Summary of Awards to Date

Cross-contamination risks in dry environments


Jan. 1, 2022 - Dec. 31, 2023

Amount Awarded



Nitin Nitin, Ph.D.
University of California, Davis


Linda J. Harris, Ph.D.


Cross-contamination of fresh produce is a significant risk factor that can contaminate multiple batches of fresh produce and can result in a food safety outbreak. With extensive research, we have developed understanding of the risk factors that promote cross-contamination of fresh produce during wet handling and processing as well as developed tools and technologies to reduce these risk factors. However, there is a lack of knowledge of the risk factors for cross-contamination of fresh produce in a dry environment as well as technologies and tools to reduce these risks. This proposed research plan is aimed at: (a) addressing key gaps in knowledge for managing cross-contamination risks including identification of surface and surface conditions that promote transfer of microbes from a contaminated surface to fresh produce; (b) developing a quantitative risk model to evaluate cross-contamination risks for diverse food contact surfaces and (c) development and validation of novel sanitation technology using food grade light activated antimicrobials. Thus, this comprehensive research approach addresses gaps in knowledge and develop tools and technologies to reduce food safety risks. In addition, development of a novel sanitation technology will address key gaps in sanitation of dry environments for both organic compliant and conventional fresh produce industries.

Technical Abstract

Cross-contamination during handling and processing of fresh produce is one of the key risk factors that can lead to a major food safety outbreak. Despite significant progress in understanding cross-contamination risk factors during wet handling and processing of fresh produce, there are significant gaps in knowledge regarding cross-contamination risk factors in dry environments. These risks are further enhanced by the lack of comprehensive approaches to improve sanitation and cleaning on food contact surfaces in dry environments. To address these needs, this goals of this research are: (a) quantify transfer coefficients of bacteria from inoculated dry food contact surfaces including various plastics and stainless steel surfaces to model fresh produce (e.g., onions and stone fruits) with and without the presence of organic and soil contaminants; (b) develop quantitative risk model for cross-contamination in dry environments; and (c) deploy novel photo activated food grade antimicrobials for sanitation in dry processing environments and compare its efficacy with conventional physical or chemicals cleaning/sanitization methods for reducing cross-contamination risks. Thus, the proposed research plan aims to develop a comprehensive understanding of cross-contamination risk factors during dry handling and processing of fresh produce and develop novel sanitation approaches to mitigate the risks of cross-contamination in dry environments. Success in this project will aid the fresh produce industry by addressing gaps in knowledge, identification of high relative food safety risk surfaces and conditions and developing novel approaches to address cross-contamination challenges.