title: Combined effect of ultrasound and essential oils to reduce Listeria monocytogenes on fresh produce.
abstract: Salads prepared from contaminated fresh produce have a high risk of causing food-borne illnesses. Essential oils obtained from plants have antimicrobial activity and may provide a natural approach to reduce the pathogens on fresh produce. Additionally, ultrasound treatments have been shown to reduce the microbial counts on different foods. The objective of this study was to investigate the antimicrobial activities of cinnamon and lemon essential oils in vitro and in food applications. Mixtures of lettuce, parsley and dill were inoculated with Listeria monocytogenes and then dip-treated for 5 min in one of the following treatments: sterile tap water, chlorinated water, 1% lemon essential oil, 2% cinnamon essential oil or 2% cinnamon essential oil + ultrasound. The samples were stored at 4 ℃ and collected at d 0, 1, 3, 5, 7 and 9 post inoculation. The 1% lemon (4 log) and 2% cinnamon (2 log) essential oil washes provided partial inhibition against L. monocytogenes by d 1. The combined application of 2% cinnamon oil and ultrasound resulted in only 0.85 log inhibition by d 1; however, the number of L. monocytogenes increased during storage and became nearly equal to the control at d 9. Therefore, different combinations of essential oils with other antimicrobials or novel technologies are required.
authors.affiliation: Department of Biology, Faculty of Science and Literature, Çanakkale Onsekiz Mart University, Turkey.
authors.forename: Gülçin
authors.initials: G
authors.lastname: Özcan
authors.affiliation: Department of Food Engineering, Faculty of Engineering, Çanakkale Onsekiz Mart University, Turkey dnukhet@hotmail.com.
authors.forename: Nükhet Nilüfer
authors.initials: NN
authors.lastname: Demirel Zorba
mesh_terms: D000890:Anti-Infective Agents / Q000032:analysis / Q000494:pharmacology; D015169:Colony Count, Microbial; D003666:Decontamination; D005506:Food Contamination / Q000517:prevention & control; D005511:Food Handling; D005516:Food Microbiology; D059022:Food Safety; D018545:Lactuca / Q000382:microbiology; D008089:Listeria monocytogenes / Q000187:drug effects*; D008826:Microbial Sensitivity Tests; D009822:Oils, Volatile / Q000032:analysis / Q000494:pharmacology*; D010938:Plant Oils / Q000032:analysis / Q000494:pharmacology; D011786:Quality Control; D014465:Ultrasonics; D014675:Vegetables / Q000382:microbiology*
chemical_list: D000890:Anti-Infective Agents; D009822:Oils, Volatile; D010938:Plant Oils; C510046:cinnamon oil, bark; C501365:lemon oil
keywords: Fresh produce; Listeria monocytogenes; cinnamon oil; lemon oil; ultrasound