Extraction Of Cow Leather Collagen Peptide By Enzymatic Hydrolysis And Preparation Of Its Oral Liquid

Collagen is an important functional protein, which is closely related to cell proliferation, differentiation, movement, immune,joint lubrication, wound healing and affects our body growth, aging and health directly or indirectly. It is widely used in medicine,food, daily chemical, biosynthesis and other industrial fields because of its weak antigenicity, good biocompatibility, such asmedical capsule, surgical operation material, edible gelatin, gelatin and cosmetics etc.Although the collagen extracted from animal tissues has rich nutrition, its unique three spiral structure is very stable innature. It can’t be destroyed completely by processing technology, which leads to its difficult digestion and absorption.Hydrolyzing collagen into small peptide by enzymatic hydrolysis can significantly improve its digestion and absorption. It isincreasing interests in the production of small peptide by collagen hydrolysis.Fresh leather was used as raw material to prepare small collagen polypeptide using complex enzyme to hydrolysis step bystep in this study. The preparation process was optimized by response surface experiment, and the mixed peptides wereseparated, purified and molecular weight determined by Sephadex column chromatography and SDS-PAGE. Oral liquid wasprepared as a functional healthy product with the collagen polypeptide.Main results were as follows:1、The addition order and proportion of the complex enzymes were confirmed, selecting papain and trypsin as the complexenzymes. The preparation process was optimized by single factor experiment and response surface test, the optimized hydrolysisconditions were gotten combining with the actual situation obtained as follows. Adding the complex enzymes at a proportion of3:1, at50℃for7hours, with the total addition of650U/mL. The extraction yield of leather collagen peptide can reach to32.02%under this condition.2、Active carbon was used for decolorization of collagen polypeptide mixture, the optimized condition of decolorizationobtained by comparing the decolorization rate and peptide loss rate was as follows, add2%active carbon at30℃for20minutes.The decolorization rate reached65.04%and the peptide loss rate was30.37%under this condition.3、Sephadex Column chromatography and twelve sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE)were used to separate, purify the collagen polypeptide and determinate the molecular weight and distribution. The resultindicated that the molecular range of the mixed polypeptide was3~10KDa and3solution peaks were gotten by G-50columnchromatography, whose molecular weight were3.0KDa,6.0KDa and10.0KDa.4、Peptide mixture was used as raw material to make oral liquid with the sensory evaluation as the main index. The oral liquidproduction process was obtained, yeast powder addition was0.02%(m/v), ferment at25℃for2h. Add the honey, citric acid,glycine and sugar at the amount of2%,0.6%,0.6%and8%in turn respectively and stabilize the oral liquid with xanthan gum,CMC-Na and EDTA-2Na at the amounts of0.06%,0.06%and0.30%. The indicators are composite national standards bydetecting the quality indicators.