Heat resistance of Clostridium sordellii spores

Abstract

The thermal destruction kinetics of Clostridium sordellii spores was studied in this research. Decimal reduction times (D values) for C. sordellii ATCC 9714 spores ranged between 175.60 min for D(80) (the D value for spore suspensions treated at 80 degrees C) and 11.22 min for D(95). The thermal resistance (Z) and temperature coefficient (Q(10)) values of spores were calculated to be as high as 12.59 degrees C and 6.23, respectively. At 95 degrees C, the relative thermal death rate and relative thermal death time of C. sordellii ATCC 9714 spores were found to be 0.0085/min and 118 min, respectively, indicating that the death rate of spores was 118 times lower at 95 degrees C than at 121.1 degrees C. Heat treatments at up to 85 degrees C for 120 min failed to cause a 100-fold destruction in spore populations of C. sordellii ATCC 9714. By contrast, spore counts were reduced by 2 log(10) cycles within 73 min and 23 min at 90 degrees C and 95 degrees C, respectively. This is the first published report of thermal inactivation of C. sordellii spores; however, further studies are needed to confirm these results in real food samples.