HEAT RESISTANCE OF NONPROTEOLYTIC Clostridium botulinum TYPE F IN PHOSPHATE BUFFER AND CRABMEAT

The heat resistance of nonproteolytic C. botulinum type F in 0.067M phosphate buffer and crabmeat was studied by the thermal death time (TDT) tube method. Replicate experiments at the same temperature (from 160–185°F) were combined for TDT curves and calculation of decimal reduction times (D). D values in buffer ranged from 42.41 min for strain 202 at 160°F to 0.25 min for strain 190 at 180°F. similar to those of type E. Slopes of TDT curves were steeper for type F in phosphate buffer (z = 11.25, 10.4 and 14.75°F) than those reported for type E. Crabmeat protected spores of strain 202, with Food‐phosphate factors ranging from approximately 2 to 4.