title: In-package inhibition of E. coli O157:H7 on bulk Romaine lettuce using cold plasma.
abstract: Dielectric barrier discharge atmospheric cold plasma (DACP) treatment was evaluated for the inactivation of Escherichia coli O157:H7, surface morphology, color, carbon dioxide generation, and weight loss of bulk Romaine lettuce in a commercial plastic clamshell container. The lettuce samples were packed in a model bulk packaging configuration (three rows with either 1, 3, 5, or 7 layers) in the container and treated by DACP (42.6 kV, 10 min). DACP treatment reduced the number of E. coli O157:H7 in the leaf samples in the 1-, 3-, and 5-layer configurations by 0.4-0.8 log CFU/g lettuce, with no significant correlation to the sample location (P > 0.05). In the largest bulk stacking with 7 layers, a greater degree of reduction (1.1 log CFU/g lettuce) was observed at the top layer, but shaking the container increased the uniformity of the inhibition. DACP did not significantly change the surface morphology, color, respiration rate, or weight loss of the samples, nor did these properties differ significantly according to their location in the bulk stack. DACP treatment inhibited E. coli O157:H7 on bulk lettuce in clamshell containers in a uniform manner, without affecting the physical and biological properties and thus holds promise as a post-packaging process for fresh and fresh-cut fruits and vegetables.
authors.affiliation: United States Department of Agriculture, Eastern Regional Research Center, 600 Mermaid Lane, Wyndmoor, PA 19038, USA; Department of Food Science and Technology, Seoul Women's University, 621 Hwarangro, Nowon-gu, Seoul 139-774, Republic of Korea.
authors.forename: Sea C
authors.initials: SC
authors.lastname: Min
authors.affiliation: United States Department of Agriculture, Eastern Regional Research Center, 600 Mermaid Lane, Wyndmoor, PA 19038, USA; Department of Food Science and Technology, Seoul Women's University, 621 Hwarangro, Nowon-gu, Seoul 139-774, Republic of Korea.
authors.forename: Si Hyeon
authors.initials: SH
authors.lastname: Roh
authors.affiliation: United States Department of Agriculture, Eastern Regional Research Center, 600 Mermaid Lane, Wyndmoor, PA 19038, USA. Electronic address: Brendan.Niemira@ars.usda.gov.
authors.forename: Brendan A
authors.initials: BA
authors.lastname: Niemira
authors.affiliation: United States Department of Agriculture, Eastern Regional Research Center, 600 Mermaid Lane, Wyndmoor, PA 19038, USA.
authors.forename: Glenn
authors.initials: G
authors.lastname: Boyd
authors.affiliation: United States Department of Agriculture, Eastern Regional Research Center, 600 Mermaid Lane, Wyndmoor, PA 19038, USA.
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Sites
authors.affiliation: United States Department of Agriculture, Eastern Regional Research Center, 600 Mermaid Lane, Wyndmoor, PA 19038, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Uknalis
authors.affiliation: United States Department of Agriculture, Eastern Regional Research Center, 600 Mermaid Lane, Wyndmoor, PA 19038, USA.
authors.forename: Xuetong
authors.initials: X
authors.lastname: Fan
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology; D001274:Atmospheric Pressure; D015169:Colony Count, Microbial; D019453:Escherichia coli O157 / Q000187:drug effects*; D005516:Food Microbiology / Q000379:methods*; D018857:Food Packaging; D005517:Foodborne Diseases / Q000382:microbiology / Q000517:prevention & control; D006801:Humans; D018545:Lactuca / Q000378:metabolism / Q000382:microbiology*; D018515:Plant Leaves / Q000382:microbiology; D058626:Plasma Gases / Q000494:pharmacology*
chemical_list: D000890:Anti-Infective Agents; D058626:Plasma Gases
keywords: Cold plasma; E. coli O157:H7; Lettuce; Nonthermal treatment