2011 Annual Report 1a.Objectives (from AD-416) 1. Inactivation of pathogens and prevention of cross-contamination through optimization of produce wash system design and operation; 2. Development of innovative washing processes and technologies; and 3. Prevention of pathogen proliferation in supply chain. 1b.Approach (from AD-416) This project takes a system-based and trans-disciplinary approach to address food safety issues of leafy green vegetables. The project involves research in the fields of mechanical engineering, microbiology, post-harvest technology, and food processing. "Speciality Crop Research Initiative." 3.Progress Report Chlorine is widely used as a sanitizer during fresh-cut wash operations. However, the large amount of organic materials in the exudates released by lettuce cutting depletes free chlorine rapidly, resulting in the potential for pathogen survival and cross-contamination. We evaluated various options including a rinse step between cutting and washing on removing organic load without incurring additional water usage. We demonstrated that a rinse after cutting and prior to washing can cost-effectively reduce water quality deterioration and retain sanitizer efficacy on pathogen survival during fresh-cut wash operations. Intensive research has been conducted in the proposed research areas and the progress of this project has been closely monitored by the ADODR via frequent contact with our stakeholder advisory board members, the Co-PIs from University of Illinois, University of California, North Carolinas State University, and University of Arizona, via conference calls and e-mail communications.