Study On The Processing Technology Of Chicken Bone Peptides And Its Inhibitory Activity To ACE

Chicken bone is the main by-product of chicken slaughtering and processing.In order to explore new ways to use chicken bone and promote the high added value of chicken bone,the preparing technology and ACE inhibitory activity of chicken bone peptides were investigated systematically in this paper ,which can provide theory basis for the industrialization of chicken bone peptides .The various parameters of hydrolysis process were optimized. Alcalase was chosen as the tool to hydrolyze chicken bone protein. The better factors optimized by Single factor experiment were as following: Alcalase dosage 5937.5U/g, substrate concentration 4%, pH values 8.0～8.5, temperature 55℃, time 120min.Under these conditions,The DH of chicken bone protein was 15.9%, and TCA-NSI was 61.81%.The regression models were established between the indexes, including TCA-NSI and ACE inhibitory activity of chicken bone peptides, and the factors that affect the preparation of chicken bone peptides by orthogonal rotation design. When ACE inhibition rate of the chicken bone peptide was chosen as the first experimental index, The factors were optimized as following: substrate concentration 4%, time 210min, Alcalase dosage 10937.5u/g, temperature 55℃. While ACE inhibition rate was 75.74%, and which TCA-NSI was 60.47% was proved by experiment under the condition. When TCA-NSI as the first experimental index, The factors were optimized as following: substrate concentration 4%, time 120min, Alcalase dosage 8910.5u/g, temperature 55℃. Under these conditions, The highest value of TCA-NSI was 65.79%, and which ACE inhibition rate was 71.42% was proved by experiment under the condition.ACE inhibitory peptides were separated by ultra-filtration technology,and the best conditions of the ultra-filtration were as following :Intercept molecular weight 5ku, Pressure 0.18MPa,Temperature 20℃and 5～7.5% peptides. The recovey rate of chicken bone peptides below 5ku was 17.80%, after separation with ultra-filtration. ACE inhibitory peptides were purified by ultra-filtration technology, of which IC50 value reduced form 2.97 mg/ml to 0.73 mg/ml. ACE inhibitory activity increased greatly. It showed that ultra-filtration played a role of enrichment and purification in ACE inhibition components of chicken bone peptides.The functional activities of chicken bone peptides were studied preliminarily. the results showed that chicken bone peptides had significant ACE inhibitory activity and antioxidative activity,and chicken bone peptides belonged to competitive inhibition to ACE, and ACE inhibitory activity of chicken bone peptides were positively correlated to the contents of hydrophobic, aromatic and branched-side chains amino acids.