Study On The Bioactivities And The Safety Of Peptide From Oil-tea(Camellia Oleifera Abel) Seed Meal Protein

The polypeptide in Camellia oleifera Abel was prepared by hydrolyzing the protein of Camellia oleifera Abel. The antioxidant activity, bacteriostatic activity and the safety of the polypeptide were studied. The results were as follows:Five proteases (Alcalase, Papain, Trypsin, Flavorzyme, Neutrase) were examined on the antioxidative capacity of their hydrolysates on linoleic acid, furthermore, the software of Design-Expert7.1Trial was used to determine the best processing parameters for the enzymatic hydrolysis. The results indicated that Alcalase was the best of the five proteases and the optimal enzymolysis conditions were: pH8.0, substrate concentration16.8mg/g, temperature48.8℃and enzyme treating time6.5h. The inhibition of linoleic acid peroxidation of the polypeptide obtained under above conditions was60.83%±0.57%(n=3), and the result was closed to prediction61.86%, this indicates that the parameters by Response Surface Method are reliable.The antioxidant activity in vitro of polypeptide in camellia meal was further studied by testing the reducing power, ability of hydroxyl radicals (OH·) scavenge, chelating ability with Fe2+and ability of DPPH radicals scavenge. The result showed that the polypeptide in camellia meal had a better effect on scavenging the hydroxyl radicals (OH·) and DPPH radicals, the IC50was0.181g/L and0.367g/L respectively and was1.56and52.4times of the vitamin C. The chelating ability with Fe2+was3890times of EDTA. The moderating effect of polypepide in camellia meal on antioxidant of mouse was studied by the animal model. The mouse got the hepatotoxicity after fed with carbon tetrachloride, then different count of polypepide was fed in to the mouse after1h.24h later the activity of SOD and GSH-Px, the content of malonaldehyde in the liver of mouse was determined. The result showed that the polypeptide in camellia meal can decrease the mount of malonaldehyde and increase the activity of SOD and GSH-Px. It indicated that the polypeptide in camellia meal has an obvious function of antioxidant.We hydrolysis using Pepsin protease and optimization the enzymatic hydrolysis technology by Taking oil-tea meal protein as raw material. In order to antimicrobial index,4factors with5levers were designed in the experiment. The result showed that the optimum conditions were:enzyme amount0.22%, pH2.36, temperature36.82℃, time5.99h. By this condition, the inhibition rate is67.08%±0.22%(n=3)which was near to the prediction value of67.32%.We made acute toxicology experiment, sperm malformation test and30days feeding trials experiment according to the Food safety assessment procedures and methods of toxicology. We made acute toxicity test with oil-tea meal polypeptide on large mice and small mice by a maximum limit method (intake is20.00g/kg, kW),no death; we made mice sperm abnormality test, Ames test and bone marrow polychromatic erythrocyte micronucleus test, all the result are negative; all the indicators are no exception in30days feeding trials experiment, showed that oil-tea meal polypeptide belongs to nontoxic.