Use of the Gompertz equation to model non-linear survival curves and predict temperature, pH, and sodium chloride effects for Listeria monocytogenes Scott A

Numerous examples of non-linear survival curves, plotted as log surviving cells vs. time, for bacteria exposed to heat have been reported. Factors which may affect the shape of a survival curve and the heat resistance of bacteria include temperature, pH, and NaCl concentration. Many studies have examined the effect of these factors individually, but little information exists on the combined effects. The objective of this study was to mathematically model non-linear survival curves to account for these factors and their interactions simultaneously. Heat resistance of <u>Listeria monocytogenes</u>(L. <u>monocytogenes</u>) was determined in O.lM KH₂P0₄ buffer and in infant formula at three temperatures (50, 55, and 60 C), three pH levels (5, 6, and 7), and three NaCl concentrations (0, 2, 4%). Survival curves were fit using linear regression, non-linear regression with a modified logistic equation, and non-linear regression with a modified Gompertz equation.

Name thesis:degree_name

Ph. D.

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Food Science and Technology

Department dc:contributor.department

Food Science and Technology

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1994

Author dc:creator

• Linton, Richard Howard

Committee members dc:contributor.committeemember

• Pierson, Merle D.
• Hackney, Cameron Raj
• Johnson, Janet M.
• Marcy, Joseph E.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

etd-06062008-164544

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/27971