Effects of enzymatic conditions on gelatin production from large animal raw hide

Abstract

This research aims to study the effects of enzymatic conditions (temperature, pH and time) on gelatin production on the yield of gelatin and gelatin properties such as gel strength and viscosity. The yield of gelatin is determined by Lowry method and the gelatin properties are determined from gelatin solution 12.5% wt. Two types of commercial enzymes were used in this work: papain and neutrase. In this study, raw hide was hydrolyzed by enzyme at various conditions. The temperature was varied in the range of 40-70 degree celsius and pH 6-8. From the results of gelatin recovery, it was found that at the beginning of the hydrolysis reaction, the percentage of gelatin recovery was sharply increased up to about 10 minute, then started to slightly increase. This was due to the low concentration of raw hide substrate which was the main factor controlling the reaction rate and the percentage gelatin recovery. The optimal ratio of papain per raw hide for highest gelatin recovery is 0.3:200. The optimum working conditions of papain are at 70 degree celsius and pH 6-7. For neutrase, the optimum working conditions are 40-50 C and pH 6-7. The percentage of recovered protein at optimal conditions is around 70-80%. From the results of gelatin properties, it was found that the gel strength and viscosity of gelatin from papain hydrolysis is relatively low, around 2.9-5.6 cP, comparing with Type A gelatin (food and laboratory grade). The protein recovered from neutrase hydrolysis can not from gel and the viscosity is very low (1.5-3 cP). So that papain is suggested to be used for the production of low gel strength gelatin while neutrase is suitable to be used for protein hydrolysate or collagen hydrolysate production.