Preparation Of Sheep Bone Collagen Polypeptide Enzymatically And Preparion Of Calium Chelated Polypeptide

Oesteoporosis is a growing health concern with an enormous impact on the morbidity of many diseases, and especially in China. The existing therapeuitic drugs are effective but hazardous. Hence it is urgent to develop a more safe,effective, side-effect free and long-term taken product to prevent the occurance of the osteoporosis. Previous studies proved that calcium chelated polypeotide is such a kind of oesteoporosis preventive drugs and calcium supplement. China is a big live stock feeding country and has abundant bone resources, but lack of deep exploitation of bone resources. The present study aims to prepare sheep bone collagen polypeptide by enzymatic hydrolysis and calcium chelated polypeptide.Single-factor tests were used to determine the hydrolysis condition of alcalase, flavourzyme, neutrase, pepsin, trypsin,compound protease and papain. In light of degree of hydrolysis,alcalase(A), compound protease(B) and flavourzyme(C) had the highest capacity to hydrolyze the sheep bone powder in sequence compared to other 4 kinds of protease.During the hydrolyzing process of 7 kinds of single enzyme,4 indices including degree of hydrolysis, amount of formed polypeptide, yield of short peptide and amino-nitrogen were used to evaluate the efficiency of hydrolyzing. Results showed all these indices were in extremely significant positive correlation with each other.The hydrolyzing conditions for 3 enzymes A,B and C were optimized by Box-Behnken center-united design and the method of response surface analysis together with SAS.Results showed the parameters for alcalase(A) were 9% substrate(W/V),4.25% enzyme(E/S),45 ℃,325min,pH 9,28.12% DH was obtained. 28.54% of DH can be obtained for compound protease(B) under the condition of 9%(W/V)substrate,5% (E/S) enzyme, incubation at 55 ℃ for 300min under pH7.5. The optimized parameters for flavourzyme were 12%(W/V)substrate、3.56%(E/S) 55℃,315min and pH6 with a DH of 20.38%. Results suggested that DHs of 3 enzymes under the optimized condition were significantly higher than those before optimization.To further elevate the DH value, combinations of A+B, A+C and B+C were tested to determine the best hydrolyzing fashion for the highest DH value for each combination. Results demonstrated that the highest DH for A+B was 29.79% which was obtained by simultaneous hydrolyzing, and which is better than sequential hydrolyzing.For A+C, sequential hydrolyzing of A followed by C gave the highest DH of 36.56%. For B+C, B and C in sequence gave the biggest DH of 34.56%. Hence it can be concluded that all 3 combinations increased the DH value significantly.