Comparison between the effect of γ-irradiation and roasting on the profile and antioxidant activity of wheat germ lipids.

Abstract

In order to utilize wheat germ, a nutrient-dense byproduct of the wheat milling industry, in various food products, different treatments are used to investigate and stabilize its influence on lipid characteristics. However, there are no reports on the effect of γ-irradiation on the lipid profile of wheat germ. In this study, the impact of γ-irradiation (at radiation doses 1/4, 1/2 and 1 kGy) and roasting at (160 °C for 20 min) on the lipid constituents of wheat germ was examined. Both thermal and irradiation treatments did not have a significant effect on the total lipid recovery or the fatty acid composition of wheat germ lipids. The fatty acid profile was found to be made up of linoleic followed by oleic and palmitic as the major fatty acids. An increase in the content of free fatty acids characterized the lipid profile of the irradiated wheat germ samples. Antiradical properties of lipids from roasted and irradiated samples were analyzed using the bleaching of the stable 1,1-diphenyl-2- picrylhydrazyl radical (DPPH). Lipids from irradiated samples exhibited relatively stronger radical scavenging potential than lipids from roasted wheat germ. It has been concluded that γ- irradiation could be applied for wheat germ preservation, where it might be limited to a dose of 1/4 kGy in the processing.