Evaluation of Processing Methods on Quality and Oxidative Stability of Ghee

Abstract

Four ghee samples two of them were traditionally processed purchased from Khartoum North (T1) and the other processed at home (T2) and other two commercial brands (Aseel and Haloob) were examined for physicochemical properties, quality, oxidative stability and sensory evaluation. The traditionally processed samples showed low peroxide value (1.5 and 2.0 mEq O2/kg) and free fatty acid (0.61 and 0.60%) for T1 and T2, respectively in comparison to commercial brand samples peroxide value (2.5 for Aseel and Haloob) and free fatty acids (1.29 and 1.27) for Aseel and Haloob, respectively. No difference in the specific gravity of all samples which is 0.90 while there is a significant differences (P≤0.05) among all samples concerning the color Y/R (5.9/1.3, 5.8/1.3, 7.3/1.5 and 15.5/1.7) for T1, T2, Aseel and Haloob, respectively. Concerning refractive index Aseel (1.4658) and Haloob (1.4670) showed higher RI than T1 (1.4627) and T2 (1.4617). The major fatty acids of the four ghee samples, as determined by GC/MS, were palmitic, stearic, oleic, lauric, myristic and capric acid, and no unusual fatty acids were found. Traditionally processed samples T1 and T2 showed higher stability during excessive storage at 70°C for 72 hours than factory processed samples. The sensory evaluation results obtained by the panelists showed a significant difference (P≤0.05) among the average scores for color, odor and taste of the four ghee samples and T 2 was most acceptable by the panelists. The panelists ranked traditionally processed samples first followed by commercial brands ones.