2011 Annual Report 1a.Objectives (from AD-416) ARS is interested in integrated approaches to improve produce safety while maintaining quality. The Cooperator, University of Maryland, is interested in evaluating the produce surface characteristics and sanitizer efficacy on pathogen reduction. The Cooperator has the expertise and infrastructure to effectively conduct the proposed research activities. 1b.Approach (from AD-416) ARS will acquire the basic knowledge of the factors influencing sanitizer degradation, pathogen attachment and internalization during leafy greens and tomato wash process. The Cooperator will provide the expertise in anti-microbial, surface adsorption, topography, and other characteristics in relation to sanitizer performance on pathogen reduction. 3.Progress Report The agreement was formalized by the recruitment of a visiting scientist to undertake the studies on the effect of tomato packing house operations on dump tank water quality and Salmonella infiltration. We audited the tomato packing house operations and investigated the incidence of Salmonella infiltration as impacted by tomato variety, post-stem removal time, and the temperature differential between tomato pulp and bacteria suspension. We reported that tomato varieties and post-stem removal time significantly affected the frequency and population of Salmonella infiltration. Information generated will help to establish science-based tomato handling standards to prevent pathogen contamination and internalization. The progress of this project has been closely monitored by the ADODR via frequent contact with the PI at the University of Maryland via conference calls, face-to-face meetings, and e-mails.