FIGURE 1.

Effect of pressure on survival and post-pressure growth of L. monocytogenes and RTE meat microbiota on ham treated with rosemary extract or an equivalent volume of 0.5% ethanol as solvent control. Shown are cell counts of ham inoculated with a 5-strain cocktail of L. monocytogenes (A) or RTE meat microbiota (B) after treatment at 500 MPa for 1 or 3 min without (white) or with (gray) rosemary extract at ∼325 μg/cm². Cell counts of L. monocytogenes and other strains were monitored immediately after pressure treatment (solid columns) and after storage for 4 weeks at 4°C (hatched columns). Surviving cells were enumerated by surface plating on non-selective TS (L. monocytogenes) or APT agar (RTE meat microbiota). Data are shown as means ± standard deviations of triplicate independent experiments. Treatment means (solid columns) within each panel with different letters are significantly different (P < 0.05). The interception point of abscissa and ordinate represents the highest detection limit.