FATE OF BACILLUS CEREUS IN CULTURED AND DIRECT ACIDIFIED SKIMMILK AND CHEDDAR CHEESE1
- 1 June 1973
- journal article
- Published by International Association for Food Protection in Journal of Milk and Food Technology
- Vol. 36 (6) , 317-320
- https://doi.org/10.4315/0022-2747-36.6.317
Abstract
Germination, growth, sporulation, and. survival of Bacillus cereus 7 was determined in cultured (Streptococcus lactis C10) and direct acidified (lactic acid) skimmilks. For cultured systems, B. cereus increased initially at approximately the same rate in milks with or without streptococci. However, as the acidity of the milk increased, vegetative B. cereus cells failed to survive but spore counts remained unchanged. B. cereus organisms did not influence acid production or multiplication of the lactic streptococci. In direct acidified skimmilk, spore germination and outgrowth and vegetative cell multiplication decreased as the pH of the system was lowered from 6.5 to 5.0. In skimmilk at pH 5.0, vegetative cells failed to multiply and spore germination ceased. In Cheddar cheese manufacture, B. cereus multiplied rapidly during the period from the end of cooking to milling of the curd. B. cereus survived in the spore state in Cheddar cheese during 52 weeks curing.Keywords
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