title: Predictive model to describe the combined effect of pH and NaCl on apparent heat resistance of Bacillus stearothermophilus.
abstract: The combined effect of pH and NaCl on the apparent thermal resistance of Bacillus stearothermophilus ATCC 12980 spores was studied. Spores were heated at different temperatures (115-125 degrees C) in mushroom substrate, acidified using glucono-delta-lactone to different pH levels (from 5.75 to 6.7), which contained concentrations of NaCl that ranged from 0.5 to 3% (w/v). The recovery medium was acidified to the same pH level and contained the same NaCl concentration as the heating menstruum. A factorial experimental design allowed a predictive model to be developed, which described the combined effect of heating temperature, pH and NaCl on the thermal resistance of B. stearothermophilus spores. Predictions from the model provided a valid description of the data used to generate the model, and agreed with observations from the literature and from an independent experiment performed using asparagus and bean substrates.
authors.affiliation: Instituto de Agroquímica y Tecnología de Alimentos (CSIC), Valencia, Spain.
authors.forename: P M
authors.initials: PM
authors.lastname: Periago
authors.forename: P S
authors.initials: PS
authors.lastname: Fernández
authors.forename: M C
authors.initials: MC
authors.lastname: Salmerón
authors.forename: A
authors.initials: A
authors.lastname: Martínez
mesh_terms: D001411:Geobacillus stearothermophilus / Q000502:physiology*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008954:Models, Biological; D012965:Sodium Chloride / Q000494:pharmacology*
chemical_list: D012965:Sodium Chloride