Extraction and characterisation of pepsin-solubilised collagen from fins, scales, skins, bones and swim bladders of bighead carp (Hypophthalmichthys nobilis)

The objective of this study was to extract and characterise pepsin-solubilised collagens (PSC) from the fins, scales, skins, bones and swim bladders of bighead carp and to provide a simultaneous comparison of five different sources from one species. The PSC were mainly characterised as type I collagen, containing two α-chains, and each maintained their triple helical structure well. The thermostability of PSC from the internal tissues (swim bladders and bones) was slightly higher than that of PSC from the external tissues (fins, scales and skins). The peptide hydrolysis patterns of all PSC digests using the V8 protease were similar. All PSC were soluble at acidic pH (1–6) and lost their solubility at NaCl concentrations above 30 g/l. The resulting PSC from the five tissues would all be potentially useful commercially.