Development and validation of predictive models for the effect of storage temperature and pH on the growth boundaries and kinetics of Alicyclobacillus acidoterrestris ATCC 49025 in fruit drinks.
Food Microbiol
; 74: 40-49, 2018 Sep.
Article
em En
| MEDLINE
| ID: mdl-29706336
ABSTRACT
This study was undertaken to provide quantitative tools for predicting the behavior of the spoilage bacterium Alicyclobacillus acidoterrestris ATCC 49025 in fruit drinks. In the first part of the study, a growth/no growth interface model was developed, predicting the probability of growth as a function of temperature and pH. For this purpose, the growth ability of A. acidoterrestris was studied at different combinations of temperature (15-45⯰C) and pH (2.02-5.05). The minimum pH and temperature where growth was observed was 2.52 (at 35 and 45⯰C) and 25⯰C (at pHâ¯≥â¯3.32), respectively. Then a logistic polynomial regression model was fitted to the binary data (0 no growth, 1 growth) and, based on the concordance index (98.8%) and the Hosmer-Lemeshow statistic (6.226, Pâ¯=â¯0.622), a satisfactory goodness of fit was demonstrated. In the second part of the study, the effects of temperature (25-55⯰C) and pH (3.03-5.53) on A. acidoterrestris growth rate were investigated and quantitatively described using the cardinal temperature model with inflection and the cardinal pH model, respectively. The estimated values for the cardinal parameters Tmin, Tmax, Topt and pHmin, pHmax, pHopt were 18.11, 55.68, 48.60⯰C and 2.93, 5.90, 4.22, respectively. The developed models were validated against growth data of A. acidoterrestris obtained in eight commercial pasteurized fruit drinks. The validation results showed a good performance of both models. In all cases where the growth/no growth interface model predicted a probability lower than 0.5, A. acidoterrestris was, indeed, not able to grow in the tested fruit drinks; similarly, when the model predicted a probability above 0.9, growth was observed in all cases. A good agreement was also observed between growth predicted by the kinetic model and the observed kinetics of A. acidoterrestris in fruit drinks at both static and dynamic temperature conditions.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Temperatura
/
Armazenamento de Alimentos
/
Alicyclobacillus
/
Sucos de Frutas e Vegetais
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Microbiologia de Alimentos
/
Concentração de Íons de Hidrogênio
Tipo de estudo:
Prognostic_studies
/
Risk_factors_studies
Idioma:
En
Revista:
Food Microbiol
Assunto da revista:
CIENCIAS DA NUTRICAO
/
MICROBIOLOGIA
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Grécia