Physicochemical and microbial changes in Raw beef meat induced by radiation

This study aimed to investigate the effects of various electron beam irradiation doses on microbial inactivation and physicochemical properties of raw beef. The main research question was to determine the dose required to effectively eliminate pathogenic microorganisms without substantially compromising meat quality. Raw beef samples were treated with electron beam doses of 0, 1, 2, 3, 5, 7, and 9 kGy. Microbial inactivation was assessed by enumerating colonies of Salmonella Typhimurium, Listeria monocytogenes, Staphylococcus aureus, Bacillus cereus, and Escherichia coli. Based on the inactivation results, physicochemical properties—including proximate composition, water holding capacity, shear force, pH, color, thiobarbituric acid reactive substances, and volatile basic nitrogen—were evaluated after treatment with 0, 1, 2, and 3 kGy. Bacillus cereus was reduced below detection at 7 kGy, while other foodborne pathogens were eliminated at 3 kGy. No significant changes in proximate composition, pH, and shear force occurred compared to controls (p < 0.05). Water-holding capacity decreased significantly as the irradiation dose increased (p < 0.05), and redness increased in a dose-dependent manner. Although thiobarbituric acid reactive substances and volatile basic nitrogen tended to increase with increasing dose and storage time, these changes were not statistically significant. Electron beam irradiation at 3 kGy effectively inactivatied non-spore-forming foodborne pathogens while maintaining acceptable quality in raw beef. This dose can enhance microbial safety with minimal quality loss.