Novel Wash Aid T-128 Enhances the Efficacy of Chlorine against Salmonella on Tomatoes

Abstract

A novel wash aid, T-128, was evaluated for its capacity to enhance the efficacy of chlorine solution for tomato washing against Salmonella enterica in the presence of high organic load. Incremental amount of tomato juice was added to chlorinated wash solutions to simulate free chlorine depletion during tomato washing operations. Cells of S. enterica were either directly inoculated into the wash solutions or onto the tomatoes that are washed in chlorinated solutions with or without T-128. Salmonella cells survived in the wash solution, in the stem-scar areas, and in the internal tissues of tomatoes were enumerated. Application of T-128 significantlyreduced the survival of Salmonella in chlorinated water when free chlorine approached depletion. It also resulted in a significantly higher reduction of S. entericapopulation on stem scars compared to the control. When inoculated and non-inoculated tomatoes were washed together, cross contamination by Salmonella cells to the non-inoculated tomatoes were reduced in the presence of T-128. The application of T-128 also significantly improved the chlorine efficacy against Salmonella internalization when chlorine concentration was near depletion. These results indicated that T-128 has the potential to improve chlorine efficacy against pathogen survival, cross-contamination and internalization in the wash solution when chlorine neared depletion, thus improve the safety margin of the process control.