In-vitro angiotensin converting enzyme (ACE), antioxidant activity and some functional properties of silver catfish (Pangasius sp.) protein hydrolysate by ultrafiltration

Abstract

The aim of this study was to investigate the bioactivity and functional properties of silver catfish (Pangasius sp.) muscle protein hydrolysate (SCMH) at different molecular size (3, 5 and 10 kDa) via ultrafiltration membrane. Bioactivity measures included angiotensin-converting enzyme (ACE) inhibitory activity and antioxidant activity (DPPH radical-scavenging activity, reducing power and Fe2+ chelating effects). The functional properties examined included emulsifying, foaming and solubility. There were significant differences (p < 0.05) in ACE inhibitory activity among the SCMH fractions, with the <3 kDa SCMH fraction showing the highest ACE inhibitory activity (87.68%). There were significant differences (p < 0.05) in DPPH radical-scavenging activities, reducing power and Fe2+ chelating effects among the different SCMH fractions. Fraction <3 kDa showed the highest DPPH radical-scavenging activities and reducing power, while fraction <10 kDa showed the highest chelating effect among all fractions (p < 0.05). In addition, there were no significant difference (p > 0.05) among all SCMH fractions in the emulsifying activity index. However, there were significant differences in terms of emulsifying stability index and foaming capacity properties (p < 0.05). Moreover, there was a significant difference (p > 0.05) among the SCMH fractions in terms of solubility. In conclusion, variations in the molecular size of the SCMH fractions showed a variety of potential applications for silver catfish protein hydrolysates in functional foods, as it possessed high bioactivity and good functional properties.