title: Evaluation of chlorine dioxide gas treatment to inactivate Salmonella enterica on mungbean sprouts.
abstract: Although freshly sprouted beans and grains are considered to be a source of nutrients, they have been associated with foodborne outbreaks. Sprouts provide good matrices for microbial localization and growth due to optimal conditions of temperature and humidity while sprouting. Also, the lack of a kill step postsprouting is a major safety concern. The objective of this work was to evaluate the effectiveness of chlorine dioxide gas treatment to reduce Salmonella on artificially inoculated mungbean sprouts. The effectiveness of gaseous chlorine dioxide (0.5 mg/liter of air) with or without tumbling (mechanical mixing) was compared with an aqueous chlorine (200 ppm) wash treatment. Tumbling the inoculated sprouts during the chlorine dioxide gas application for 15, 30, and 60 min reduced Salmonella populations by 3.0, 4.0, and 5.5 log CFU/g, respectively, as compared with 3.0, 3.0, and 4.0 log CFU/g reductions obtained without tumbling, respectively. A 2.0 log CFU/g reduction in Salmonella was achieved with an aqueous chlorine wash. The difference in microbial reduction between chlorine dioxide gas versus aqueous chlorine wash points to the important role of surface topography, pore structure, bacterial attachment, and/or biofilm formation on sprouts. These data suggested that chlorine dioxide gas was capable of penetrating and inactivating cells that are attached to inaccessible sites and/or are within biofilms on the sprout surface as compared with an aqueous chlorine wash. Consequently, scanning electron microscopy imaging indicated that chlorine dioxide gas treatment was capable of penetrating and inactivating cells attached to inaccessible sites and within biofilms on the sprout surfaces.
authors.affiliation: Department of Food Science, Rutgers, the State University of New Jersey, New Brunswick, New Jersey 08901, USA.
authors.forename: Vara
authors.initials: V
authors.lastname: Prodduk
authors.affiliation: Food Safety and Intervention Technologies Research Unit, U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, Pennsylvania 19038, USA. bassam.annous@ars.usda.gov.
authors.forename: Bassam A
authors.initials: BA
authors.lastname: Annous
authors.affiliation: Dairy and Functional Foods Research Unit, U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, 600 East Mermaid Lane, Wyndmoor, Pennsylvania 19038, USA.
authors.forename: Linshu
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Food Science, Rutgers, the State University of New Jersey, New Brunswick, New Jersey 08901, USA.
authors.forename: Kit L
authors.initials: KL
authors.lastname: Yam
mesh_terms: D017606:Chlorine Compounds / Q000494:pharmacology*; D015169:Colony Count, Microbial; D004202:Disinfectants / Q000494:pharmacology*; D007887:Fabaceae / Q000382:microbiology*; D005511:Food Handling / Q000295:instrumentation / Q000379:methods*; D005740:Gases / Q000494:pharmacology; D010087:Oxides / Q000494:pharmacology*; D012475:Salmonella / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification
chemical_list: D017606:Chlorine Compounds; D004202:Disinfectants; D005740:Gases; D010087:Oxides; C025109:chlorine dioxide