Cholesterol oxidation in egg yolk powder during storage and heating as affected by dietary oils and tocopherol

The effects of feeding flax, sunflower, palm and fish oils, with and without tocopherols, to laying hens was investigated on oxidative stability of cholesterol in egg yolk powders. Storage of spray-dried egg yolk powders at room temperature resulted in loss (p<0.05) of tocopherols. The initial levels of spray-dried yolk cholesterol oxides were 7-10 ppm and increased (p<0.05) with storage. The cholesterol oxide contents in the egg yolk powders were: fish > flax > sunflower > palm. Heating egg yolk powder increased (p<0.05) the amounts of total cholesterol oxides. Diets with tocopherol supplementation resulted in a decrease (p<0.05) of cholesterol oxides during storage and heating.