Acid Enhancement of Clostridium botulinum Inhibition in Ham and Bacon Prepared with Potassium Sorbate and Sorbic Acid

The effectiveness of combinations of sorbic acid and other acids (hydrochloric, phosphoric, acetic, citric, lactic and succinic) on Clostridium botulinum inhibition in comminuted ham and nitrite-free bacon was studied. These acids, when added to ham to give similar pH's, did not significantly inhibit the organism, but when acetic or citric acid was added with sorbic acid, inhibition was greater than with sorbic acid alone. The acids were less effective in inhibiting C. botulinum when added to sorbic acid-containing bacon. A study of the effectiveness of three levels of potassium sorbate (0.10, 0.26 or 0.52%) or sorbic acid (0.08, 0.20 or 0.40%) and two levels of phosphoric acid (0.04 or 0.08%) in comminuted ham showed that the highest levels of sorbate or sorbic acid were sufficient to inhibit toxin production when incubated at 30°C for 180 d. The same degree of C. botulinum inhibition was afforded by 0.26% sorbate with 0.08% H₃PO₄ or by 0.20% sorbic acid with 0.04% H₃PO₄. These differences were probably due to the higher pH obtained with sorbate.