Antioxidant activity of protein hydrolysate from snakehead fish (Channa striata) viscera obtained by enzymatic process

Abstract

Snakehead fish (Channa striata) in South Sumatra, Indonesia has been widely used as a raw material in the processing of typical Palembang food industry, namely pempek, kemplang, and kerupuk. During its processing, not all parts of the fish can be utilized. In general, only 40% of the fish is used for consumption and 60% is wasted as by-products. One of the by-product produced during processing is viscera which can still be used as value-added products. One alternative is to use viscera as raw material in the production of fish protein hydrolysate (FPH) which is well known to have functional properties such as antioxidant, antibacterial, antihypertensive, and anticancer. This research was aim to determine the antioxidant activity of FPH made from snakehead fish viscera as a source of natural antioxidants. The research was conducted by papain treatments with the concentration of enzymes used were 1%, 2% and 3%. Evaluation of the hydrolysis process was done by measure the soluble protein and DH (degree of hydrolysis) while antioxidant activity was carried out by DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2,2-Azinobis 3-ethyl benzothiazoline6-sulfonic acid) assay. DH of fish protein hydrolysate was found to be 68.79%, 77.06% and 72.63%, respectively while protein solubility gave values of 5.69%, 6.15% and 6.56% respectively. The highest antioxidant activity was attained at enzyme concentration of 3% with DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2,2-Azinobis 3-ethyl benzothiazoline 6-sulphonic acid) value were 37.26% and 58.58% respectively.