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MODELING TEMPERATURE, pH, NaCl, NITRITE AND LACTATE ON THE SURVIVAL OF ESCHERICHIA COLI O157:H7 IN BROTH
Author(s) -
WHITING R.C.,
GOLDEN M.H.
Publication year - 2003
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.1745-4565.2003.tb00352.x
Subject(s) - escherichia coli , nitrite , strain (injury) , confidence interval , chemistry , linear regression , food science , zoology , microbiology and biotechnology , biology , nitrate , mathematics , statistics , biochemistry , ecology , anatomy , gene
A model was developed to estimate the survival times for a four‐strain cocktail of Escherichia coli O157:H7 in BHI broths with pH values from 3.5 to 7.0, NaCl from 0.5 to 15%, Na lactate from 0.0 to 2.0% and NaNO 2 from 0 to 75 ppm. Broths were stored between 4 and 37C for up to 6 months. Samples were removed and enumerated at appropriate intervals. A primary level model with a shoulder period (no decline) and a subsequent log‐linear decline was fitted to the survival data and the times for 3, 4, 5, and 6 log 10 ‐units of decline determined. A secondary level second‐order regression equation with the environmental conditions and declines being the independent variables was fitted to the survival times. Confidence limits about the estimated mean were also estimated. In foods with equivalent conditions that do not permit E. coli O157:H7 growth, this model provides an initial estimate of the survival times.