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In an effort to reduce the initial levels of nitrite used to cure bacon and still supply the botulinal inhibition expected in cured meats, bacon was produced at nitrite levels of 0 and 40 ppm NaNO2 with and without 0.13 and 0.26% potassium sorbate. This bacon was inoculated with 1100 spores per g of a mixture of five Type A and five Type B strains of Clostridium botulinum. The time for occurrence of the first swollen package and number of toxic swells were recorded over 110 days of incubation at 27 C. The above variables were compared to bacon containing 80 and 120 ppm NaNO2 as well as a commercial sample. Presence of potassium sorbate in the cure significantly reduced the number of toxic swollen packages occurring during incubation and lengthened the time before a toxic swollen package was observed. The presence or absence of 40 ppm NaNO2 appeared to have no significant effect on the sorbate inhibition of C. botulinum in bacon in this study. Microbial growth of uninoculated samples was also retarded by addition of potassium sorbate to the brine. Flavor panel evaluations indicated that potassium sorbate decreased preference slightly using experienced judges. Also, reduced occurrence of nitrosopyrrolidine with reduced nitrite was observed.

The effect of antioxidants, reducing agents, and a chelating agent were tested in perishable canned cured meat. Isoascorbate, ascorbate, and cysteine enhance the antibotulinal effect of nitrite in perishable canned cured meat. It was determined that this effect was not due to the antioxidant or reducing properties which these compounds possess. The data indicate that they enhance the effect of nitrite by sequestering a metal ion(s) in the meat. It is suggested that nitrite (nitric oxide) reacts with a cation dependent material within the germinated botulinal cell and blocks a metabolic step which is essential for outgrowth. Enhancement of nitrite by isoascorbate, and similar compounds, may be due to preventing repair of damaged material or formation of new cation dependent material.

A series of seven tests was conducted to establish a base line for the inhibition of C. borulinum by nitrite in a perishable canned meat product. The product was subjected to abusive storage at 27°C. The degree of variation in swell times and rates among the tests was determined. Predicted average times to first swell were 6.7, 29.8, 82.6 and 94.3 days when 0, 50, 100 and 156 rig/g of sodium nitrite was added to the meat. The primary effect of nitrite appears to have been in determining the length of the lag phase. Once swelling commenced, the rate at which the cans swelled was not significantly different at 50, 100, and 156 rig/g of sodium nitrite. This information will be used to evaluate additives for controlling botulinal growth and toxin production under the conditions described.

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