen phosphate solution and water in sequence, and freeze-drying to obtain the pigskin collagen. The rotating speed of the centrifugation is 6000-9000 r/min, and the time of the centrifugation is 5-15 min; the salting-out refers to adding sodium chloride until the concentration of NaCl is 2-4 mol/L, and the concentration of a disodium hydrogen phosphate solution is 0.02 mol/L; the dialysis time of the disodium hydrogen phosphate solution is 2-3 days, and the dialysis time in water is 1-2 days.

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

the invention uses citric acid and lactic acid to extract the collagen of the pigskin, and the obtained collagen has high extraction rate and high quality. The obtained pigskin collagen is used in the field of food processing.

Detailed Description

The present invention will be described in further detail with reference to examples, but the embodiments of the present invention are not limited thereto.