Abstract
Practical-type diets for chicks, guinea-pigs and cats, and a chick diet of purified ingredients, were assayed for their vitamin content before and after gamma-irradiation at doses ranging from 2 to 5 Mrad.
Irradiation of guinea-pig and chick diets resulted in small losses of vitamin A (in this investigation, 6 and 12 per cent respectively). Losses of vitamin E were larger (24 and 65 per cent) but were much less (11 per cent) when the diets were vacuum-packed before irradiation.
Vitamins were less stable in the purified chick diets, the most susceptible being vitamins A, E, B6 and thiamine. Vitamin destruction was greatly increased when antioxidants were incorporated into this diet, and also when its moisture content was high.
Vitamin A and β-carotene were almost completely destroyed in the cat diet, where there was also some loss of thiamine and folic acid.