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 (Cynoglossus arel) and evaluated for functional and antioxidant properties. Hydrolysis of extracted gelatin solution with alcalase enzyme for 2 h yielded 16.42% (weight yield) skin gelatin hydrolysates (SGH) and 8.44% scale gelatin hydrolysates (SCGH) with 23.6 and 18.57% degree of hydrolysis, respectively. Quantity of proximate components including protein, fat, ash, and moisture of the two hydrolysates did not differ significantly (p > 0.05). SCGH displayed significantly higher (p < 0.05) foaming capacity (54%) and foam stability index (42%) compared to SGH (36 and 34%, respectively). Emulsion activity index was significantly higher with SGH (112.6 m²/g), whereas emulsion stability index was higher for SCGH (15.5 min). 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.

Pangasianodon hypophthalmus (sutchi catfish) is a fresh water catfish extensively being cultured in the South East Asian countries in the recent years. The present study provides the first report on the effects of gutting on the quality characteristics of aquacultured sutchi catfish stored in ice. pH of whole ungutted and gutted catfish didn’t show significant difference (p > 0.05) during ice storage period. Total Volatile Base Nitrogen (TVB-N), Alpha Amino Nitrogen (AAN), Free Fatty Acids (FFA) and Thio Barbituric Acid Reactive Substance (TBARS) were lower in gutted fish compared to whole ungutted fish at any particular day during ice storage. However, gutted fish expressed higher rate of primary lipid oxidation than ungutted fish. Textural degradation of the fish muscle as indicated by hardness, cohesiveness, springiness and chewiness was lower in gutted fish. Results of sensory evaluation revealed that gutting has significantly improved the sensory quality of the fish. However, microbiological analysis revealed higher Total Plate Count (TPC) and Enterobactereaceae count in gutted fish. The shelf life of gutted and whole ungutted sutchi cat fish as determined by microbiological analysis was 16–18 days and 18–20 days respectively while storage in ice.