Studies on the nutritional value of foods treated with γ‐radiation. II.—effects on the protein in some animal feeds, egg and wheat

The effect of γ‐radiation on the protein nutritive value of certain animal feeds (protein concentrates), frozen whole egg, whole wheat and wheat gluten was measured by use of a microbiological method. There was little change in nutritive value of the animal feeds with doses of 0·5 and 1·0 Mrad and no change with frozen egg at.0·5 and 5·0 Mrad. Whole wheat showed no loss at 0·2 Mrad; a 6% loss at 1·0 Mrad was not increased further at 5·0 Mrad. Gluten prepared from wheat and then irradiated was unchanged at 0·02 Mrad but losses of 5, 7 and 26% were shown with doses of 0·2, 1·0 and 5·0 Mrad respectively. Following amino‐acid supplementation studies and microbiological assays for methionine, loss of availability of this amino‐acid was demonstrated to be principally responsible for the lowering of the nutritive value of the 5·0‐Mrad‐irradiated wheat gluten.