Study On Manufacture Of Active Peptide From Silkworm Chrysalis Protein By Enzymatic Hydrolysis

Such life nutrient compositions as rich protein, fat, phospholipids, inorganic salt, and vitamin exist in silkworm chrysalis, the dormancy stage of silkworm growth and the parent of breeding. Especially, the protein content is high. Silkworm chrysalis is a good insect animal protein source with high nutrition and medicinal value. The protein enzymolysis is the process of generating such the low molecular weight products as peptide and peptone through hydrolysis under catalysis. Active peptide is a sequence of debris with special bioactivity in the structure of protein and can be gotten by the proteolysis of animals and plants. Silkworm chrysalis is the research object of the thesis. On the basis of analyzing the system of silkworm, the thesis researches the rule of hydrolysis of silk worm chrysalis protein, which includes:We investigated the content of water, protein, pupa oil of silkworm Chrysalis in different filature factories by experimental method. We knew the better condition of petroleum ether to extract pupa oil by orthogonal experimental method:temperature60℃, time2h, material liquid1:10. It is gotten that silkworm chrysalis protein is made up of18Amino acids by HPLC method.8necessary Amino acids of human being account for60%of the total. The content and ratio of amino acid are in line with the provisions of the FAO/WHO ideal protein mode. The hydrolysis degree is used for investigation and the appropriate pupa enzyme solution protease for alkali protease is screened. It was investigated that the major content of Skim silkworm powder by international standard method is:protein68.86%, fat8.7%, water4.63%, and ash3.12%. The optimum process condition of enzymatic hydrolysis of silkworm chrysalis protein is gotten by single factor experiments:substrate concentration6%～8%, enzyme dosage0.05%, pH9.50,temperature50℃and hydrolysis time6.0h. At this time, degree of hydrolysis of silkworm chrysalis is24.67%and enzymatic hydrolysate of silkworm chrysalis is small peptides.According to the experimental data and empirical formula, dynamic model of hydrolysis degree at50℃when alkali protease hydrolyze silkworm protein is:DH=4.5511n[1-(1.4663Eo/So+0.0164)t]; the equation of hydrolysis rate dynamic:r=(6.9725E0+0.0781S0)exp[-0.2103(DH)]; the mechanical model of enzyme activities,:ab=1.4782Eo/S0+0.0156。 Dynamics constant is k2=6.9725min-1; and enzyme inactivation constant is kd=1.4782min-1。 It is proved that dynamic model and experimental results are identical with each other and the model is with practical value.