Food Technology Department, Lleida University, XaRTA-UTPV, Rovira Roure 191, 25198 Lleida, Spain.
Food Microbiol. 2011 May;28(3):406-17. doi: 10.1016/j.fm.2010.10.004. Epub 2010 Oct 19.
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.
本研究的目的是在接近生长/不生长边界的条件下对产毒素真菌寄生曲霉和杂色曲霉的生长进行建模，并在无菌玉米籽粒、花生和咖啡豆中对这些模型进行验证。麦芽提取物琼脂的水活度调整为 0.93、0.91、0.89、0.87、0.85 和 0.80 共 6 个不同水平。平板在 10、15、20、25、30、37 和 42°C 下进行孵育。对于 42 种条件中的每一种，都接种了 10 个培养皿。对菌落生长数据同时应用了动力学和概率模型。本研究的结果表明，所开发的概率建模方法可以令人满意地用于量化温度和水活度对杂色曲霉和寄生曲霉生长反应的综合影响。然而，对动力学结果的验证导致预测的准确性较差。在本研究中，验证样本被放置在模型预期边界附近，以便在最不利的条件下对其进行测试。在极端生长条件下进行生长预测的可能性有些妥协，但可以认为是可以接受的。
