Assessment of Sodium Hypochiorite and Acidified Sodium Chlorite as Antimicrobial Agents to Inhibit Growth of Escherichia coli 0157:H7 and Natural Microflora on Shredded Carrots

Acidified sodium chlorite (ASC) is an alternative to chlorine in reducing microbial populations to maintain food quality and safety on fresh-cut produce. However the most effective concentration for microbial reduction on shredded carrots is unknown. In this study the influence of tap water, sodium hypochlorite (SH; 200 mg-L1) and acidified sodium chlorite (ASC; 100,250,500 and 1,000 mg-L') washes on natural microflora, and survival and growth of Escherichia coli 0157:H7 inoculated onto shredded carrots, was determined after treatment and 7 and 14 days of storage. The carrots were stored under passive Ana Allende is affiliated with the Research Group on Quality, Safety and Bioactivity of Plant Foods, CEBAS-CSIC, Murcia, Spain (E-mail: [email protected]). Rolando J. Gonzalez is affiliated with Bix Produce Company, St. Paul, MN 55117 (E-mail: RolandoG @bixproduce.com ). James McEvoy (E-mail: [email protected]) and Yaguang Luo (E-mail: [email protected]), are both affiliated with the Produce Quality and Safety Laboratory, USDA, ARS, Beltsville, MD 20705. Address correspondence to: James McEvoy at the above address. Use of a company name or product by the USDA does not imply approval or recommendation of the product to the exclusion of others that also may be suitable. International Journal of Vegetable Science, Vol. 13(3) 2007 Available online at http://ijvs.haworthpiess.com © 2007 by The Haworth Press. All rights reserved. doi:10.1300/J512v13n03_05 51 52 INTERNATIONAL JOURNAL OF VEGETABLE SCIENCE modified atmosphere at 5°C. While a tap water wash did not reduce growth of E. coli 0157:H7, total plate count or yeast and molds, spoilage and pathogenic microorganisms were reduced by two logs by using SH or ASC at 200 and 100 mg-L1, respectively. ASC at concentrations above 100 mg-Lwas very effective in reducing microbial growth by 6 logs. During storage, total mesophilic growth increased in samples washed with tap water, SH orASC at 100 and 250 mg-L'. However, shredded carrots washed with ASC at 1000 mg-L -1 did not show any microbial growth even after 14 days of storage at 5°C. doi: 10.1 300/J5 12v I 3n03_05 fArticle copies available for a fee from The Haworth Document Delivery Service: 1-800-HA WORTH. E-mail address: Website: © 2007 by The Haworth Press. All rights reserved.]