Premium
THERMAL RESISTANCE OF BACILLUS CEREUS SPORES AS AFFECTED BY ADDITIVES IN THE RECOVERY MEDIUM
Author(s) -
GONZÁLEZ ISAAC,
LÓPEZ MERCEDES,
MAZAS MARGARITA,
GONZÁLEZ JOSEFA,
BERNARDO ANA
Publication year - 1997
Publication title -
journal of food safety
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.427
H-Index - 43
eISSN - 1745-4565
pISSN - 0149-6085
DOI - 10.1111/j.1745-4565.1997.tb00171.x
Subject(s) - spore , bacillus cereus , food science , sodium , chemistry , sodium citrate , starch , strain (injury) , phosphate , d value , microbiology and biotechnology , bacteria , biochemistry , biology , medicine , organic chemistry , genetics , pathology , anatomy
The effects of the addition of starch, glucose, sodium chloride, sodium citrate, monopotassium phosphate and disodium phosphate to the recovery medium on apparent heat resistance of Bacillus cereus spores (ATCC 4342, 7004 and 9818) were investigated. Sodium citrate, monopotassium and disodium phosphate at concentrations of 0.1% were effective inhibitory agents for heat injured B. cereus spores especially for strain 9818, although only monopotassium and disodium phosphate caused a significant reduction (p < 0.05) in D‐values obtained for strain 9818. Sodium chloride also had a marked effect on the recovery of heat injured spores. Concentration as low as 0.5% caused a significant reduction in the recovery rates for strains 9818 and 7004. In all cases, increasing the salt levels from 0.5 to 4% resulted in a progressive decrease in spore recovery. D‐values gradually decreased as the salt content increased, although the concentrations which produced statistically significant differences (p < 0.05) varied among strains. The addition of starch at 0.1% resulted in a significant increase in the counts for strains 9818 and 7004. In contrast, glucose (0.1%), did not significantly modify the counts obtained Neither of these compounds affected decimal reduction times. No statistical significance (p>0.05) differences were detected among z‐values for the spores of the three strains recovered in the presence of different additives assayed. z‐Values ranged from 6.67 to 8.32, with a mean value of 7.56 ± 0.46C .