a P90-value of 10 min (z ¼ 7 C), i.e. it will cause the same reduction
in C. botulinum as heating 90 C for 10 min. However, this method
cannot be extrapolated indefinitely. Below a certain temperature
there will be no inactivating effect of temperature on the microorganism.
Since the target-organism during reheating is
L. monocytogenes, the P70was calculated (eq. (1)). However, in some
products the recorded temperature was sufficiently high calculate
the P90-value of these products was calculated using eq. (2). If
a product consisted of multiple components (e.g. meat and vegetables),
the temperature and P-value were determined separately
for each component.