Characteristics and functional properties of gelatin from seabass skin as influenced by defatting

Abstract

SummaryGelatins from nondefatted and defatted seabass skins were characterised and evaluated for their functional properties in comparison with commercial fish skin gelatin. All gelatins contained α1‐ and α2‐chains as the predominant components and showed a high imino acid content (199–201 residues/1000 residues). All gelatins had a relative solubility greater than 90% in the wide pH ranges (1–10). Foaming properties of all gelatins increased with increasing concentrations (1–3%, w/v). Gelatin from defatted skin had higher foam expansion and stability than that extracted from nondefatted skin. Emulsion containing gelatin from defatted skin had smaller oil droplet size (d32, d43), compared with that having gelatin from nondefatted skin (P < 0.05). After 10 days of storage at room temperature (28–30 °C), emulsion stabilised by gelatin from defatted skin showed the higher stability as indicated by the lower increases in d32 and d43, and lower flocculation factor and coalescence index. Coincidentally, emulsion stabilised by gelatin from defatted skin had higher zeta potential than that containing gelatin from nondefatted skin. Thus, defatting of seabass skin directly affected characteristics and functional properties of resulting gelatin.