T9-10 Thermal Process for Inactivating Listeria monocytogenes on Surfaces of Whole Fresh Cantaloupes

Wednesday, July 12, 2017: 11:15 AM
Room 15 (Tampa Convention Center)
Bassam Annous , U.S. Department of Agriculture-ARS-ERRC , Wyndmoor , PA
Angela Burke , U.S. Department of Agriculture-ARS , Wyndmoor , PA
Introduction:  Outbreaks of listeriosis by Listeria monocytogenes have been associated with the consumption of cantaloupes. Commercial washing processes for cantaloupes are limited in their ability to inactivate and/or remove this human pathogen.

Purpose:  Our objective was to develop a surface pasteurization process for enhancing microbiological safety of cantaloupes.

Methods:  Whole cantaloupes, surface inoculated with three strains of L. monocytogenes were stored at 4°C for 24 h prior to processing. Cantaloupes were, then, treated at 80°C for 210 s. Fresh-cut samples were prepared from treated and non-treated cantaloupes and stored at 6°C for up to 12 days.

Results:  Hot water treatments (80°C for 210 s) reduced L. monocytogenes populations in excess of 5 log CFU/g rind. Cantaloupes that were treated and stored at 6°C for 12 days retained their firmness qualities and maintained nondetectable levels of L. monocytogenes as compared to the controls. Also, levels of L. monocytogenes on fresh-cut cantaloupes, prepared from treated cantaloupes and stored for 12 days at 6°C, were nondetectable as compared to the controls.

Significance:  These results indicate that the hot water surface pasteurization at 80°C for 210 s will enhance the microbiological safety of fresh and fresh-cut cantaloupes and will extend the shelf life of this commodity. These results provide a framework to packers/producers of fresh and fresh-cut cantaloupes for the potential use of hot water as an intervention treatment for enhancing the microbiological safety and qualities of this commodity.