Sanitizer efficacy in preventing cross-contamination during retail preparation of whole and fresh-cut cantaloupe

The objective of this study was to evaluate the efficacy of tap water (TW), commercial electrolyzed water (EW), and a commercial acid-based sanitizer (AS) in preventing cross-contamination of cantaloupe during processing in retail settings. A whole cantaloupe was dip-inoculated with a cocktail of Salmonella or L. monocytogenes to achieve approximately 5 log CFU/cm2. One inoculated and two non-inoculated whole cantaloupes were treated in 76 L of TW, EW (free chlorine: 50–60 ppm), or AS (pH 2.8, combination of lactic acid and phosphoric acid) for 5 min. Subsequently, fresh-cut cantaloupe flesh from the inoculated and non-inoculated cantaloupes were soaked together in 76 L of TW, EW, or AS for 90 s. EW treatment resulted in an approximately 1.5 log reduction in both Salmonella and L. monocytogenes on the rind of whole cantaloupe, which was significantly greater than with the TW treatment (0.5 log reduction) (P < 0.05). Cross-contamination of non-inoculated whole cantaloupes occurred when washed with inoculated whole cantaloupe in TW (four of four cantaloupes positive for Salmonella and L. monocytogenes) or AS (four of four cantaloupes positive for Salmonella and two of four positive for L. monocytogenes). Cross-contamination did not occur when whole cantaloupes were washed in EW. Additional washing of mixed fresh-cut cantaloupe flesh from the inoculated and non-inoculated cantaloupes prepared after washing of whole cantaloupes demonstrated that the EW treatment reduced the likelihood of cross-contamination compared with TW and AS. No viable Salmonella or L. monocytogenes were detected from 100 mL sample of EW processing water, but were detected in TW and AS (L. monocytogenes only). The addition of a sanitizing agent to water used for the processing of whole and fresh-cut cantaloupe in a retail setting is recommended to prevent cross-contamination and reduce microbial load.