Profiling of antioxidative proteolysate enzymatically hydrolysed from stone fish (Actinopyga lecanora)

Abstract

Marine livings represent one of the richest sources of protein with valuable bioactives. The present work explores the antioxidative potential of stone fish, a sea cucumber species typically discarded as by-catch. Stone fish was enzymatically hydrolysed using papain, and the resulting proteolysate exhibited strong antioxidant activity in DPPH• radical scavenging (IC50 = 0.49 mg/mL), ABTS• (IC50 = 0.36 mg/mL) radical scavenging, and FRAP value (0.29 mM FeSO4) after 8 h of hydrolysis. Fractionation of proteolysate was then performed using three approaches namely ultrafiltration, reversed-phase high performance liquid chromatography, and isoelectric focusing techniques to profile and characterise the antioxidative proteolysate. Results indicated that papain-generated proteolysate from stone fish flesh possessed considerable amount of antioxidative peptides with molecular weight of approximately 2 kDa, low hydrophobicity (< 20%), and pI = 9.