Sliced ready-to-eat traditional meat products presented in individual packaging with more convenience to the consumer is the way that food industry tries to adapt to the new consumer tendencies.
The current work assessed the survival of Listeria monocytogenes in a contaminated sliced vacuum packed chouriço with different sugar concentrations, two salt levels, and presence/absence of Lactobacillus sakei as starter culture along the storage period at two temperatures (8 °C and 22 °C). Neither the inoculation with L. sakei, nor the addition of carbohydrates influenced the survival of the pathogen. Higher amount of salt resulted in a significant reduction of L. monocytogenes, and storage at the higher temperature displayed a safer product. After 7 days, L. monocytogenes was not detected in any samples. The study of the association of the factors contributing for L. monocytogenes survival by logistic regression showed that increasing the level of salt addition from 1.5% to 3% reduces the odds of survival of L. monocytogenes to about one fifth (0.174). Worthy of attention is the significant reduction in the odds (OR=0.028) of finding viable L. monocytogenes when the samples are stored at room temperature (22 °C), when compared to low temperature (8 °C).
The general and indiscriminate use of refrigeration for meat products might increase the risk of presence of L. monocytogenes. The competitive advantage that L. monocytogenes has at low temperatures, as the potential inhibition of LAB activity, is probably the reason of the observed behaviour. The amount of salt was an important hurdle to control L. monocytogenes growth, so, manufacturing meat products with lower salt contents to meet the demands of healthy products might represent a risk for safety, since high levels of salt together with low aw are the keys for their conservation.