Utilisation of collagenolytic enzymes from sierra fish (Scomberomorus sierra) and jumbo squid (Dosidicus gigas) viscera to generate bioactive collagen hydrolysates from jumbo squid muscle

Crude extracts of collagenases from jumbo squid (Dosidicus gigas) hepatopancreas and sierra fish (Scomberomorus sierra) viscera were used to hydrolyse squid muscle collagen into peptides with inhibitory capacity over angiotensin I-converting enzyme (ACE) and ABTS free radicals [2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid)], as a measure of their antihypertensive potential and antioxidant activity, respectively. Proteins from 20 to 200 kDa were found in both enzyme extracts; however, in comparison to the jumbo squid extract (JSE), the extraction yield and specific activity of the enzymatic sierra fish extract (SFE) were ≈ 40% greater, suggesting the presence of enzymes with different collagenolytic activity. Moreover, the utilised collagen was obtained with a yield of 0.98 ± 0.09 g/100 g muscle from jumbo squid arms, which after an incubation with JSE and SFE generated peptides with different biological activity. However, the collagen hydrolysates from the enzymatic SFE contained a higher proportion of low-molecular-weight peptides than that obtained from JSE (15.2 and 7.9% of < 3 kDa peptides, respectively). Finally, the antioxidant potential and ACE-inhibitory activity were increased after hydrolysis, being the SFE the one that showed a greater increase of both biological activities (82.28% of ACE inhibition and 64% of ABTS inhibition).