The effects of HHP treatment on Listeria monocytogenes inoculated in dry-cured meat products

Because of its relative advantages versus other food processing methods, high pressure processing is increasingly used in products such as sliced cured meats, where a high microbial contamination could appear during the slicing process. This method involves minimal changes in the flavour and nutritional qualities of the final product and assures the protection from microbial spoilage extending the shelf life. This study was aimed on the evaluation of microbiological characteristics at vacuum-packed slices of "cecina" (a Spanish dry-cured meat product) and "salchichon" (a fermented dry sausage) during subsequent extended chilled storage. The dry-cured meat products were inoculated with Listeria monocytogenes cultures to obtain counts that reached 10(4) cfu/g in the products. Meat products were vacuum-packed prior to high hydrostatic pressure processing at 500 MPa for 5 min and stored at 6 degrees C for up to 210 days. For these products, high pressure processing was not as effective as for products with higher aw and the inactivation of L. monocytogenes reached 2 log in "cecina" samples and 1 log in the "salchichon". The low HPP effectiveness obtained was probably due to the low aw of these meat products, which protected cells against pressure.