Effect of netting density on the efficacy of produce washing solutions in reducing foodborne pathogenic bacteria from cantaloupe rinds

Over the past two decades, the increase in cantaloupe consumption has been associated with the incidence of several multistate foodborne outbreaks. Since cantaloupes grow on the ground, direct soil contact represents a potential consumer risk if the rinds become contaminated with foodborne pathogens. Therefore, this study evaluated the impact of netting density on the efficacy of antimicrobial washes, including sodium hypochlorite (FAC; 200 mg/L free available chlorine), peracetic acid (PAA; 80 mg/L), chlorine dioxide (ClO₂; 5 mg/L), and distilled water (control), in reducing foodborne pathogenic bacteria from cantaloupe rind surfaces. The three cantaloupe varieties with different rind characteristics (smooth-, medium-, and heavy-netted cantaloupes) were inoculated with a mixed culture containing pathogenic strains of Salmonella Typhimurium, Listeria monocytogenes, and E. coli O157:H7. Results showed that increased netting density decreased the sanitizers' efficacy in reducing foodborne pathogenic bacteria. Specifically, bacterial reduction was highest in the smooth-rind variety when treated with peracetic acid and sodium hypochlorite. While chlorine dioxide contributed to the reduction of the load of pathogenic bacteria, its efficacy was significantly lower than the obtained by PAA and FAC treatments. These findings indicate that cantaloupe rind netting substantially affects the efficacy of postharvest washing products, suggesting that food safety concerns are directly related to the capacity of the rind netting to harbor and protect pathogenic bacteria from the action of washing solutions.