Effect of storage temperature on the lag time of Geobacillus stearothermophilus individual spores
Author
dc.contributor.author
Kakagianni, Myrsini
Author
dc.contributor.author
Aguirre Garcia, Juan Salvador
Author
dc.contributor.author
Lianou, Alexandra
Author
dc.contributor.author
Koutsoumanis, Konstantinos P.
Admission date
dc.date.accessioned
2018-05-25T15:09:35Z
Available date
dc.date.available
2018-05-25T15:09:35Z
Publication date
dc.date.issued
2017
Cita de ítem
dc.identifier.citation
Food Microbiology 67 (2017) 76-84
es_ES
Identifier
dc.identifier.other
10.1016/j.fm.2017.04.009
Identifier
dc.identifier.uri
https://repositorio.uchile.cl/handle/2250/148139
Abstract
dc.description.abstract
The lag times (lambda) of Geobacillus stearothermophilus single spores were studied at different storage temperatures ranging from 45 to 59 degrees C using the Bioscreen C method. A significant variability of lambda was observed among individual spores at all temperatures tested. The storage temperature affected both the position and the spread of the lambda distributions. The minimum mean value of lambda (i.e. 10.87 h) was observed at 55 degrees C, while moving away from this temperature resulted in an increase for both the mean and standard deviation of lambda, A Cardinal Model with Inflection (CMI) was fitted to the reverse mean lambda, and the estimated values for the cardinal parameters T-min, T-max, T-opt and the optimum mean lambda of G. stearothermophilus were found to be 38.1, 64.2, 53.6 degrees C and 10.3 h, respectively. To interpret the observations, a probabilistic growth model for G. stearothermophilus individual spores, taking into account lambda variability, was developed. The model describes the growth of a population, initially consisting of No spores, over time as the sum of cells in each of the N-0 imminent subpopulations originating from a single spore. Growth simulations for different initial contamination levels showed that for low N-0 the number of cells in the population at any time is highly variable. An increase in N-0 to levels exceeding 100 spores results in a significant decrease of the above variability and a shorter lambda of the population. Considering that the number of G. stearothermophilus surviving spores in the final product is usually very low, the data provided in this work can be used to evaluate the probability distribution of the time-to-spoilage and enable decision-making based on the "acceptable level of risk".
es_ES
Patrocinador
dc.description.sponsorship
Understanding the impact of manufacturing processes in the ecology /
European Social Fund (ESF)