In recent years, several foodborne illness outbreaks have been associated with the consumption of cantaloupe. Cantaloupes can be contaminated with pathogens anywhere from the field to the packing line. In the United States, cantaloupes are handled and packed differently in each state. Georgia-grown cantaloupes are brought to sheds, washed, and packed, whereas California-grown cantaloupes are field packed. In this study, the microbiological status of cantaloupes produced by four Georgia growers that use various washing and packing practices was assessed to determine the influence of these different practices. The facilities were visited four times during the harvest season. Aerobic bacteria, Escherichia coli, and coliforms on these Georgia-grown cantaloupes were enumerated in transport trailers, after washing, and after packing. Samples also were analyzed for the presence of Salmonella and E. coli O157:H7. In sheds 1 and 4, a chlorinated dump tank was used to wash melons. In sheds 2 and 3, heated water with chlorine was used in the dump tanks. Although there was a significant reduction (P < 0.05) in the populations of the aerobic bacteria and E. coli between the transport trailer and the dump tank for sheds 1 and 4, the reduction was less than 0.5 log CFU/cm2. The temperatures of the water in the dump tanks at sheds 2 and 3 were not high enough to effectively reduce the microbial populations evaluated. Populations on the melons increased slightly (< 0.5 log CFU/cm2) after the melons were removed from the dump tank, suggesting possible contamination after washing.

Capacitance monitoring is commonly used as an efficient means to gen-

Outbreaks of Clostridium perfringens have been associated with dishes containing refried beans from food service establishments. However, growth of C. perfringens in refried beans has not been investigated, and predictive models have not been validated in this food matrix. We investigated the growth of C. perfringens during the cooling of refried beans. Refried beans (pinto and black, with and without salt added) were inoculated with 3 log CFU/g C. perfringens spores and incubated isothermally at 12, 23, 30, 35, 40, 45, and 50°C. The levels of C. perfringens were monitored 3, 5, 8, and 10 h after inoculation, and then fitted to the Baranyi primary model and the Rosso secondary model prior to solving the Baranyi differential equation. The final model was validated by dynamic cooling experiments carried out in stockpots, thus mimicking the worst possible food service conditions. All refried beans samples supported the growth of C. perfringens, and all models fit the data with pseudo-R(2) values of 0.95 or greater and mean square errors of 0.3 or lower. The estimated maximum specific growth rates were generally higher in pinto beans, with or without salt added (2.64 and 1.95 h(-1), respectively), when compared with black beans, with or without salt added (1.78 and 1.61 h(-1), respectively). After 10 h of incubation, maximum populations of C. perfringens were significantly higher in samples with no salt added (7.9 log CFU/g for both pinto and black beans) than in samples with salt added (7.3 and 7.2 log CFU/g for pinto and black beans, respectively). The dynamic model predicted the growth of C. perfringens during cooling, with an average root mean squared error of 0.44. The use of large stockpots to cool refried beans led to an observed 1.2-log increase (1.5-log increase predicted by model) in levels of C. perfringens during cooling. The use of shallower pans for cooling is recommended, because they cool faster, therefore limiting the growth of C. perfringens.