Characteristics and functional properties of gelatin from zebra blenny (Salaria basilisca) skin

•Pepsin treatment of skin of zebra blenny increased the yield of gelatin extraction.•The gel strength of zebra blenny skin gelatin was 170.2 g.•The viscosity of zebra blenny skin gelatin was 5.95 cP.•Zebra blenny skin gelatin has excellent functional properties.•Zebra blenny skin gelatin showed strong ability of juice clarification.

Gelatin was extracted from alkali-pretreated skin of zebra blenny (Salaria basilisca) using commercial pepsin with a yield of 18 g/100 g of skin sample. The polypeptides pattern, gel strength, viscosity, textural parameters and functional properties of the zebra blenny skin gelatin (ZBSG) were investigated. Amino acid analysis revealed that ZBSG contained almost all essential amino acids, with glycine being the most predominant one. ZBSG was identified as a type I gelatin, containing α1 and α2-chains as the major constituents. Its gel strength and viscosity were 170.2 g and 5.95 cP, respectively. Fourier transformed infrared spectroscopy (FT-IR) spectra showed helical arrangements in its structure. Its solubility and functional properties were concentration-dependent. While foam expansion (FE) and foam stability (FS) increased with the increase of concentration, emulsifying activity index (EAI) and emulsion stability index (ESI) were noted to decrease. ZBSG also showed strong clarification ability particularly for apple juice, without affecting nutritional value.