Pm. Periago et al., APPARENT THERMAL-RESISTANCE OF BACILLUS-STEAROTHERMOPHILUS SPORES RECOVERED UNDER ANAEROBIC CONDITIONS, ZEITSCHRIFT FUR LEBENSMITTEL-UNTERSUCHUNG UND-FORSCHUNG A-FOOD RESEARCH AND TECHNOLOGY, 206(1), 1998, pp. 63-67
The effect of recovering Bacillus stearothermophilus spores under anae
robic conditions on their apparent thermal resistance was studied. Spo
res were suspended in bidistilled water as a reference medium, heated
at 115, 117, 119, 121, 123 and 125 degrees C and recovered under aerob
ic and anaerobic conditions. D values (decimal reduction time) obtaine
d following recovery under anaerobic conditions were lower than those
obtained under aerobic conditions. Reductions of between 31 and 48% we
re found for all the temperatures studied. When spores were suspended
in mushroom extract and recovered under anaerobic conditions the appar
ent heat resistance was much lower than that obtained under aerobic co
nditions (D-121 degrees C was 4.3 min and 1.7 min, under aerobic and a
naerobic conditions, respectively). Heating the spores in mushroom ext
ract and recovering the spores under anaerobic conditions produced an
additive effect, decreasing the apparent heat resistance of the B. ste
arothermophilus spores.