FACTORS IN SURVIVAL OF CLOSTRIDIUM BOTULINUM TYPE E SPORES THROUGH THE FISH SMOKING PROCESS

Abstract

Fish, experimentally inoculated with 1 ×106 Clostridium botulinum type E spores, were given heat treatments equivalent to those used in commercial smoking (180 F for 30 min following come-up time of 2.5 – 3 hr). The percentages of such fish containing viable type E spores were significantly lower among fish heated in an environment of high moisture than among those heated in atmospheres of low moisture. Type E spores heated in raw fish mince were more heat resistant than those heated in mince that was previously autoclaved. A similar difference was observed for spores in raw and cooked egg white, another substrate which coagulates rapidly at the temperature of thermal death time studies (82.5 C). Spores in the drippings of fish hung for heating survived heat processing and could be a source of cross contamination.