Effect of Storage Temperatures and Cooking Times on Viability of Listeria monocytogenes and Escherichia coliO157: H7 Inoculated in/on Goetta

Abstract

The viability of a five-strain cocktail of Listeria monocytogenes or Escherichia coliO157:H7 was separately evaluated in/on goetta, a sausage-like meat product, both during extended refrigerated storage and following cooking. At 4C, L.monocytogenes numbers increased from ca. 1.4 to 8.4log cfu/g over 90 days, whereas E.coliO157:H7 numbers remained relatively unchanged. At 12C, L.monocytogenes and E.coliO157:H7 numbers increased from ca. 1.4 to 9.0log cfu/g over 28 days. After cooking for 2 to 6min per side at an external temperature of 176.7C, reductions of 0.7 to 6.6log cfu/g were observed for L.monocytogenes and E.coliO157:H7. Although goetta supported the growth/survival of L.monocytogenes and E.coliO157:H7 during refrigerated storage, a ≥5-log reduction of both pathogens was achieved by cooking the product for at least 5min per side at the manufacturer's recommended internal temperature of 73.8C. © 2013 Wiley Periodicals, Inc.