Adherence of bacteria to cantaloupe rind is favored by surface irregularities such as roughness, crevices, and pits, thus reducing the ability of washing or sanitizer treatments to remove or inactivate attached cells.
In a study published in the August issue of the Journal of Food Protection, researchers compared the surface charge and hydrophobicity of two cantaloupe-related outbreak strains of Salmonella Poona to those of 14 additional Salmonella strains using electrostatic and hydrophobic interaction chromatography. The relative abilities of the 16 strains to attach to cantaloupe surfaces and resist removal by washing with water, chlorine, or hydrogen peroxide for 5 min after a storage period of up to 7 days at 5 to 20 degrees C also were determined.
Whole cantaloupes were inoculated with each pathogen, dried for one hour inside a biosafety cabinet, stored, and then subjected to the washing treatments.
The two cantaloupe-related outbreak Salmonella Poona strains did not significantly differ from the other Salmonella strains tested in negative cell surface charge or hydrophobicity, were not more effective in attaching to whole melon surfaces, and were not more resistant to the various washing treatments when present on rinds.