Aqueous solutions of sodium hypochlorite or hypochlorous acid are typically used to sanitize fresh fruits and vegetables. However, pathogenic organisms occasionally survive aqueous sanitization in sufficient numbers to cause disease outbreaks. Chlorine dioxide (ClO2) gas
generated by a dry chemical sachet was tested against foodborne pathogens on lettuce leaves. Lettuce leaves were inoculated with cocktail of three strains each of Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Typhimurium and treated with ClO2 gas
for 30 min, 1 h, and 3 h in a model gas cabinet at room temperature (22 ± 2°C). After treatment, surviving cells, including injured cells, were enumerated on appropriate selective agar or using the overlay agar method, respectively. Total ClO2 generated by the gas packs was
4.3, 6.7, and 8.7 mg after 30 min, 1 h, and 3 h of treatment, respectively. Inoculated lettuce leaves exposed to ClO2 gas for 30 min experienced a 3.4-log reduction in E. coli, a 4.3-log reduction in Salmonella Typhimurium, and a 5.0-log reduction in L. monocytogenes
when compared with the control. After 1 h, the three pathogens were reduced in number of CFU by 4.4, 5.3, and 5.2 log, respectively. After 3 h, the reductions were 6.9, 5.4, and 5.4 log, respectively. A similar pattern emerged when injured cells were enumerated. The ClO2 gas sachet was
effective at killing pathogens on lettuce without deteriorating visual quality. Therefore, this product can be used during storage and transport of lettuce to improve its microbial safety.
Document Type: Research Article
Department of Food Science and Human Nutrition, Washington State University, Pullman, Washington 99164–6376, USA
Publication date: July 1, 2004
More about this publication?
IAFP members must first sign in on the right to access full text articles of JFP First published in 1937, the Journal of Food Protection®, is a refereed monthly publication. Each issue contains scientific research and authoritative review articles reporting on a variety of topics in food science pertaining to food safety and quality. The Journal is internationally recognized as the leading publication in the field of food microbiology with a readership exceeding 11,000 scientists from 70 countries. The Journal of Food Protection® is indexed in Index Medicus, Current Contents, BIOSIS, PubMed, Medline, and many others.
Print and online subscriptions are available to Members and Institutional subscribers. Online visitors who are not IAFP Members or journal subscribers will be charged on a pay-per-view basis. Information can be obtained by calling +1 800.369.6337; +1 515.276.3344; fax: +1 515.276.8655, E-mail: firstname.lastname@example.org or Web site: www.foodprotection.org