Research On Preparation Of Biologically Active Peptides By Enzymolysis From Shrimp Shell

Crawfish processing waste refers to the freshwater crawfish processing in the process of scraps from the shrimp shell shrimp head, contains many nutrients such as protein, chitin. These accounts for about 85% heavier head shrimp, shrimp shell mostly abandoned, caused a great resource waste and environmental pollution. Therefore, to extract protein lobster processed waste comprehensive utilization development research, has always been a research focus of scholars both at home and abroad. In addition to the shell of shrimp protein, organs such as heart, liver and brain tissue protein and a small amount of shrimp meat protein, these proteins have high biological activity, such as antibacterial, antioxidant, lower blood pressure and other biological activity. Based on the small lobster shrimp head of protein content in the enzymolysis liquid as an index, investigate the best pretreatment method of crayfish shrimp shell, enzymatic hydrolysis, enzymolysis liquid membrane separation technology and column chromatography after purification by vacuum freeze drying technology, shrimp shell peptide products, and further detect shrimp shell peptide related physical and chemical properties of the product and some physiological activity.In this article, through contrast experiment to determine the optimum pretreatment process: 100 ℃ heat 2 min 1% NaCl solution and 5% acetic acid treatment 4 h, cleaning and medical alcohol 18 h, wash to press press, mixed enzyme digestion. Shrimp shell protein extraction and the optimal process condition is: the alkaline protease enzymolysis 3 h(pH7.5, temperature 40 ℃, enzyme amount 0.3%) and pepsin enzyme solution 1 h(pH3.0, temperature 40 ℃, enzyme amount 0.2%), can obtain the highest protein extraction rate of digestion, protein extraction rate was 86.1%, the protein content in the enzymolysis liquid is 6.715 mg/mL. Determine the enzymolysis liquid’s original crayfish shrimp shell for separation and purification of the optimal purification scheme: shrimp shell enzymolysis liquid through 200 mesh filters, the filtrate obtained under pressure filtration system with 300 molecular weight nanofiltration membrane intercept enrichment, concentrate using AKTA Prime Plus column chromatography system, 30 pg superdex glucan gel column for protein chromatography purification. Collect 15 min- 23 min, 42 min- 45 min, 45 min- 60 min 3 period of eluent, rotary evaporation drying shrimp shell peptide products after enrichment. Prawn shell peptide powder composition analyzed, measured protein content is 70.02%, moisture content is 70.02%, the ash content is 4.1%, the Ca content is 3600 mg/kg, Cu content is 0.39 mg/kg, Pb content is 0.51 mg/kg, zinc content is 1.4 mg/kg, Fe and Cr element detection, soluble total sugar content of 17%. Its original crayfish shrimp shell peptide has good antioxidant activity, measured by high performance liquid method of shrimp shell peptide has obvious higher than that of ck hippuric acid absorption peak, which has significant ACE inhibitory effect. ’s original crayfish shell peptide of staphylococcus aureus have good antibacterial effect, bacteriostatic effect as gram the improvement of the original crayfish shell peptide concentration increased. Was also found that high levels of the original crayfish shell peptide is good inhibitory effect on escherichia coli, but’s original crayfish shell peptide no inhibition to bacillus subtilis and aspergillus Niger. Using LC- MS subsection and determine the molecular weight of shrimp shell peptide molecular weight distribution, identification of the shrimp shell peptide main ingredients for small molecule hybrid peptide molecular weight below 1000.