Studies On Immobilization Of Ginger Protease

This research takes chitosan as material and focused on the producing technology and properties of chitosan microspheres, ginger protease immobilizing technology, enzymology properties of immobilized ginger protease and influences of some agents to it. The main results of this research are listed as following:1. Making activity chitosan microspheres uses emulsion-crosslinking, the optimal conditions are: the concentration of chitosan sol is 3%, oil-water is 2:1, mixing time is 90min, the volume of glutaraldehyde is 1mL, the volume of ethyl acetate is 8mL. With this optimal conditions, the products of chitosan microsphere has good adsorption property, good swelling, forms size and alkaline endurance etal.2. With sole factor assays, the immobilized ginger protease through adsorption and crosslink methods is analyzed at the aspects of enzyme giving amount, glutaral pentanedial eventual concentration, cross-link and adsorption time. The optimal ginger protease immobilization conditions are determined through L9(34) orthogonal assays, which include: the enzyme giving quantity is 0.6mg/g, the glutaral pentanedial eventual concentration is 0.8%, the cross-link time is 2h, and the adsorption time is 16h. As a result, the activity of immobilized ginger protease is 672.6 U/g, and the recycle rate of enzyme is 69.3%.3. The enzymology properties of immobility ginger protease is studied, and results show that: the optimal pH is 5.0, with one unit offset towards acidic values compared with free enzyme; the optimal temperature is 70℃, 10℃higher than free enzymes. The stabilities of immobilized ginger protease in acidic or alkaline solutions and heat endurance are significantly improved compared with free enzyme, and these are advantages in improving its utilization ratio in industrial use.4. Organic reagents and food additives can affect the activity of both immobilized and free ginger protease: inhibitors include ethylene glycol, methanol, sodium bisulfite, and sodium chloride etc; activators include carbamide and sugar, which perform a significant effect, while guanidine hydrochloride performs a not-significant activate effect. At the same time, data show that immobilized ginger protease shows an inert change in activation and inhibition compared with free enzyme.