Antibacterial properties and mechanism of 2-methoxycinnamaldehyde against Salmonella enteritidis and its potential application in treating raw pork

This study investigated the antibacterial activity and mechanism of action of 2-methoxycinnamaldehyde (MCA) against Salmonella enteritidis and evaluated the efficacy of MCA as a food disinfectant. The minimum inhibitory concentration (MIC) of MCA against S. enteritidis was 0.16 mg/mL. The acquired antimicrobial resistance toward MCA was weak, with low hemolytic activity and good in vitro stability. S. enteritidis exposed to MCA exhibited the formation of both holes and grooves on the cell surface, alterations in the structure and conformation of membrane proteins, leakage of nucleic acids, production of reactive oxygen species, membrane lipid peroxidation, binding to the groove of DNA, and destruction of protein secondary structures. After treatments with 1 MIC, 2 MIC, and 4 MIC of MCA for 20 min, S. enteritidis strain in pork slices was significantly inhibited ( p < 0.05), and the reduction amounts ranged from 1.31 to 4.98 log CFU/g. Additionally, the treated pork contained low levels of residual disinfectants and demonstrated high sensory acceptability. This study provides new insights into the antibacterial mechanism of MCA, which has broad application potential as a plant-derived antibacterial washing disinfectant to prevent foodborne pathogens. • We developed 2-methoxycinnamaldehyde as an antibacterial washing agent. • We identify the structural targets of 2-methoxycinnamaldehyde against Salmonella Enteritidis. • This is the first proof that hydrophobic small molecules can penetrate the phospholipid bilayer of bacterial cell membranes.