IMPROVEMENT TO OZONATING WATER FOR POST-HARVEST WASHING THROUGH NANOBUBBLES

Abstract. As consumer demand for fresh produce continues to grow, so do concerns by theFood and Drug Administration (FDA) about foodborne illnesses and foodborne disease outbreaks.Postharvest wash is a critical control point in fresh produce processing for reducing or eliminatingpathogens and other field-acquired contaminants that can result in such outbreaks. Currentmethods of post-harvest washing typically rely on chlorine-based sanitizers, which provide lessthan 100% efficacy in removing pathogens and are generally acknowledged to have negativeenvironmental and worker safety impacts. Due to such concerns, certain European countries havebanned the use of chlorine as a sanitizing technique for fresh produce. One alternative sanitizingagent being adopted with greater frequency is ozone gas. Ozone, in both its gaseous andaqueous phases, is generally recognized as safe by the FDA and has been shown to effectivelyreduce microbial contamination and pesticide residue; however, worker safety and environmentalconcerns still exist when ozone is not properly managed. Additionally, ozone?s poor solubility andthe high cost of ozone generators have contributed to its limited adoption by the agricultureindustry. En Solución is developing a novel method which utilizes unique cavitation nozzles andair to generate nano-sized bubbles of ozone gas at the point of postharvest wash. Unliketraditional macro-sized bubbles from existing technologies, the nanobubbles produced by the EnSolución methodology have the remarkable ability to remain stable in high concentrations formonths at a time. Worker safety is greatly improved as the ozone does not outgas to theenvironment, but rather, reverts back to oxygen while in the solution. This keeps more ozone inaqueous form and out of the worker environment than traditional generation methods, greatlyenhancing system efficiency. The technology developed by En Solución also has implications onpower and water management, as the automated method reduces the amount of water requiredin washing and facilitates the reuse of water. During the Phase I project, En Solución will fullyvalidate and further develop its technology for application in postharvest washing in consultationwith a pilot farm partner and with experts in food safety, nanotechnology, applied science,agricultural workplace, health and safety and sustainable agriculture practices. In Phase II, EnSolución will move forward with field testing of its technology to determine the degree to whichthe technology presents an improvement over existing sanitizers in terms of safety to workers andthe environment, cost, impact on the product, and consumer acceptability.