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Behavior of Vegetative Cells and Spores of B acillus cereus in Two Food Systems
Author(s) -
Desai Shivalingsarj Vijaykumar,
Varadaraj Mandyam Chakravarthy
Publication year - 2013
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/jfs.12052
Subject(s) - cereus , bacillus cereus , spore , food science , biology , population , microbiology and biotechnology , bacteria , genetics , demography , sociology
The survival and growth of vegetative cells and spores of toxigenic B acillus cereus CFR 1534 was investigated in a dehydrated (dry mix) blend of flour (roasted finger millet and Bengal gram) and chocolate milk. In the case of dry mix, there was a marginal initial increase of 2 logs in 2 days of storage at 20 and 30C, respectively. In chocolate milk, there was an increase of 1 log with certain inoculum levels introduced and storage temperatures. The survival pattern of vegetative cells/spores was primarily influenced by the initial numbers and, to a slight extent, by the water activity of food matrices. Although stored samples were negative for toxigenic trait of phosphatidylinositol phospholipase C in polymerase chain reaction, associated lecithinase activity was detected in plate assay. Response surface plots for vegetative cells and spores of B . cereus CFR 1534 did indicate the potential risk associated with post‐processing contamination of B . cereus . Practical Applications The ability of vegetative cells and spores of a toxigenic culture of B acillus cereus to survive and grow in two food matrices was studied. Often, the bacterial species tend to remain in the product and increase in their numbers in a slow paced manner. The product with no visual changes, but harbors viable population of toxigenic B acillus cereus can be of serious public health concern. The understanding of product profile would be of help in assessing the probable risk factors that could be associated with opportunistic foodborne pathogen like B . cereus in the food chain establishment.