Title: Thermal and non-thermal decontamination treatments for inactivation of Salmonella on inoculated cantaloupe surfaces Author
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: October 14, 2008
Publication Date: October 16, 2008
Citation: Annous, B.A. 2008. Thermal and non-thermal decontamination treatments for inactivation of Salmonella on inoculated cantaloupe surfaces. [abstract]. The Pennsylvania State University. p. 1. Technical Abstract: Cantaloupes have been implicated in six outbreaks of salmonellosis in the U.S. since 1990. Commercial washing processes for cantaloupes are limited in their ability to inactivate and/or remove this human pathogen, due to biofilm formation and inaccessibility of microbial attachment sites to washing systems. The objective was to develop a surface decontamination treatment capable of reaching and inactivating Salmonella within biofilms or attached to inaccessible sites on artificially contaminated cantaloupe surfaces. Whole cantaloupes, surface inoculated with Salmonella Poona RM 2350 to an approximate final concentration of 5-6 log CFU/cm2, were stored at 4C for 24 h prior to treatment. Inoculated cantaloupes were submerged in hot water at 76C for 3 min or fumigated with 1.6 mg/l chlorine dioxide gas (ClO2) for up to 6 h in a closed chamber that was developed at ERRC. Following treatment, residual populations of S. Poona on whole cantaloupe rinds were enumerated using XLT-4 selective agar medium. There was in excess of 5 log CFU/cm2 reduction in S. Poona populations following hot water or ClO2 treatments. Both treatments extended the shelf life of the cantaloupes at 4C by reducing the population of spoilage microorganisms on the rind surface, and had no adverse effects on the quality of the melon. These studies demonstrated that both treatments were highly effective in inactivating S. Poona attached to inaccessible sites on the cantaloupe rind.