Publications - Faculty - Recently Submitted Faculty Publications 2008
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Danyluk -Journal of Food Protection
Fate of Escherichia coli O157:H7 and Salmonella spp. on Fresh and Frozen Cut Pineapples
Laura K. Strawn and Michelle D. Danyluk
Abstract.Pineapples have been associated with outbreaks of E. coli and Salmonella. Little is known about the behavior of E. coli O157:H7 and Salmonella on cut pineapple. The objectives of this study were to evaluate the fate of E. coli O157:H7 and Salmonella on fresh and frozen cut pineapples and the influence of acid adaptation on Salmonella survival on fresh cut pineapple at ambient storage (23°C). Cut pineapples were spot inoculated with either a four strain or five strain cocktail of E. coli O157:H7 or Salmonella, respectively. Inoculated samples were air dried, placed in containers and stored at 4, 12, 23 and -20°C. Samples were enumerated following stomaching on nonselective and selective media at days 0, 1, 3, 5, 7, 10, 14, 21 and 28 (4 and 12°C); 0, 1, 3, 5 and 7 (23°C) and 0, 7, 14, 21, 28, 60, 90, 120, 150 and 180 (-20°C). Population levels in log CFU/g of pineapple were calculated. E. coli O157:H7 and Salmonella inoculated onto pineapple did not grow, but survived at levels sufficient to cause foodborne illness for the shelf life of each temperature condition, with improved survival at lower temperatures. E. coli O157:H7 and Salmonella can survive on frozen cut pineapples for at least 180 days. Acid adaptation of Salmonella did not, allow growth or increase survival. Fresh and frozen cut pineapples are potential vectors for E. coli O157:H7 and Salmonella transmission and preventive procedures should be implemented during production and postharvest processing.
