Antimicrobial efficacy of linalool and cinnamaldehyde against Salmonella Infantis: Synergistic and antagonistic interactions with food components

Abstract

The objective of this study was to evaluate the antimicrobial ability of linalool and cinnamaldehyde and to investigate the effect of food components on their efficacy. Food components assessed in this study included sodium chloride, glycine, sucrose, ethanol, acetic acid, and lactic acid. The influence of varying concentrations of linalool or cinnamaldehyde, in combination with food components, on their antimicrobial efficacy against Salmonella Infantis was investigated using the checkerboard method and Weibull model, and was validated in beef broth and lettuce food model media. Flow cytometry analysis and transmission electron microscopy were used to examine morphological and biological changes of S. Infantis. The combination of 0.95 g/L linalool and 34 g/L sodium chloride showed the most significant synergistic interaction, while the combination of 0.84 g/L cinnamaldehyde and 1.05 g/L acetic acid exhibited the most significant antagonistic interaction. The study found that sodium chloride intensified the damaging effect of linalool on bacterial cell membranes, leading to faster cell inactivation, whereas acetic acid alleviated the damage to cell membranes, thereby reducing cinnamaldehyde's efficacy. This study investigated the antimicrobial efficacy of linalool and cinnamaldehyde and provided insights into their appropriate use in food by analyzing their interactions with food components.