Surviving S. Poona could not be detected by plating on fresh-cut pieces prepared from cantaloupes treated at 97°C but could be detected after enrichment, evidence that a small number of survivors were transferred during fresh-cut preparation. When the initial level of salmonella on the melons was 1.9 log CFU/cm2, no survivors were detected after this treatment, even with enrichment, but with an initial population of 3.5 log CFU/cm2, the treated samples were negative for salmonella by plating but were positive upon enrichment. Similar reductions in the population of salmonella occurred when treatments were applied to cantaloupes stored at 5°C for 5 days as for 3 days. In experiments with E. coli, the efficacy of hot water treatments at lower temperatures was compared with that at 96°C (Table 10.4). Surviving E. coli could be detected on inoculated cantaloupe by plating following treatment at 76°C; no survivors were detected at 86 or 97°C. These hot water treatments, which approach population reductions of 4 log CFU/cm2, represent a substantial improvement over chlorinated water (1000 ppm) or hydrogen peroxide at ~20°C which yielded reductions of only 2 to 3.0 logs.
Additional information concerning hot water treatment of melons can be found in Chapter 21.
Was this article helpful?