Effects of gamma irradiated, cooked soy-, beef-, and soy/meat-based diets in rats, Ecology of Food and Nutrition, 38:5, There is increased demand for microbiologically safe foods. Ionizing energy (referred to as radiation pasteurization or irradiation) is effective in reducing the level of pathogenic organisms such as Salmonella, Trichinae, and Campylobacter which affect the health each year of many people. The irradiation of phytate (IP6), known to bind essential minerals in beef, soy, and soy-extended beef, at an absorbed dosage of less than 4 kilogray (kGy) caused no difference (P > 0.05) in the level of IP3-6 compared with non-irradiated samples. In a 3-wk study, 84 weanling rats (12 groups, 7 per group) consumed diets containing irradiated and non-irradiated soy, beef, and a soy-beef combination fed at 20% of the diet. There were no differences in liver and tibia mineral concentrations. * Corresponding author. 469 Downloaded by [University of Cambridge] at 03:42 02 June 2016 470 B.F. HARLAND ETAL.Moreover, there was no measurable effect on body weight, feed efficiency, survival of experimental animals, nor on any of the 4 blood or 7 biochemical parameters measured. In addition, the phytate:zinc and the [phytate xcalcium]:zinc molar ratios of the diets were calculated as an estimation of potential zinc deficiency. Microbiological tests, performed both before and after irradiation, on the soy-extended meat and meat patties used as dietary ingredients demonstrated a reduction in the bioload as a consequence of irradiation. Thus, irradiation at the dosage described above had no negative nutritional effects, was unable to enhance hydrolysis of phytate yet reduced the number of microorganisms in the animal food.
