Application of enterocins A and B, sakacin K and nisin to extend the safe shelf-life of pressurized ready-to-eat meat products

The efficiency of food preservation systems is determined by the technologies that are combined, the intrinsic properties of the food products and the target microorganisms. In the present study, the bacteriocins nisin, enterocins A and B and sakacin K were applied to cooked and dry cured ham spiked with Listeria monocytogenes, Salmonella enterica and Staphylococcus aureus and submitted to a high pressure treatment of 600 MPa. Before pressurization nisin produced significant reductions to the counts of L. monocytogenes and S. aureus, especially in dry cured ham. After the pressurization, Salmonella and L. monocytogenes were not detected in 25 g of both cooked and dry cured ham and remained at this level during the entire storage (57 days at 4 degrees C + 63 days at 15 degrees C). S. aureus levels, in contrast, only decreased below the detection limit (1 log CFU/g) in the nisin batches. Afterward, when storage was performed at an abusive temperature, the ability of S. aureus to grow was dependant on the bacteriocin applied and the kind of meat product. Thus, at the end of storage, while S. aureus counts were < 1 log CFU/g in all dry cured ham batches, only nisin could inhibit its growth in cooked ham.