超声波协同双酶复合酶解米渣蛋白制备ACE抑制肽工艺研究

运用超声波协同双酶复合酶法水解米渣蛋白制备ACE抑制肽。超声波预处理后米渣蛋白水解物ACE抑制活性显著上升,碱性蛋白酶水解产物ACE抑制活性最强。通过单因素分析和响应面优化,得出最优水解条件为:超声功率1 000W,超声时间25min,酶解时间2.5h,料液比1∶8,加酶量3 000U/g。在此基础上复合中性蛋白酶水解,水解时间缩减至2.0h。水解产物通过超滤以及Sephadex G-25凝胶层析后,得到一分子量为338u,最强ACE抑制活性IC₅₀为116μg/ml组分P2。

Preparation of ACE inhibitory peptide using double enzyme hydrolysis assisted with ultrasonic from rice residue protein

Double enzyme hydrolysis assisted with ultrasonic was used to hydrolyze rice residue protein(RRP)to produce angiotensinⅠ-converting enzyme(ACE)inhibitory peptides.The ACE inhibitory effect was significantly improved when the RRP was pretreated with ultrasonic,and the ACE inhibitory activity of hydrolysates by alcalase was the highest.The hydrolysis conditions optimized by single factor experiment and response surface method were as follows:ultrasonic power 1 000 W,ultrasonic time 25 min,enzymatic hydrolysis time 2.5 h,the solid to liquid ratio 1∶8,and enzyme concentration 3 000 U/g.Pre-hydrolyzing RRP with neutrase resulted in the reduction of hydrolysis time to 2.0 h.The hydrolysate was then separated by ultrafiltration and Sephadex G-25 gel filtration.ACE inhibitory peptide(P2),which showed the highest ACE inhibitory activity(IC 50=116μg/ml)and a molecular weight of 338 u,was isolated.