Effect of temperature and water activity on growth and ochratoxin A production boundaries of two Aspergillus carbonarius isolates on a simulated grape juice medium

dc.contributor.author	Tassou, CC	en
dc.contributor.author	Natskoulis, PI	en
dc.contributor.author	Magan, N	en
dc.contributor.author	Panagou, EZ	en
dc.date.accessioned	2014-06-06T06:49:21Z
dc.date.available	2014-06-06T06:49:21Z
dc.date.issued	2009	en
dc.identifier.issn	13645072	en
dc.identifier.uri	http://dx.doi.org/10.1111/j.1365-2672.2009.04203.x	en
dc.identifier.uri	http://62.217.125.90/xmlui/handle/123456789/4543
dc.subject	Aspergillus carbonarius	en
dc.subject	Fungal growth	en
dc.subject	Ochratoxin A	en
dc.subject	Predictive mycology	en
dc.subject	Probabilistic models	en
dc.subject	Wine grapes	en
dc.subject.other	ochratoxin	en
dc.subject.other	water	en
dc.subject.other	fungus	en
dc.subject.other	growth response	en
dc.subject.other	incubation	en
dc.subject.other	model validation	en
dc.subject.other	temperature effect	en
dc.subject.other	analytical error	en
dc.subject.other	article	en
dc.subject.other	Aspergillus	en
dc.subject.other	aspergillus carbonarius	en
dc.subject.other	controlled study	en
dc.subject.other	culture medium	en
dc.subject.other	fungus growth	en
dc.subject.other	grape juice	en
dc.subject.other	incubation temperature	en
dc.subject.other	logistic regression analysis	en
dc.subject.other	nonhuman	en
dc.subject.other	simulation	en
dc.subject.other	statistical model	en
dc.subject.other	temperature dependence	en
dc.subject.other	Aspergillus	en
dc.subject.other	Beverages	en
dc.subject.other	Culture Media	en
dc.subject.other	Food Microbiology	en
dc.subject.other	Logistic Models	en
dc.subject.other	Models, Biological	en
dc.subject.other	Ochratoxins	en
dc.subject.other	Temperature	en
dc.subject.other	Vitis	en
dc.subject.other	Water	en
dc.subject.other	Aspergillus carbonarius	en
dc.subject.other	Vitaceae	en
dc.subject.other	Vitis vinifera	en
dc.title	Effect of temperature and water activity on growth and ochratoxin A production boundaries of two Aspergillus carbonarius isolates on a simulated grape juice medium	en
heal.type	journalArticle	en
heal.identifier.primary	10.1111/j.1365-2672.2009.04203.x	en
heal.publicationDate	2009	en
heal.abstract	Aims: To develop and validate a logistic regression model to predict the growth and ochratoxin A (OTA) production boundaries of two Aspergillus carbonarius isolates on a synthetic grape juice medium as a function of temperature and water activity (aw). Methods and Results: A full factorial design was followed between the factors considered. The aw levels assayed were 0·850, 0·880, 0·900, 0·920, 0·940, 0·960, 0·980 and the incubation temperatures were 10, 15, 20, 25, 30, 35 and 40°C. Growth and OTA production responses were evaluated for a period of 25 days. Regarding growth boundaries, the degree of agreement between predictions and observations was >99% concordant for both isolates. The erroneously predicted growth cases were 3·4-4·1% false-positives and 0·7-1·4% false-negatives. No growth was observed at 10°C and 40°C for all aw levels assayed, with the exception of 0·980 aw/40°C, where weak growth was observed. Similarly, OTA production was correctly predicted with a concordance rate >98% for the two isolates with 0·7-1·4% accounting for false-positives and 2·0-2·7% false-negatives. No OTA production was detected at 10°C or 40°C regardless of aw, and at 0·850 aw at all incubation temperatures. With respect to time, the OTA production boundary shifted to lower temperatures (15-20°C) as opposed to the growth boundary that shifted to higher temperature levels (25-30°C). Using two literature datasets for growth and OTA production of A. carbonarius on the same growth medium, the logistic model gave one false-positive and three false-negative predictions out of 68 growth cases and 13 false-positive predictions out of 45 OTA production cases. Conclusions: The results of this study suggest that the logistic regression model can be successfully used to predict growth and OTA production interfaces for A. carbonarius in relation to temperature and aw. Significance and Impact of the Study: The proposed modelling approach helps the understanding of fungal-food ecosystem relations and it could be employed in risk analysis implementation plans to predict the risk of contamination of grapes and grape products by A. carbonarius. © 2009 The Society for Applied Microbiology.	en
heal.journalName	Journal of Applied Microbiology	en
dc.identifier.issue	1	en
dc.identifier.volume	107	en
dc.identifier.doi	10.1111/j.1365-2672.2009.04203.x	en
dc.identifier.spage	257	en
dc.identifier.epage	268	en