Factors controlling the growth of Clostridium botulinum types A and B in pasteurized, cured meats III. The effect of potassium sorbate

The growth of Clostridium botulinum types A and B spores, at 10¹ or 10³ per container, was studied in a pork slurry system containing nitrite (40 μg/g), sodium chloride (2.5, 3.5, 4.5% w/v) sodium isoascorbate (550 μg/g) at varying pH levels, with or without potassium sorbate (0.26% w/v), without heating and after two heat treatments (80°C for 7 min, and 80°C for 7 min + 70°C for 1 hr) followed by storage at 15, 17.5, 20 or 35°C for up to 6 months. At a given spore inoculum, potassium sorbate significantly decreased toxin production, as did increasing NaCl, decreasing pH or decreasing storage temperature. Heat treatment did not significantly affect spoilage or toxin production overall, but interacted significantly with some factors. The effect of sorbate was greater at 3.5% NaCl than at 2.5%, at pH values below 6.0, and at low storage temperature.