Functional and Antioxidant Properties of Gelatin Hydrolysates Prepared from Skin and Scale of Sole Fish

Abstract

Preparation of bioactive hydrolysates is an efficient approach for developing high value industrially important products from fishery waste. In this study, gelatin hydrolysates were prepared from skin and scale of sole fish and evaluated for functional and antioxidant properties. Hydrolysis of extracted gelatin solution with alcalase enzyme for 2 h yielded 16.42 per cent skin gelatin hydrolysates (SGH) and 8.44 per cent scale gelatin hydrolysates (SCGH) with 23.6 and 18.57 per cent degree of hydrolysis, respectively. Quantity of proximate components including protein, fat, ash, and moisture of the two hydrolysates did not differ significantly. SCGH displayed significantly higher foaming capacity and foam stability index compared to SGH. Emulsion activity index was significantly higher with SGH, whereas emulsion stability index was higher for SCGH. 2,2, diphenyl 2 picryl hydrazine (DPPH) free radical scavenging activity, metal reducing power, and metal chelating ability was found to be higher with SCGH than SGH; however, the values were not significantly different with respect to metal chelating activity and reducing power.