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 w ithout tocopherols, to laying hens was investigated on oxidative stabi lity of cholesterol in egg yolk powders. Storage of spray-dried egg yo lk powders at room temperature resulted in loss (p<0.05) of tocopherol s. The initial levels of spray-dried yolk cholesterol oxides were 7-10 ppm and increased (p<0.05) with storage. The cholesterol oxide conten ts in the egg yolk powders were: fish > flax > sunflower > palm. Heati ng 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.