Study On Ferrous Chelate Modification And Bioactivity Of Collagen Peptide From

In this research, the skin of tilapia was used for the study. The hot water method was used for the extraction of gelatin from the skin of tilapia and then the tilapia skin gelatin (TSG) was hydrolyzed by neutral protease for preparation of active peptides. Finally, the antioxidant and antibacterial properties of iron-TSGP chelate were determined. The research results are as follows:(1) Determination of the basic composition of tilapia skin, the content of the crude protein was26.71%, which accounted for90.00%of the dry matter. Acid and alkali solution were used for pretreatment of the tilapia skin, then the collagen was extracted from tilapia skin using45℃hot water for12h, and the yield was18.19%. Trypsin, neutral protease and alcalase were selected to hydrolyze TSG, according to the iron-chelating activity of hydrolysate. The optimal conditions of neutral proteinase was determined by the orthogonal test as pH7, temperature45℃, E/S5%, time3h. Under these hydrolysis conditions, the degree of hydrolysis was12.35%, and the rate of iron-chelating reached97.86%.(2) The influence factors of iron-chelating reaction were investigated, including mass ratio of TSGP with ferrous salt (mTSGp:mFeCl2.4H2O), the initial pH, time and temperature. In this research, The optimum parameters of preparing iron-TSGP chelate are as follows: mTSGP:mFeCl2.4H2O=500:1, pH5.5, time50min, temperature35℃. Under these conditions the rate of iron-chelating reached99.00%. The structure of iron-TSGP chelate was determined by the Ultraviolet and Infrared spectroscopy, and observed that the carboxyl and amino group of TSGP bound with iron.(3)Study on the antioxidant and antibacterial activity of the chelate showed that the scavenging ability of the chelate on DPPH·, ABTS·+, hydroxyl radical were all enhanced with increasing concentrations, and their IC50values were0.84、0.52and0.52mg/mL respectively. Besides, ferric reducing antioxidant power had a positive correlation to the concentration of chelate. Antibacterial experiments indicated that chelate had a certain antibacterial activity to both of gram-negative and gram-positive bacteria, such as:E. coli Salmonella, Staphylo coccus aureus and Sacillus subtilis. It was round out that the chelate may be a broad spectrum antimicrobial agent to bacterial.