Production of mortadella: behavior of Listeria monocytogenes during processing and storage conditions

The presence of Listeria monocytogenes in ready-to-eat meat products is cau se of concern to the food industry as well as to health authorities. Studie s were conducted to evaluate the presence of L. monocytogenes in mortadella s acquired at retail stores and to evaluate the fate of two levels of a L. monocytogenes pool spiked in two different formulations of the product, coo ked under commercial conditions and stored at refrigeration (7 degreesC) an d room temperature (25 degreesC). Among the samples collected at different retail stores, 26.7% harboured L. monocytogenes. Regarding to the fate of L . monocytogenes in mortadella, periodically, samples were taken and the sur viving L. monocytogenes cells in the spiked products were counted by the MP N procedure. Populations of <0.35 MPN/g of L. monocytogenes were found in t hese samples. It could be concluded that the heat treatment was effective t o reduce 3-log of L. monocytogenes independent of formulation or storage co nditions. (C) 2000 Elsevier Science Ltd. All rights reserved.