Modelling the effect of temperature and water activity in the growth boundaries of Aspergillus ochraceus and Aspergillus parasiticus
Issue date
2011Suggested citation
García, Daiana;
Ramos Girona, Antonio J.;
Sanchís Almenar, Vicente;
Marín Sillué, Sònia;
.
(2011)
.
Modelling the effect of temperature and water activity in the growth boundaries of Aspergillus ochraceus and Aspergillus parasiticus.
Food Microbiology, 2011, vol. 28, p. 406-417.
https://doi.org/10.1016/j.fm.2010.10.004.
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Show full item recordAbstract
The aim of this work was to model the growth of Aspergillus parasiticus and Aspergillus ochraceus, both
mycotoxin producers, near to the growth/no growth boundaries and validate those models in sterile
maize grain, peanuts and coffee beans. Malt extract agar was adjusted to six different water activities:
0.93, 0.91, 0.89, 0.87, 0.85 and 0.80. Plates were incubated at 10, 15, 20, 25, 30, 37 and 42 C. For each of
the 42 conditions, 10 Petri dishes were inoculated. Both kinetic and probability models were applied to
colony growth data. The results of the present study indicate that the developed probability modelling
approach could be satisfactorily employed to quantify the combined effect of temperature and water
activity on the growth responses of A. ochraceus and A. parasiticus. However, validation of kinetic results
led to poor goodness of prediction. In this study, the validation samples were placed near to the expected
boundaries of the models in order to test them under the worst situation. Probability of growth
prediction under extreme growth conditions was somewhat compromised, but it can be considered
acceptable.