Viability of Salmonella, Escherichia coli o157:h7, and Listeria monocytogenes in dairy and non-dairy yellow fat spreads and toppings

Abstract

Outbreaks of Salmonella, Escherichia coli O157:H7, and Listeria monocytogenes infections associated with dairy products have been documented. Seven dairy and nondairy yellow fat spreads and toppings were inoculated with Salmonella, Escherichia coli O157:H7, or Listeria monocytogenes and stored at 4.4, 10, or 21°C for up to 94 days to determine survival and growth characteristics. Salmonella and E. coli O157:H7 did not grow in any of the test products; however, L. monocytogenes grew in a food service butter and margarine blend stored at 10 and 21°C. The fate of pathogens inoculated onto the surface of six yellow fat products subjected to temperature abuse and high relative humidity followed by storage at 4.4 or 21°C for up to 21 days was also observed. Pathogens grew in a salted, sweet cream whipped butter held at 21°C but not in the unsalted variety or margarine products.