Irradiation effects on meat: a review

Resumen

Food irradiation is a process exposing food to ionizing radiations such as gamma rays emitted from the radioisotopes ⁶⁰Co and ¹³⁷Cs, or, high energy electrons and X-rays produced by machine sources. Irradiation can induce formation of isooctane-soluble carbonyl compounds in the lipid fraction and acid-soluble carbonyls in the protein fraction of meat. Increasing irradiation dose increases these compounds however, cooking reduces them. Among the volatile components, 1-heptene and 1-nonene are influenced most by irradiation dose, and aldehydes (propanal, pentanal, hexanal) are influenced most by packaging type (aerobiose vs vacuum). Sulfur-containing volatiles formed from sulfur-containing compounds (primarily amino acids) also contribute to irradiation odor. Reducing the temperature during the irradiation process reduces the effects on odor/flavor because free radical generation and dispersion are reduced. Ultimately, radiolysis of water into free radical species may be the initiators of both lipid oxidation breakdown products and sulfur-containing volatiles responsible for irradiation odor. Methods to decrease the detrimental effects of irradiation include oxygen exclusion (vacuum packaging), replacement with inert gases (nitrogen) and addition of protective agents (antioxidants).