Can high-pressure processing be used to manufacture safe hams with reduced levels of preservatives?

• Buffered vinegar or sodium diacetate reduction in hams compromises their safety • HPP and chilled storage ensures safety of hams with reduced levels of preservative • HPP can assist processors develop foods that are both healthy and safe Growing consumer demand for products containing fewer or reduced levels of preservatives have led meat processors to look for strategies to improve food safety while minimizing the use of synthetic preservatives. This study evaluated the effect of high pressure processing (0, 400, 600 MPa for 3 mins) on safety of cooked ham formulated with different levels of buffered vinegar (BV, 1.1, 2.2% w/w), or sodium diacetate (SD, 0.65, 1.3% w/w), surface inoculated (6 log CFU/g) with Salmonella spp or Listeria monocytogenes cocktails, and stored at 4 or 7°C for up to 28 days. Regardless of formulation, storage at 4 or 7°C did not support growth of Salmonella spp. In contrast, L. monocytogenes counts in hams formulated without preservatives or lower preservative levels increased over the storage period, while the bacteriostatic effect of BV and SD was evident at 2.2 and 1.3%, respectively. 600 MPa resulted in reduction of both Salmonella spp. and L. monocytogenes in all formulations to levels below detection limit and remained at that level during storage. 400 MPa resulted in a 0.7- to 1-log CFU/g reduction in L. monocytogenes counts and remained unchanged over 28 days storage at 4°C, while at 7°C, L. monocytogenes counts in formulations without preservative increased by ∼1.75-log CFU/g, while counts in formulations with preservatives showed a concentration dependent inhibition ( P > 0.05). These results suggest that HPP at 600 MPa along with controlled low temperature storage could be effectively used to enhance safety of cooked hams formulated with lower levels of preservatives.