title: Behavioural pattern of vegetative cells and spores of Bacillus cereus as affected by time-temperature combinations used in processing of Indian traditional foods.
abstract: This study was undertaken to evaluate the behaviour of vegetative cells and spores of four potent native toxigenic food isolates of Bacillus cereus as affected by selected time-temperature combinations used in processing of Indian traditional foods. The vegetative cells of B. cereus when subjected to sublethal heat treatments, individually, in different heating menstra showed a sigmoidal inactivation pattern, with D-values in the range of 3.45 min at 60 °C to 10.6 min at 56 °C in saline. Accordingly, the z-values recorded across the heating menstra ranged from 9.3 °C in culture broth to 24 °C in whole milk. Similarly, the inactivation pattern for spores for the same isolates was curvilinear with D-values ranging from 4.4 min at 95 °C in whole milk to 19.45 min at 85 °C in saline. The z-values for spores ranged from 16.6 °C in saline to 38.4 °C in whole milk. The thermal inactivation pattern observed for vegetative cells and spores indicate that the death rate was not constant during the process of heat treatment.
authors.affiliation: Human Resource Development, Central Food Technological Research Institute (Council of Scientific and Industrial Research), Mysore, 570 020 India.
authors.forename: Shivalingsarj Vijaykumar
authors.initials: SV
authors.lastname: Desai
authors.forename: Mandyam Chakravarathy
authors.initials: MC
authors.lastname: Varadaraj
keywords: Bacillus cereus; D-values; Heating menstra; Spores; Vegetative cells; z values