Preparation Technology of Antihypertensive Peptides Using Alcalase in Hydrolyzates of Loach Protein

Three indices(the degree of the angiotensin Ⅰ-converting enzyme(ACE) inhibitory activity,the degree of hydrolysis(DH) and the yield of peptide) of loach meat hydrolysates hydrolyzed by five different hydrolytic enzymes(alkali protease,alcalase,Bromelain,Trypsin and nematolyt) were evaluated.Alcalase was chosen as the optimal hydrolysis enzyme.On the basis of single factor experiment,response surface was used to optimizing the hydrolysate conditions.The result showed that the optimal enzymatic hydrolysis condition that could produce the protein hydrolysates with the highest activity on angiotensin-converting enzyme inhibitory activity hydrolyzed by alcalase was as follows: time 60 min,pH 8.1,temperature 45 ℃,(E/S)1 900 U/g,and substrate concentration 1∶15.Under such a condition,the IC50 of the ACE inhibitory peptides were 0.22 mg/mL.