Abstract:Gelatin was extracted from grass carp (Ctenopharyngodon idella) scales under the conditions (60 ℃~80 ℃, 6 h) determined by single-factor tests. The physicochemical properties of gelatin extracted by the methods of gradient increasing temperatures (60 ℃~70 ℃~80 ℃)were studied, with gelatin extracted by constant temperature extraction method(60 ℃, 70 ℃ and 80 ℃) and commerical gelatin as control. SDS-PAGE showed that the gelatin obtained by gradient increasing temperature had a higher molecular weight (130~250 ku) and a higher gel strength than the commercial gelatin and the control group. FT-IR spectra showed that the gelatin obtained by the gradient increasing temperature had a typical amide band of gelatin. The sol-gel point and thermal denaturation temperature for the gelatin extracted by gradient increasing temperature were between 60 ℃ and 80 ℃, but the extraction rate and gel strength were relatively high, the ash content was less than 0.20%, and the fat content was less than 0.60%. In summary, the method of gradient increasing temperature can be used to extract gelatin with high extraction rate and good quality, and has a good application prospects.
