Document Type : Original Article
Department of Fisheries, Faculty of Natural Resources and Marine Sciences, Tarbiat Modares University, Noor, Iran
Department of Food Science, Sari Agricultural Sciences and Natural Resources University, Sari, Iran
The optimum conditions for gelatin extraction from whitecheek shark Carcharhinus dussumieriskin have been determined by response surface methodology (RSM). The experiment optimization has been conducted by central composite design (CCD), using NaOH concentration (0.01-1 N), HCl concentration (0.01-1 N), and extraction time (3-8 h) as independent variables, and gelatin protein content (%) and viscosity (mPa.s) as dependent variables. The results showed that the NaOH and HCl concentrations had significant effect on crude protein content and viscosity of whitecheek shark skin gelatin (p < /em> < 0.05). Whereas, extraction time up to 8 h had no significant effect on these two properties (p < /em> > 0.05). Optimum extraction conditions have been found at 0.92 N NaOH concentration, 0.01 N HCl concentration, and 5.45 h extraction time with 93.1 (%) protein content, and 10.21 (mPa.s) viscosity of the extracted gelatin. The P-value of lack of fit for viscosity was 0.9356 and total regressions P-value was 0.0028 and for protein content were 0.0501 and 0.0346, respectively.