High hydrostatic pressure inactivation of Salmonella typhimurium: effects of pressure, duration, pH and temperature studied by analysis of variance.
High hydrostatic pressure treatments are regarded as possible alternative methods for food preservation. One of the primary considerations for industrial applications is the ability of these methods to eradicate pathogenic microorganisms. This study subjected S. typhimurium suspensions, first in a phosphate buffer (pH 7.0) and then in a citrate phosphate buffer (pH 5.6), to high hydrostatic pressure treatments relative to the following variables: pressure (200-400 MPa), duration (3, 10 and 20 min), temperature (4, 20 and 40 degrees C) and the pH of the suspension medium (5.6 and 7.0). An optimal design of 40 runs was obtained using the Fedorov algorithm, and responses were studied by analysis of variance in terms of cell survival on plate count agar. Efficiency was determined by Log10 comparisons of the numbers of live cells before and after treatment. A statistically significant relationship was found between the four variables considered (pressure, pH, duration and temperature), their interactions (duration x pressure, pH x temperature, pH x pressure) and the inactivation of S. typhimurium. R-squared statistical analysis indicated that the linear model used accounted for more than 98% of the variability in the inactivation of S. typhimurium.
Ritz
M
M
Unité associée Inra d'hygiène alimentaire, Ecole nationale vétérinaire de Nantes, France.
Courcoux
P
P
Semenou
M
M
Federighi
M
M
D000465:Algorithms; D000704:Analysis of Variance; D005516:Food Microbiology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006874:Hydrostatic Pressure; D012480:Salmonella Infections / Q000517:prevention & control* / Q000635:transmission; D012486:Salmonella typhimurium / Q000254:growth & development*; D013997:Time Factors