Chemical and Organoleptic Properties of Irradiated Dried Whole Egg and Egg Yolk

The influence of ⁶⁰Co gamma radiation on the chemical and organoleptic properties of solid whole egg and solid egg yolk has been studied to provide a basis for assessing the feasibility of the radicidation of Salmonella in egg powder. Irradiation up to 10 kGy did not produce measurable changes in acidity, vitamins B₁ or B₂. Radiolytic changes in the fatty component included the decomposition of triglycerides, the formation of hydroperoxides, and the degradation of carotenoids. An increase in hydroperoxidation with dose was coupled with a decrease in carotenoids and vitamin A. Radiolytic decomposition of various amino acids was not random, indicating that the secondary reactions of free radicals from the oxidized lipids were also significant in the selective damage to amino acids. The effects of both lipid and protein fraction could be minimized by irradiating in the absence of oxygen. The organoleptic properties of native egg solids, as well as scrambled eggs and mayonnaise prepared thereof, were indistinguishable from the samples irradiated in air up to 3 kGy, and from samples irradiated in the absence of oxygen up to 5 kGy.