Antibacterial effect of ultrasound and β-citronellol against Listeria monocytogenes and its application in carrot preservation

[Display omitted] •US combined with β-citronellol (US + CT) had a synergistic effect on the inactivation of Listeria monocytogenes.•US + CT caused an increase in ROS levels and extracellular MDA content of L. monocytogenes.•US + CT severely disrupted cell membrane integrity, permeability and cell morphology.•US + CT significantly reduced the populations of L. monocytogenes on the carrot surface.•US + CT did not affect the color of the carrots but reduced the moisture and hardness of carrots. This study investigated the antibacterial effects of ultrasound (US), β-citronellol (CT), and a combination of the two treatments on Listeria monocytogenes. Results showed that US or CT alone did not show apparent antibacterial effect (0.02–0.76 log CFU/mL reduction). The combined treatment showed obviously inactivate effect of L. monocytogenes, the populations of L. monocytogenes decreased by 8.93 log CFU/mL after US (253 W/cm2, 20 kHz) + 0.8 mg/mL CT treatment. US + CT treatment also had a significant (P 0.05) change the surface color of carrots but significantly (P