酶法制备火麻肽及其血管紧张素转化酶抑制活性研究

以火麻蛋白为原料,在碱性蛋白酶、中性蛋白酶、风味酶和木瓜蛋白酶4种单酶酶解火麻蛋白的基础上,再优选碱性+中性蛋白酶、碱性+风味酶、碱性+木瓜蛋白酶双酶分步对火麻蛋白进行酶解,酶解物(HPH)及其超滤组分的体外血管紧张素转化酶(ACE)抑制活性采用高效液相检测法(HPLC)进行测定。结果得到火麻蛋白最佳酶解组合为碱性+中性蛋白酶,最佳工艺条件为:碱性蛋白酶加酶量8000 U/g,pH10.0,酶解温度50℃,酶解时间4 h;中性蛋白酶加酶量8000 U/g,pH7.0,酶解温度45℃,酶解时间4 h,分步酶解物水解度(DH)和ACE抑制活性分别达74.52%和82.14%,但其与超滤各组分对ACE抑制活性差异并不显著。该研究为产业化制备火麻降血压肽提供理论依据。

Preparation of Cannabis sativa L.Peptides by Enzyme Method and Their Activities of Inhibiting Angiotensin Converting Enzyme

In this study,hempseed protein was firstly hydrolyzed by four enzymes(alcalase,neutral protease,flavourzyme and papain). Then,hemp seed protein isolate hydrolysis was stepwise hydrolyzed using three different proteases(alcalase+neutral,alcalase+flavourzyme and alcalase+papain). Angiotensin-converting enzyme(ACE)inhibitory activity of hemp seed protein hydrolysates and membrane ultrafiltration fractions was analyzed by HPLC. The results showed that the optimal stepwise hydrolyzed conditions of hemp seed protein were alcalase enzyme addition amount was 8000 U/g,the enzymolysis temperature was 50℃,the enzymolysis time was 4 h,the pH was 10 and neutral enzyme addition amount was 8000 U/g,the hydrolysis temperature was 45℃,the enzymolysis time was 4 h,the pH was 7.0. The degree of hydrolysis(DH)and in vitro ACE inhibitory activity were 74.52% and 82.14% respectively. However,there were not significant differences of ACE inhibitory activity between stepwise enzyme hydrolysis and membrane ultrafiltration fractions.It might be to provide theoretical basis for industrial preparation of anti-hypertensive peptides from hemp.