Preparation Of Collagen Peptides With Controllable Molecular Weight Range Based On Enzymatic Degradation Coupled With Membrane Separation

Collagen peptide is a kind of small molecule polypeptide mixture,which is obtained by enzymatic method and thermal degradation method.It is widely used in functional foods,beauty skin care products,and so on.Collagen peptides have antioxidant,preventing osteoporosis and angiotensin converting enzyme(ACE)activity.So the preparation of collagen peptide is significant and has become a hot research.The traditional method have some drawbacks,such as the wide range of molecular weight,imperfect process conditions.Based on the study of the traditional enzymatic reaction process of collagen proteases,we investigated the extraction technology of collagen peptide based on ultrafiltration membrane separation technology.Molecular weight range of the prepared collagen peptide was detected by high performance gel chromatography.Molecular weight homogeneous polypeptide obtained was explored with bovine gelatin.The details are as follows:1.Enzymatic Hydrolysis: The process was carried out with different proteases.And enzymatic kinetics was explored.Enzymolysis rate and enzymolysis degree were explored.As shown in the results,the proportion of small molecular peptides was less than 10 k Da within 60 min,Alkaline protease 44.7%,Trypsin 39.8%,Papain 35.7%,Neutral Protease 15.3%.2.Separation of Collagen Peptide Membrane: The trans membrane behavior of the polypeptide was based on enzymatic-membrane separation process,the effects of solution volume and circulating flow on the Trans membrane behavior of different molecular weight peptides during the ultrafiltration treatment of gelatin were also studied.The detailed experiments were performed on 1200 m L,600 m L,300 m L gelatin solution,the change of polypeptide composition in the range of 3k Da was 7.84%,16.99% and 21.05%.3.Enzyme-Membrane separation process: The membrane separation and integration process were continuous enzymatic reaction.Peptide was filtered through hollow fiber membrane.Experiments were carried out with alkaline protease.Under optimal conditions of 3k Da hollow fiber membrane,enzymatic hydrolysis-membrane separation was achieved within 60 min.Enzyme hydrolysis rate was improved by 15% compared with traditional method.Molecular weight of the obtained polypeptide was about 1700 and 600 Da.