Faculty of Food Science Technology, Ho Chi Minh city University of Food Industry, 140 Le Trong Tan street, Tay Thanh ward, Tan Phu district, Ho Chi Minh, Viet Nam.
Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, 9000 Ghent, Belgium.
Int J Food Microbiol. 2022 Aug 16;375:109743. doi: 10.1016/j.ijfoodmicro.2022.109743. Epub 2022 May 26.
The growth of Aspergillus flavus 01 (AF01) and Fusarium proliferatum 01 (FP01) was studied on paddy and white rice, using a full factorial design with five temperature levels (20, 25, 30, 35 and 40 °C) and five points of water activity (0.80, 0.85, 0.90, 0.95 and 0.99 a). The maximum radial growth rates (μ, mm.day) and lag times (λ, days) of both fungal strains were estimated by linear regression. When the obtained values were compared with the prediction of reported predictive models for growth of A. flavus 01 and F. proliferatum 01, none of the reported models was able to describe the growth as determined by water activity and temperature adequately. Therefore, new secondary models were developed to describe the obtained fungal radial growth rate of both strains on paddy and white rice as a function of temperature and water activity. The results showed that optimum radial growth rate of AF01 and FP01 were estimated at 0.99 a/35 °C and 0.99 a/30 °C, respectively. Both strains failed to grow at 0.80, 0.85 and 0.90 a at all observed temperatures (except for AF01 at 0.90a/35 °C). Multi-factorial cardinal and General Polynomial models were the best models to describe combined influence of water activity and temperature on fungal growth rate on both matrices with the bias factors of 0.771-1.10 and accuracy factors of 1.102-1.297. These values should be concerned during storage to mitigate fungal growth on paddy and white rice.
研究了在稻谷和精米上，曲霉 01（AF01）和镰刀菌增殖 01（FP01）的生长情况，采用全因子设计，设置 5 个温度水平（20、25、30、35 和 40°C）和 5 个水分活度点（0.80、0.85、0.90、0.95 和 0.99）。通过线性回归估计了两种真菌菌株的最大径向生长速率（μ，mm·day）和滞后时间（λ，天）。将得到的值与报道的预测模型对 AF01 和 FP01 生长的预测值进行比较时，没有一个报道的模型能够充分描述水分活度和温度对生长的预测。因此，开发了新的二次模型来描述两种菌株在稻谷和精米上的真菌径向生长速率，作为温度和水分活度的函数。结果表明，AF01 和 FP01 的最佳径向生长速率分别估计为 0.99 a/35°C 和 0.99 a/30°C。在所有观察到的温度下（AF01 在 0.90 a/35°C 时除外），两种菌株都无法在 0.80、0.85 和 0.90 a 时生长。多因子基数和广义多项式模型是描述水分活度和温度对两种基质上真菌生长速率综合影响的最佳模型，偏差因子为 0.771-1.10，准确度因子为 1.102-1.297。在储存过程中应注意这些值，以减轻稻谷和精米上的真菌生长。
