Purpose: Hot water and household chemicals available to consumers were tested to determine their efficacy for the reduction of S. Typhimurium and L. monocytogenes inoculated on cantaloupe surfaces.
Methods: The efficacy of hot water (82°C) and household chemicals (bleach (0.25% and 0.02% chlorine), vinegar (1% and 0.1% acetic acid), iodine (0.1%), salt (3%) and hydrogen peroxide (1% and 0.1%)) were tested for the reduction of S. Typhimurium and L. monocytogenes inoculated on the cantaloupe surface either by soaking in the solution for 5 or 10 minutes, or by first scrubbing the cantaloupe surface under running water for 1 minute prior to soaking in the solution. Bacteria were enumerated from the treated and control samples to calculate the average log reduction for each treatment. Cryo-scanning electron microscopy was performed to demonstrate that biofilms were present before treatment.
Results: Overall, scrubbing the cantaloupe surface prior to exposure to the sanitizer had a greater log reduction compared to the sanitizer alone. Hot water exposure for 5 minutes with scrubbing was the most effective at reducing S. Typhimurium on the cantaloupe surface (3.8 log reduction). For L. monocytogenes, the hot water treatment for 5 minutes both with and without scrubbing had the highest log reduction (2.5 and 2.2, respectively).
Significance: These results demonstrate consumers can use household sanitizers to reduce pathogenic bacteria on cantaloupe surfaces if they are present. However, the results also indicate it is difficult to effectively remove biofilms once they are present and emphasizes the importance of on-farm prevention to inhibit the formation of biofilms by human pathogens on cantaloupe.