Enzymatic hydrolysis of marine fish gelatin for producing ACE inhibitor peptides: meta-analysis

Bioactive peptides showing Angiotensin-I-Converting Enzyme inhibitory (ACEi) activity can control blood pressure. They can be produced from various protein sources, including fish gelatin. This article provides a systematic review and meta-analysis on gelatin extraction, conditions of enzymatic hydrolysis, characteristics of ACEi peptides, and effect of hydrolysis procedure on ACEi peptides. Fish gelatin preparation uses various solutions such as acids, bases and distilled water. Enzymatic hydrolysis is carried out with an E/S ratio of 0.2 – 7% and temperature of 28.9 oC (using bromelain) and 60.6 oC (using Alcalase). Level of pH in hydrolysis also varied greatly, from 2 (using Pepsin) to 10 (using Purafect enzyme). The molecular weight of fish gelatin ACEi peptides ranged from 186-829 Da and the sequence of peptides was dominated by hydrophobic and aliphatic amino acids. Based on a meta-analysis, hydrolysis using enzyme combination resulted in more satisfying product than a single enzyme, represented with a combined effect size value of 0.593.