Optimization of Gelatin Extraction Process, from Sheep Skin Waste Uing Alcalase Enzyme by Response Surface Method

This study determined the optimal conditions for enzyme-assisted gelatin extraction from sheep skin waste using the effects of three variables: enzyme concentration (0.5-2.5%), hydrolysis time (60-240 min), and extraction temperature (60-80 °C). The impact of these three variables was studied on extraction, yield, gel strength, viscosity, degree of hydrolysis, melting point and SDS-PAGE, and the results were analyzed by using the central composite design (CCD) and response surface methodology (RSM). Also the analysis of variance table showed that the lack of fit was not significant for all response surface models at 95%. The results showed that enzyme concentration 0.5%, hydrolysis time of 166 min, and extraction temperature 60 °C are the desirable condition for optimal extraction (11.03%) and optimal degree of hydrolysis (23.00%). In addition, the effects of these three variables on gel strength, viscosity and melting point were significant, and in optimal conditions, gel strength was measured as 175.33 g, viscosity as 3.26 Mpa/sec, and melting point as 25.39 °C.