Study On Enzymatic Hydrolysis And Membrane Technology Of Preparing Scale Collagen Oligomeric Peptides

In this study, study on preparing higher value-added and high biological activity collagen oligopeptide by complex enzyme hydrolysis technique and membrane technology from Tilapia scale were carried out, The whole researeh was aiming at providing a scientific basis for effective utilization of fish scale.In this work, basic components of Tilapia scale, pre-treatment of scale, the selection of complex enzyme and the optimization of enzyme hydrolysis Condition, the selection and work characteristics of membrane and technology of vacuum freeze-drying were investigated.The main research results were as follows:1. The decalcifying and degreasing process of fish scale were studied. The concentration of acid and alkali, time of processing, and the solid-liquid ratio significantly influenced the effect of pre-treatment. The results show that:decalcification rate reached above 98% when 3% hydrochloric acid was used with 1:15 solid-liquid ratio for 4h; when 8% Sodium Hydroxide was used with 1:15 solid-liquid ratio for 3h,the fat content decreased to 0.16%-0.22%, the collagen content can increase to 93.6%～94.1%.2. The extraction technology of scale collagen oligopeptide was investigated. The complex enzyme and condition were determined. The results showed the optimal condition of enzyme hydrolysis was using 2% animal protease and neutral protease with a proportion of 1:1.2, ratio of solid-liquid 1:8, temperature between 58 60℃,pH=6.8～7.0,extraction time 4 hours. The conversion of collagen oligopeptide reached 94%-95%, the collagen oligopeptide of content is 86.6%～88.2%.3. The impurity removal and concentration technology of enzyme solution was researched and discussed. The enzyme solution was done by there-order-membrane technology which were 100nmMF,MWCO2500DalUF and MWCO300-500NF.the purity of collagen oligopeptide raised to96%, the collagen oligopeptide with molecular weight between 300-1000Dal content increased to above 95%, quality of oligopeptide was greatly improved.4. Vacuum freeze-drying technology of concentrated solution was studied. The analysis of the experimental results showed that the optimum technical conditions of the freeze-drying as follow:heating temperature of shell was 65℃, the material thickness was 12mm, the hothouse pressure was 50Pa, freeze-drying rate and time were 140 L×h-1×m-2 and 19.5-20h respectively.