Abstract
D- and z-values for a mixture of four Listeria monocytogenes strains originating from the roe of different fish species were determined in rainbow trout (Oncorhynchus mykiss) roe. The D60- and D63-values obtained were 1.60 and 0.44 min, respectively, and the z-value
was 5.36°C accordingly. In pilot-scale experiments, rainbow trout roe
(100 g) was vacuum packaged into glass jars and pasteurized both at 62
and 65°C for 10 min. These treatments were enough to destroy 108 CFU/g of L. monocytogenes cells, which was the highest possible Listeria cell count to grow in roe. On the basis of the determined z-value
and calculation of pasteurization values, these experimental
pasteurizations were found to theoretically destroy at least 45 log
units of L. monocytogenes cells in rainbow trout roe. In
addition, these pasteurization treatments did not significantly affect
the sensory quality of the roe. The sensory quality of pasteurized
vacuum-packaged rainbow trout roe stored at 3°C was evaluated as good
after 6 months of storage and not statistically different from the
control that was frozen from the same roe lot as the pasteurized roe
samples. Pasteurization of rainbow trout roe was proven to be an
appropriate method for ensuring product safety with regard to L. monocytogenes
and to stabilizing the sensory and microbial quality of roe. However,
the safety risk caused by spore-forming bacteria still exists in
pasteurized roe. Therefore, it has to be stored below 3°C.
Original language | English |
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Pages (from-to) | 1641 - 1647 |
Number of pages | 7 |
Journal | Journal of Food Protection |
Volume | 68 |
Issue number | 8 |
DOIs | |
Publication status | Published - 2005 |
MoE publication type | A1 Journal article-refereed |