Nutritional Aspects of Food Irradiation: An Overview

Abstract

When foods are exposed to ionizing radiation under conditions envisioned for commercial application, no significant impairment in the nutritional quality of protein, lipid and carbohydrate constituents was observed. Irradiation was no more destructive to vitamins than other food preservation methods. Protection of nutrients is improved by holding the food at low temperature during irradiation and by reducing or excluding free oxygen from the radiation milieu. 'Deceased. Kennedy (1965) observed little change in nutritive value of animal feeds (protein concentrates) when 0.5 and 1.0 Mrad doses were appliedand no nutritional changes with frozen eggs irradiated at 0.5 and 5.0 Mrad. Ley (1972Ley ( , 1975 noted excellent results with radappertized feed for germ-free rat and mouse colonies which were maintained for 5 years. Radappertization and radicidation have been used in preference to thermal sterilization to sustain germ-free and specific-pathogen-free rats, mice, pigs and chickens (Sato 1970;Schoen and Hiller 1971;Udes et al. 1971;Ley et al. 1969;Coates et al. 1963). Others have reported that both the biological value of proteins, and the metabolizable energy value, of composite rodent diets are unaltered by radappertization a t 5.6 Mrad (Raica and Howie 1966;Read et al. 1961;Kraybill 1960).

Nutritional and other implications of irradiating meat

“…The protein efficiency ratio of irradiated and non-irradiated chicken stored at 5" for 4-7 d and then cooked also indicated that the 'nutritive value of the protein is not noticeably affected by the irradiation treatment of the chicken meat'. Moreover, in beef heated to inactivate enzymes and then sterilized with doses of 47-71 kGy, the concentrations of cystine, methionine and tryptophan, the three amino acids considered to be most sensitive to ionizing radiation, were not significantly affected by treatment even after storage for 15 months at room temperature (Josephson et al 1978).…”

Ionizing radiation effects on food vitamins: a review

“…Exposure to higher doses can cause destruction of this vitamin in direct proportion to dose raise (Ahmed, 1977). Retention of ascorbic acid in oranges, tangerines, tomatoes and papayas varied from 100% to 72% with 0.4 to 3.0 kGy doses (Josephson et al, 1978). Although most available data refer to irradiationinduced losses, especially of ascorbic acid in the reduced form, losses can actually be lower than reported, given that irradiation can convert ascorbic acid in reduced form into dehydroascorbic acid, biologically active form (Snauwart, 1973;Thomas, 1986).…”

“…Many studies on meat irradiation used sterilizing doses (20-40 kGy). Others, seeking directed to commercial application, used the doses lower than 10 kGy and showed that nutritive effects were not very different when compared to other preservation methods (Josephson et al, 1978). Meats are a great source water soluble vitamins from B complex.…”

“…Beef and pork sterilized by radiation retain more thiamin than thermosterilized products (Josephson et al, 1978)46. Thiamin loss rate is not associated to quantity of sulfidrils, protein, humidity, fat, pH or redox potential.…”

Radiação gama na conservação do suco natural de laranja

“…Estudos demonstram que, dentre as vitaminas hidrossolúveis, a C é a mais sensível à radiação (Josephson, 1978). No entanto, convém lembrar que, por ser uma vitamina relativamente lábil, resultados semelhantes de sua destruição ocorrem nos tratamentos de alimentos pelo uso do calor (Wiendl, 1984).…”