Synergistic antimicrobial effect of X-ray and curcumin against Listeria monocytogenes on sliced cheese.

The objectives of this study were to investigate the antimicrobial effect of the X-ray and curcumin combination against Listeria monocytogenes on sliced cheese and to determine the effect of this treatment combination on the quality attributes of sliced cheese. Treatment with the combination of X-ray (0.4 kGy) and curcumin (0.5 mg/L) resulted in the reduction of L. monocytogenes cell count by 3.65 log CFU/g. The synergistic cell count reduction of L. monocytogenes in the combination treatment group was 0.92 log units. The underlying antimicrobial mechanisms of X-ray and curcumin combination include enhanced generation of intracellular reactive oxygen species (ROS) in bacterial cells and bacterial cell membrane damage. However, the combination treatment group did not exhibit intracellular enzyme inactivation. There was no significant (P > 0.05) difference in the color, texture, and sensory attributes of the sliced cheese between the combination treatment and control groups. These results demonstrate that the combination treatment with X-ray and curcumin is a potential alternative strategy for inactivating L. monocytogenes on ready-to-eat food products without affecting their quality. • Combination of X-ray and curcumin exerts a synergistic antimicrobial effect against L. monocytogenes. • Enhanced ROS generation and cell membrane damage were the main antimicrobial mechanism. • Combination treatment did not adversely affect the sliced cheese quality. [ABSTRACT FROM AUTHOR]