Optimization of gelatin extraction from Thai fish panga (Pangasius bocourti sauvage) skin

Abstract

An investigation on optimal conditions for gelatin extraction from the Thai fish panga (Pangasius bocourti Sauvage) skin was performed by response surface methodology. A Box-Behnken design was applied to examine the effects of extraction temperature (40-70°C), pH (3.7-7.4) and extraction time (1-5 h) on gelatin yield, gel strength and gel colour. All regression models were significant (P≤0.01) and lack-of-fit of the models was insignificant, except for that of the gel strength. The Anderson-Darling normality test of the standardized residuals showed adequacy of all models. The optimal conditions for gelatin extraction were at 55°C, pH 4.55 for 1 h. The predicted responses were 20.22% gelatin yield, 506.55 g gel strength, 42.22 lightness (L*), 3.56 chroma (C*) and 43.35° hue angle (h°). The experimental responses of gelatin extracted at the optimal conditions were not significantly different (P>0.5) from the predicted value.