Potential growth and control of Salmonella in Hispanic type soft cheese

This study evaluated the growth and control of Salmonella serotypes in a soft Hispanic type cheese (Queso Fresco). Cheese was made in the laboratory using a commercial procedure and after inoculation it was stored under vacuum at temperatures ranging from 6 to 30 degrees C. The minimum temperature that allowed growth of Salmonella was 8 degrees C. Accumulated data from the growth studies were used for the development of models relating the square root of 1/LT (LT = lag time) and specific growth rate to temperature. The effect of selected antimicrobials (potassium sorbate, sodium benzoate and sodium lactate) on the growth and survival of Salmonella in milk and in cheese at various storage temperatures was also examined. Addition of sodium benzoate (0.3%) to cheese (pH 6.6) or addition of potassium sorbate (0.3%) to cheese (pH 6.0) made from milk, which was acidified to pH 5.9 with propionic acid, had a significant impact on delaying or preventing growth of the pathogen.