Sequential antimicrobial treatments enhance cantaloupe and watermelon microbial quality in packinghouse operations

In recent years, outbreaks of foodborne illnesses associated with enteric pathogens in cantaloupes and watermelons have prompted the investigation of treatments that enhance produce safety without compromising its quality. The conditions used in this study simulated a packinghouse conveyor system with brief exposure of the melons to the sanitizers. This study evaluates the efficacy of sequential application of antimicrobial solutions on the microbial quality and shelf-life of cantaloupes and watermelons, simulating commercial packinghouse sprayer systems. Chlorine dioxide (ClO 2 ; 5 mg/L), peracetic acid (PAA; 80 mg/L), and free available chlorine (FAC; 150 mg/L), applied both individually or in combination, were tested via three 5-s immersions, mimicking sequential sprayer exposures, to reduce Escherichia coli O157:H7, Listeria monocytogenes , and Salmonella Typhimurium counts. The ClO 2 and PAA combination (CCP) achieved the highest reduction of foodborne pathogens, with up to 2.17 log CFU/g on cantaloupe rinds and 3.52 log CFU/g on watermelon rinds. Water treatments alone were largely ineffective, underscoring the need to incorporate antimicrobial solutions during the washing of cantaloupes and watermelons. Sensory assessments on whole melons showed no adverse impact on consumer willingness to purchase compared to controls. Refrigeration (4 °C) extended the shelf life fourfold compared to room temperature (22 °C), emphasizing the role of cold storage. These findings suggest that integrating inline sprayer-based antimicrobial solutions with refrigeration enhances microbial safety and shelf life, offering growers a practical strategy for ensuring the safety of fresh produce. • Sequential application of sanitizers reduces pathogens on cantaloupe and watermelon rinds. • Combining ClO₂ and PAA effectively achieves reductions of up to 3.52 log CFU/g. • Treatments preserved quality with no adverse effect on consumer perception. • Water treatments alone were largely ineffective against pathogens.