The temperatures and P-values obtained during reheating of the
paella samples were highly variable (Table 4). Two of the four
reheated samples obtained a P70 of 2 min throughout the entire
product and could be categorized as ready-to-heat, while the other
two samples did not obtain a P70 of 2 min and can be categorized as
ready-to-reheat. However, the maximal temperatures reached in
the rice during reheating ranged from 68.0 C (P70 ¼ 0.2 min) to
90.3 C (P70 ¼ 83.0 min). This range means that the theoretical
reduction of L. monocytogenes ranged from 0.6D to 249D (based on
2 min at 70 C for a 6D reduction). The variation in P-values explains
why L. monocytogenes was still present (in 25 g) in five out of nine
product samples after reheating and demonstrates the importance of validating the reheating as recommended to the consumer. Given
these results, the paella should be categorized as ready-to-reheat
and the producer should not take the reheating at consumer level
into account when setting criteria for L. monocytogenes.