Effect of low-energy X-ray/high-energy gamma-ray combined with modified atmosphere packaging and encapsulated nanoemulsion on microbiological and physicochemical properties of seasoned ground beef

This study investigated the antimicrobial effects of different treatments on seasoned ground beef during chilled storage. The treatments included low-energy X-ray and high-energy gamma-ray (γ-ray) irradiation at 1.5 kGy, encapsulated nanoemulsion (NE), and modified atmosphere packaging (MAP; 80 % O2 + 20 % CO2), applied individually and in combination. Both irradiation methods exhibited potent antimicrobial activity, significantly reducing total viable counts, lactic acid bacteria, and Brochothrix thermosphacta, while Pseudomonas spp. was not detected in any irradiated samples throughout the shelf-life, indicating high irradiation sensitivity. The combined treatments extended the shelf-life of ground beef up to 27-30 days compared to the control (9-12 days), demonstrating a synergistic effect. Additionally, the combined treatments preserved the color quality and oxymyoglobin content, while reducing lipid oxidation and minimizing the oxidative impacts typically associated with irradiation. Interestingly, X-ray irradiation, despite its lower penetration ability compared to γ-rays, proved to be equally effective in extending the shelf-life of ground beef. Physicochemical analysis showed that X-ray irradiation maintained better color preservation and reduced fat oxidation. Thus, this study highlights the potential of combining X-ray irradiation with encapsulated NE and MAP as an innovative and effective approach for enhancing microbiological safety without compromising ground beef quality, offering a sustainable solution for shelf-life extension.