Pk. Benembarek et Hh. Huss, HEAT-RESISTANCE OF LISTERIA-MONOCYTOGENES IN VACUUM-PACKAGED PASTEURIZED FISH FILLETS, International journal of food microbiology, 20(2), 1993, pp. 85-95
The heat resistance of two strains of Listeria monocytogenes in sous-v
ide cooked fillets of cod and salmon was investigated. Fish sticks of
5 g were inoculated, vacuum-packed and heated at different combination
s of time and temperature (58-80 degrees C). Time-temperature combinat
ions allowing survival and time-temperature combinations at which the
bacteria were destroyed, were used to determine D-and z-values. D-valu
es were in the range of what has been published for other food product
s. D-60-values were between 1.95 and 4.48 min depending on the strain
and the fish. Both strains were one-four-times more heat resistant in
salmon than in cod, showing the importance of the heating menstruum. T
his difference may be due to the higher fat content in salmon as compa
red to cod. Z-values were calculated to be 5.65 and 6.4 degrees C, res
pectively, for the two strains. The suitability of methods for heat re
sistance experiments and the survival of L. monocytogenes in sous-vide
cooked fish fillets are discussed.