Combined use of high pressure and salt or sodium nitrite to control the growth of endogenous microflora in raw pork meat

The interaction of high pressure (up to 500 MPa at 20 °C for 6 min) with sodium chloride (0%–3%) or sodium nitrite (0 mg/kg–100 mg/kg) on the outgrowth of four endogenous flora of pork meat was investigated during storage after a cold-chain break. First, the effect of high pressure was investigated. Next, high-pressure treatments at 350 MPa were combined with the addition of salt or sodium nitrite. Interesting results were observed for the lactic acid bacteria of the salted samples. Whereas salt or 350 MPa processing alone was not sufficient to delay the growth of these bacteria until the end of storage, the combination treatment resulted in low microbial counts (below 2 log CFU/g) at the end of storage. The results of this study suggest the existence of a synergy between salt and high pressure that could result from pressure sensitization of bacterial cells.Industrial RelevanceMeat products must contain enough hurdles to inhibit the growth of pathogenic or spoilage microorganisms. The existence of synergy between high pressure and salt or nitrite is promising for the manufacture of meat products. In fact, the use of high-pressure processing could be an approach to limit the addition of salt and nitrite while ensuring extended shelf life, as consumers demand simpler and healthier formulations.

► Interaction between high-pressure and salt or nitrite is evaluated on pork microflora.
► High pressure and salt were particularly efficient at delaying lactic acid bacteria.
► Synergy between the two hurdles was observed from 1.5% salt at 350 MPa.
► Pressure-induced stress is thought to sensitize cells to their environment.