Effect of gamma irradiation on some characteristics of shell eggs and mayonnaise prepared from irradiated eggs

Shell eggs were irradiated at doses of 0.0, 0.5, 1.0 and 1.5 kGy of gamma irradiation. Immediately after irradiation, bacterial, physical and chemical analyses of eggs and sensory evaluation of the mayonnaise prepared from irradiated egg yolk were performed. Results indicated that all doses of gamma irradiation reduced the total counts of mesophilic bacteria and total coliforms of eggs. The radiation dose required to reduce the Salmonella load one log cycle (D-10) in eggs was 448 Gy. Eggs irradiated with 1.5 kGy may be suitable microbiologically to prepare safe mayonnaise. There were no significant differences in saturated fatty acids (C14:0; C16:0; C18:0) and thiobarbituric acidvalues between the yolk lipid extracted from irradiated eggs and that of nonirradiated ones. Gamma irradiation reduced the viscosity of egg whites. Sensory evaluation showed no significant differences between mayonnaises prepared from irradiated and nonirradiated egg yolks.