Physicochemical Properties and Amino Acid and Functional Group Profiles of Gelatin Extracted from Bovine Split Hide Cured by Acid

Abstract

Gelatin is natural substance obtained from the partial hydrolysis of collagen from animal skin, bones and connective tissue. This study examined the influence of acetic acid concentration on characteristics of gelatin extracted from bovine split hide. Bovine split hides were obtained from a local tannery and divided into three groups cured with 0.1, 0.3, or 0.5 M acetic acid for 24 h, followed by gradient extraction at 60, 70 and 80°C for 5 h each. Data were analyzed using a completely randomized design each treatment was replicated thrice. The results showed that the acetic acid concentration significantly affected the yield, ash content, pH and gel strength, but not the moisture, fat and protein content or viscosity of the resultant gelatin. Electrophoresis of gelatin proteins showed bands distribution between 25-40 kDa. The amino acid profile of the extracted gelatin was similar to that of collagen with a high level of hydroxyproline. Infrared spectroscopy showed the presence of O-H, C = O, C = C, C-H and C-O functional groups. The results suggest that gelatin extracted from bovine split hide cured with 0.5 M acetic acid provided the best physicochemical characteristics.