This project aims to improve the safety and sustainability of postharvest washing of leafy greens such as romaine lettuce and spinach by reducing water use, lowering the risk of cross-contamination,…

The Department of Agriculture National Institute of Food and Agriculture awarded the University of Delaware $728,000 on February 1, 2026, under the Agriculture and Food Research Initiative (AFRI, CFDA 10.310) to improve the safety and sustainability of postharvest washing of leafy greens including romaine lettuce and spinach.

The award funds development and pilot-scale testing of two complementary technologies designed to reduce water consumption, lower cross-contamination risk, and minimize chemical sanitizer reliance. The project evaluates a spray-based in-flight washing system as an alternative to traditional water flumes and develops environmentally friendly sanitizers combining plasma-activated water and nanobubbles to remove and inactivate harmful microorganisms. Testing will assess whether these technologies remain effective, affordable, and preserve the quality, appearance, and shelf life of leafy greens, with results intended to support practical adoption by the U.S. produce industry.

Work is performed in Newark, Delaware. The period of performance runs from February 1, 2026, through January 31, 2030. The award is structured as a Project Grant.

A sub-award to Dr. Luo supports experiment design, data interpretation, and collaboration with Co-PI Dr. Bin Zhou at USDA and PI Dr. Juzhong Tan at the University of Delaware on food safety improvements using integrated approaches combining the in-flight washer, plasma water, and nanobubbles. Dr. Luo is responsible for manuscript preparation and dissemination of findings through peer-reviewed publications, presentations, and direct stakeholder outreach with the produce industry to promote technology transfer.

This project aims to improve the safety and sustainability of postharvest washing of leafy greens such as romaine lettuce and spinach by reducing water use, lowering the risk of cross-contamination, and minimizing reliance on chemical sanitizers. The research will evaluate a spray-based in-flight washing system as an alternative to traditional water flumes and will develop environmentally friendly sanitizers that combine plasma-activated water and nanobubbles to more effectively remove and inactivate harmful microorganisms. The project will test these technologies at a pilot scale to ensure they are effective, affordable, and do not negatively affect the quality, appearance, or shelf life of leafy greens. By providing science-based, scalable solutions, this work supports safer fresh produce, reduced environmental impact, and practical adoption by the U.S. Produce industry.