Inhibition of Botulinum Toxin Formation in Bacon by Acid Development

Abstract

Lactobacillus plantarum, as a producer of lactic acid, and sucrose as a fermentable carbohydrate were evaluated for use in lowering the amount of or eliminating sodium nitrite in bacon. This work was limited to effect on antibotulinal properties. Organoleptic effects were not considered. Slices of bacon were inoculated with spores of Clostridium botulinum types A and B with or without simultaneous inoculation with a culture of L. plantarum, vacuum-packaged and incubated at 27 C. Samples were taken after various periods of incubation and assayed for botulinal toxin. We found that (a) sodium nitrite alone, at 120 ppm, did not give bacon extended protection against development of botulinum toxin if a fermentable carbon source (sucrose in these instances) was not present; (b) without added lactic acid bacteria, the effectiveness of 120 ppm of sodium nitrite plus sugar was variable and depended upon growth of naturally contaminating bacteria and (c) lactic acid bacteria with an adequate amount of sucrose gave good protection against development of botulinal toxin. Upon temperature abuse, acid was produced and growth of C. botulinum was inhibited. Because the protective properties against development of botulinal toxin in the sugar-lactic acid bacteria system were not dependent on the presence of nitrite, nitrite can be lowered to the level necessary to make organoleptically acceptable products without sacrificing safety, thus less nitrosamine formation may be achieved.