Effect of chemical inhibitors on toxin production by clostridium botulinum in canned comminuted cured meat

The purpose of this experiment was to determine the effect of eight antimicrobials on growth and toxin production by Clostridium botulinum in canned, comminuted cured meat. The antimicrobials evaluated were methyl, ethyl, propyl and butyl parabens, sorbic acid, potassium sorbate, sodium dehydroacetate and sodium benzoate.

Chemicals were first evaluated in thioglycollate broth for their ability to inhibit growth of Clostridium sporogenes and C. botulinum 12885A and ATCC 7949. Results showed that methyl, ethyl, propyl and butyl parabens and sorbic acid were very effective in inhibiting growth of C. sporogenes and C. botulinum 12885A and ATCC 7949. Ethyl, propyl and butyl parabens and sorbic acid were also very effective in inhibiting toxin production by C. botulinum 12885A and ATCC 7949.

Since ethyl, propyl and butyl parabens and sorbic acid completely inhibited toxin production, they were individually added to a pork slurry containing salt and sugar, with or without 40 ppm sodium nitrite. Treatments were dispensed into 206x005 thermal death time cans, inoculated with C. botulinum, and processed at 77°C in a water bath to an internal temperature of 63.5°C. The bulk of the canned product (13 cans/treatment) was abused by holding at 27°C and observed over a three month period. However, in canned, comminuted cured pork, ethyl propyl and butyl parabens and sorbic acid inhibited toxin production, by C. botulinum 12335A and ATCC 7949 at 27°C for a maximum of 23 days. Thus, they delayed outgrowth of C. botulinum but did not inhibit it completely.

These experiments have provided an initial evaluation of the effectiveness of eight antimicrobials against growth and toxin production by botulinum 12885A and ATCC 7949. Expanded studies using additional strains of C. botulinum and utilizing other food systems are necessary to fully evaluate the potential of the selected chemicals as preservative agents against C. botulinum in our food supply.