Unraveling the mechanism of the synergistic antimicrobial effect of cineole and carvacrol on Escherichia coli O157:H7 inhibition and its application on fresh-cut cucumbers

作者：Addo, Keren Agyekumwaa; Li, Hui; Yu, Yigang^*; Xiao, Xinglong^*

来源：Food Control, 2023, 144: 109339.

DOI：10.1016/j.foodcont.2022.109339

• Cineole-carvacrol synergy
• Molecular docking
• Food preservative
• Escherichia coli O157
• H7

The objective of this study was to evaluate the mechanism of the synergistic antimicrobial effect of cineole (CN) and carvacrol (CR) on E. coli and its application on fresh-cut cucumbers. Herein, the CN/CR synergy could effectively inhibit E. coli by destroying its bacterial cell structure and causing the leakage of intracellular organic matters. For the first time, CN/CR synergy interaction on E. coli DNA and the possible mechanism of action on bacterial genetic material was revealed at the molecular level by molecular docking technology. Furthermore, CN/CR could significantly inhibit E. coli biofilm, mobility, and exopolysaccharides (EPS) production (p < 0.05). Supporting these findings, CN/CR suppressed E coli virulence genes shiga toxin (stx1), intimin (eae), flagella regulation (flhD), and AI-2 quorum-sensing gene (luxS) at transcriptional levels. Finally, CN/CR application at 1MIC+1MIC was satisfactory in significantly inhibiting E. coli on fresh-cut cucumbers but had a sensorial defect. Moreover, CN/CR at 1/2MIC+1/2MIC were generally acceptable with a better sensorial score. This study thus confirmed the CN/CR antimicrobial efficacy and maybe used as an alternative natural food sanitizer of fresh produce.