Salmonella Sensitivity in a Sorbate/Modified Atmosphere Combination System

The response of Salmonella enteriditis was examined on exposure to a combination treatment of potassium sorbate and modified atmosphere at 10 C. Atmospheres employed were 100, 60 and 20% CO_2; vacuum and an air control. The organisms were exposed to these atmospheres on tryptic soy agar containing 0.0, 0.5, 1.5 or 2.5% potassium sorbate at pH 6.5, 6.0 or 5.5. In the absence of sorbate, only the 100% CO₂ atmosphere inhibited growth; the vacuum and 20 and 60% CO₂ atmospheres were in fact stimulatory. In combination with sorbate, all atmospheres were inhibitory. The combination treatment was increasingly effective with decreasing pH and increasing CO₂ and sorbate concentrations.