EFFECTS OF VARIOUS CONCENTRATIONS OF SODIUM NITRITE AND POTASSIUM SORBATE ON Clostridium botulinum TOXIN PRODUCTION IN COMMERCIALLY PREPARED BACON

Abstract

ABSTRACTThe study consisted of five treatments including formulations with or without sodium nitrite (120 ppm) or potassium sorbate (0.26%) or both nitrite (40, 80 ppm) and sorbate (0.26%). Packages (300 per treatment) of commercially prepared bacon were inoculated with Clostridium botulinum spores from 10 strains (5 type A and 5 type B) and temperature abused at 27°C. Uninoculated packages (100 per treatment) were also abused. The packages were visually checked for gas production during a 60‐day incubation period and tested for botulinal toxin. Spore and vegetative cell counts, aerobic total plate counts, product pH, residual nitrite depletion, and sorbate levels were also monitored. Toxic samples frequently occurred without gas, and many samples showing gas were nontoxic. Added sorbate or added nitrite extended the time to detection of first gas‐containing and first toxic samples. A combination of sorbate (0.26%) with reduced nitrite levels (40, 80 ppm) extended this time further. Nitrite or sorbate used singly in the formulation also decreased the rate of toxin production. None of the uninoculated packages was toxic, while the total number of toxic inoculated packages decreased with nitrite or sorbate in the formulations. Ninety percent of the samples from the control treatment became toxic during the 60‐day incubation period; 58.8% from the treatment with 0.26% sorbate; 22.0% from the treatment with 40 ppm nitrite and 0.26% sorbate; none from the treatment with 80 ppm nitrite and 0.26% sorbate; and 0.4% from the treatment with 120 ppm nitrite. Low nitrite‐sorbate combinations were thus effective in delaying botulinal toxin production in temperature abused bacon.