Abstract:

Pepsin-soluble collagens (PSCs) were extracted from fish scales of grass carp, bighead carp, bream carp and crucian carp. The effects of three pre-treating media on structure of PSC from grass carp were studied by FT-IR spectroscopy. Then PSCs from fish scales of the fours species of carp were analyzed for physical and chemical properties. HCl and Na2CO3 had great destruction effects on the structure of grass carp scale PSC. The denaturalization temperatures of PSCs from fish scales of grass carp, bighead carp, bream carp and crucian carp were measured using an Ostwald viscometer to be 33.0, 31.9, 31.5, and 30.8 ℃, and the Hyp contents were 7.75, 44.91, 39.59, and 40.36 mg/g, respectively. SDS-PAGE analysis indicated that molecules of grass carp scale PSC contained three alpha chains ( α1, α2 and α3) while only two alpha chains ( α1 and α2) were observed in molecules of the other three PSCs. FT-IR spectra showed that there were few differences in the structure of the PSCs. All the four PSCs proved to belong to the type I collagen family and be of electrophoretic purity.

Key words: freshwater fish scales, PSC, SDS-PAGE, FT-IR