The Disinfection Dilemma: A Critical Review of Disinfection Byproduct Formation, Occurrence, and Toxicological Implications in Ready-to-Eat Fruits and Vegetables

Abstract

The global consumption of ready-to-eat (RTE) produce continues to rise, along with an invisible exposure of chemical residues resulting from postharvest disinfection. This review addresses the disinfection dilemma: the conflicting requirement for pathogen inactivation and the minimization of disinfection byproducts (DBPs). We present a comprehensive overview of the occurrence of trihalomethanes (THMs), haloacetic acids (HAAs), and emerging DBPs across various types of produce and find that most grocery store samples contained measurable amounts of at least one DBP. Leafy greens (e.g., lettuce) contained the highest THM concentrations, driven by their large surface area and tissue exudates. In the reviewed studies, the average DBP concentrations in store-bought produce were 42 μg/kg for THMs and 40 μg/kg for HAAs. Regulatory limits for THMs and HAAs exist for produce wash water, but not for residues on produce. RTE produce remains safe for consumption under the existing postharvest washing procedures, but there remains an opportunity to optimize disinfection through real-time monitoring of wash water quality. Disinfection protocols should also account for variability in wash-water matrices among produce types to limit the risk of unintended DBP formation in RTE produce. Future research should address gaps in current guidelines regarding THMs and HAAs and better characterize unregulated DBPs that may be of health relevance.