Study On Co-hydrolysis Process Of Functional Components Of Bovine

Bovine cartilage is a by-product of cattle slaughter,rich in collagen and chondroitin sulfate,so it is widely used as a raw material for the extraction and preparation of these functional components.In this paper,using bovine cartilage as the experimental raw material,the co-hydrolysis process of its functional components,collagen and chondroitin sulfate,was studied,in order to produce collagen peptides and low molecular weight chondroitin sulfate in the same system.This paper aims to provide new ideas for the comprehensive utilization and development of bovine cartilage.Firstly,four kinds of cartilage,including nasal cartilage,laryngeal cartilage,crescent cartilage and soft costal cartilage,were selected,and their basic components,collagen and chondroitin sulfate contents were determined after removing non-cartilage components,and histological observation was carried out.Three chemical treatments（4%Na Cl,0.05 M Na OH,their combination）were used to remove impurity proteins in cartilage,and the best way to remove impurity proteins was explored.The results showed that there were differences in the contents of basic nutrients of the four cartilages,and the contents of collagen and chondroitin sulfate were significantly different.Among them,crescent cartilage was rich in collagen and chondroitin sulfate and was suitable for co-hydrolysis.The results of the removal of impurity proteins showed that 4%Na Cl treatment effectively removed impurity proteins while reduced the damage to chondroitin sulfate and the loss of cartilage during the treatment,compared with 0.05 M Na OH treatment or the combination of them.Secondly,this paper optimized the hydrolysis process of collagen.Papain,Trypsin and Alkaline protease were respectively selected to hydrolyze collagen.In order to explore the best process technology of low molecular weight collagen peptides,the addition amount and hydrolysis time of the three enzymes were optimized,based on the extraction rate,molecular weight distribution and hydrolysis degree of collagen.The results showed that when the amount of papain was 3%and the hydrolysis time was 6 h,the extraction rate of collagen in the enzymatic hydrolysis solution was 37.03%,of which 91.80%of the peptides had a molecular weight of less than 10 k Da;when the amount of trypsin was 2.5%,the hydrolysis time was 5 h,the extraction rate of collagen in the enzymatic hydrolysis solution was 39.13%,of which 84.04%of the peptides had molecular weights less than 10 k Da;when the addition amount of alkaline protease was 3.5%,and the hydrolysis time was 3 h,the collagen in the enzymatic hydrolysis solution was 3 h,the extraction rate of protein was59.23%,and 90.87%of the peptides had molecular weights less than 10 k Da.By comprehensively comparing the optimized hydrolysis effects of the three enzymes and considering the principle of economy,it is believed that alkaline protease can be better applied to the industrial production of low molecular weight collagen peptides.Subsequently,the hydrolysis process of chondroitin sulfate was optimized.Five hydrolysis methods（hydrochloric acid,VC-H₂O₂system,Fe-H₂O₂system,Hyaluronidase,Chondroitinase ABC）were estimated respectively,with the molecular weight distribution of chondroitin sulfate as an index.The results showed that the optimal process for hydrochloric acid hydrolysis of chondroitin sulfate was to use 0.5 M HCl for 1 h at room temperature;the optimal process parameters for hydrolysis of VC-H₂O₂system were to use60 m M H₂O₂and 60 m M VC to react and keep it at 35℃,180 W for 120 min;the optimal process parameters for the hydrolysis of Fe-H₂O₂system was to use 100 m M H₂O₂and 0.1m M Fe SO4 to react and keep it at 55℃,90 W for 120 min;The best process of Hyaluronidase was to use 1.75%addition amount,and put it in p H=6,37℃environment for 10 h;the best process of using Chondroitinase ABC was to use 40 U/g addition amount,and put it in p H=8 and 37℃for 0.5 h.By monitoring the changes in the primary structure of chondroitin sulfate,the extraction rate and molecular weight of collagen during the hydrolysis process,it was found that HCl treatment could retain the functional groups of chondroitin sulfate and had non-specific hydrolysis of each component in the co-hydrolysis system,which are believed to meet the intended purpose of the co-hydrolysis.Finally,the final product under the optimal co-hydrolysis process is subjected to physical and chemical detection.The results showed that the co-hydrolyzed final product was mainly composed of low molecular weight collagen peptides and chondroitin sulfate,which all meet the sensory requirements,physical and chemical indicators and pollutant limit standards in the related national standard of China.The average molecular weight of chondroitin-based polysaccharide was about 7.2 k Da,which basically conforms to the product characteristics of high bioavailability in previous studies.At the same time,the types and content of amino acids and monosaccharides in the final product were also characterized,laying a foundation for further exploration of the physiological activity of the final product.