Institute for Multidisciplinary Research, University of Belgrade, P.O. Box 33, Belgrade, 11030, Serbia.
Maize Research Institute, Zemun Polje, Slobodana Bajića 1, Belgrade, 11185, Serbia.
J Fluoresc. 2018 May;28(3):729-733. doi: 10.1007/s10895-018-2246-z. Epub 2018 Jun 22.
In this preliminary study, we used the Multivariate Curve Resolution- Alternating Least Squares (MCR-ALS) algorithm to analyze the excitation-emission matrix for different samples of maize flour contaminated with aflatoxin B1 (AFB1) - uncontaminated, low-contaminated, high-contaminated and flour from the local market. We intended to see if there are differences in emission spectral parameters that depend on degree of contamination. The analysis used genuine emission of the fluorophores in the flour, in absence and presence of AFB1, which enables fast screening of the samples, without sample pre-processing. As a result of the analysis, two fluorescence components were derived from the emission spectra for all analyzed samples. The components' positions were the same for the uncontaminated reference sample and the commercial flour sample from the local market, whereas for the samples contaminated with the aflatoxin B1, the emitted peaks' positions were red-shifted. We found that the ratio of the areas of these two components is proportional to the intensity of contamination: 0.071 for uncontaminated sample, 0.090 for the sample from local market, 0.192 for low-contaminated sample and 1.431 for high-contaminated sample. These results indicate that fluorescence EEM coupled with MCR-ALS could be used for rapid and simple estimation of the degree AFB1 contamination in maize flour.
在这项初步研究中，我们使用多元曲线分辨-交替最小二乘法（MCR-ALS）算法分析了不同玉米粉样本的激发-发射矩阵，这些样本分别受到黄曲霉毒素 B1（AFB1）的污染（未污染、轻度污染、重度污染）和来自当地市场的玉米粉。我们旨在观察发射光谱参数是否存在依赖于污染程度的差异。该分析使用了玉米粉中荧光团的真实发射，无论是否存在 AFB1，这都可以实现对样品的快速筛选，而无需对样品进行预处理。分析结果得出，对于所有分析样本的发射光谱都衍生出了两个荧光成分。对于未污染的参考样本和来自当地市场的商业玉米粉样本，这些成分的位置是相同的，而对于受到黄曲霉毒素 B1 污染的样本，发射峰的位置发生了红移。我们发现，这两个成分的面积比与污染强度成正比：未污染样本为 0.071，来自当地市场的样本为 0.090，轻度污染样本为 0.192，重度污染样本为 1.431。这些结果表明，荧光 EEM 与 MCR-ALS 相结合可用于快速简单地估计玉米粉中 AFB1 污染的程度。
