Studies On Extraction Of Collagen Peptide From Sheep Cartilage And Antibacterial Activity Of Collagen Pptide

The sheep cartilages as raw materials,in this experiment. Extracted collagen by pepsin and acetic acid, then obtained collagen peptides with antibacterial activity by alkaline hydrolysis. Collagen peptide the best extraction conditions by the orthogonal experiment determined. Study on the antimicrobial stability of collagen peptides, the results were as follows:Sheep cartilage extracted collagen, collagen identified as type Ⅱ collagen by ultraviolet absorption spectra and SDS polyacrylamide gel electrophoresis.Collagen peptides with antibacterial activity extraction stage:Using of pepsin, papain, neutral protease, trypsin and alkaline hydrolysis sheep cartilage collagen, antibacterial rate as index, only alkaline protease capable of hydrolyzing the collagen peptide having antibacterial activity, alkaline protease is selected as the optimal proteinase. Single factor test and orthogonal test by enzyme dosage (enzyme and substrate concentration ratio), time, pH and temperature on the inhibition rate and the degree of hydrolysis of collagen peptide extraction process optimization, results shows that alkaline protease to substrate Ieve of 4%, temperature of 60℃,reaction time of 2.5h, pH of 9. On this condition,collagen peptide antibacterial activity reached 43.1%, degree of hydrolysis reached 52.8%.E. coli and B. subtilis as indicator bacteria, the effects of temperature, pH, organic solvents, surfactants, sodium nitrite, ultraviolet light, metal cations, storage temperature and time on collagen peptide antibacterial stability. The results showed that antibacterial activity of collagen peptide is stable to heat, in a wide pH range (pH3-11) have antibacterial activity, Organic solvents, sodium nitrite, ultraviolet light, storage temperature and time unaffected antibacterial antibacterial activity of collagen peptide, surfactants as Tween20、Tween80、SDS、TritonX-100 and Urea unaffected antibacterial activity of collagen peptide, But collagen peptide antibacterial activity was significantly enhanced by EDTA. Metal cations. Mg2+,Ca2+,Cu2+,Zn2+and Fe2+ will decrease in antibacterial activity of collagen peptide. Good antimicrobial stability of collagen peptides, and frozen and refrigerated are very well tolerated of Collagen peptide, great potential as antibacterial agents in food.