Structure elucidation of ACE‐inhibitory and antithrombotic peptides isolated from mackerel skin gelatine hydrolysates

Abstract

BACKGROUND:The fish-processing industry generates significant amounts ofwaste and by-products that are usually discarded. This study investigated the preparation of bioactive gelatine peptides from fish skin. Gelatine was extracted from mackerel (Scomber scombrus) skin and hydrolysed by pepsin for 1, 2, 6 and 24 h. All hydrolysates were screened for antioxidant, ACE-inhibitory and antithrombotic activities. RESULTS: Gelatine peptides obtained after 24 h of hydrolysis exhibited the highest antioxidant activity (DPPH reduction ∼80%, FRAP ∼130 μmol Trolox equivalent L−1). These hydrolysates had high ACE-inhibitory activity (>70%) and were able to significantly (P < 0.05) inhibit platelet aggregation by about 30%, corresponding to moderate antithrombotic activity. CONCLUSION: The bioactive properties were mainly due to the presence of low-molecular-weight peptides of 337 and 423 Da.