THE STABILITY OF CLOSTRIDIUM BOTULINUM TOXIN TYPE A ON FRESH AND FRESH-CUT PRODUCE by ROBIN GWEN

FRESH-CUT PRODUCE by ROBIN GWEN SALINSKY BROEKER (Under the Direction of Mark Harrison) ABSTRACT Foodborne botulism is a potentially lethal neuroparalytic illness resulting from ingesting C. botulinum neurotoxins. There is little information concerning the stability of preformed toxin on fresh produce. This research determined the stability of toxin type A on whole grape tomatoes, pre-cut lettuce, and pre-sliced cantaloupe. Different combinations of toxin inoculum pH (5.5 or 7.0) and storage temperature (4, 15, or 25C) were analyzed to determine their relationship to the rate of toxin decay. The toxin was measured using the DIG-ELISA method, which screens for the presence of botulinal toxin type A. For tomatoes, the toxin inoculum at pH 5.5 and storage temperature of 25C provided the most stability for the toxin. For lettuce, the toxin inoculum at pH 7.0 and storage temperature of 15C provided the most stability. For cantaloupe, only the temperature of 4C provided stability to the toxin.