Preparation of antioxidative peptides from Spanish mackerel (Scomberomorus niphonius) processing byproducts by enzymatic hydrolysis

Abstract

Marine fish processing byproducts were considered as potential good protein resource for producing bioactive peptides by enzymatic hydrolysis. In this study, preparation and partial characteristics of the antioxidative peptides from Spanish mackerel (Scomberomorus) processing byproducts fish frame by commercial proteases were investigated. The results showed that the mackerel frame hydrolysate with alcalase had the highest degree of hydrolysis and DPPH (1,1-diphenyl-2-pycryl-hydrazyl) radical scavenging activity, the values of 31.3 and 18.5%, respectively. The alcalase hydrolysate was ultrafiltrated into four fractions and the fraction with lower molecular weight had higher DPPH radical scavenging capacity. The fraction F4 with molecular weight less than 3 kDa had the highest DPPH radical scavenging capacity of 27.7%. The molecular weight distribution of fraction F4 showed that they were mainly consisted of less than 1 kDa small peptides and free amino acids. The small peptides in fraction F4 were mainly dipeptide to nonapeptide, especially tripeptide to hexapeptide.