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<ol> <LI> Standardize methods for recovering pathogenic and spoilage microorganisms from intact and fresh-cut produce including tree nuts. <LI>Evaluate and control unintentional and intentional microbial contamination of intact and fresh-cut produce including tree nuts.
Non-Technical Summary: Fresh-cut fruits and vegetables present unique challenges because they support greater growth and survival of spoilage and pathogenic microorganisms than do their intact counterparts. Tree nuts support long-term survival of these organisms. This research will assess novel approaches to ensure the highest safety of these products. Methods developed in this lab and in collaboration with others are being used to evaluate interventions designed to remove or reduce foodborne pathogens from the surface of produce and tree nuts. Results are being used in publications directed to consumers and the food industry for the safe handling of fresh and fresh-cut fruits and vegetables and tree nuts. <P> Approach: The overall objective of this project will be to develop basic protocols for inoculation and recovery that could be modified according to various groups of fruits, vegetables, and tree nuts, but used in a standard way to test for the presence and/or populations of foodborne pathogens (Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes) and for the effectiveness of physical methods and chemical sanitizers in removing or killing these microorganisms. Adoption of the inoculation and recovery methods would facilitate comparison of the relative effectiveness of sanitizers and physical treatments for raw vegetables, fruits, and tree nuts regardless of the laboratory conducting the test. The basic protocol could also be used in challenge studies to determine survival and growth characteristics of pathogens on raw produce and tree nuts subjected to various processing and storage conditions. The goals of the research to be performed under this objective are: 1. To develop a standard method(s) for inoculating the surface of fresh and fresh-cut vegetables and fruits, and tree nuts with bacteria capable of causing foodborne illness. 2. To determine the effects of time between inoculation and retrieval on viability and recoverability of foodborne pathogens. 3. To develop a standard method(s) for evaluating the effectiveness of chemical sanitizers and physical treatments such as heat to remove or kill foodborne pathogenic bacteria on the surface of fresh and fresh-cut vegetables and fruits, and tree nuts.