基于电子鼻技术的糙米黄曲霉毒素污染快速检测方法研究

Rapid Detection of Aflatoxin Contamination in Brown Rice Based on Electronic Nose Technology

为验证电子鼻技术用于粮食真菌毒素污染快速检测的可行性,本研究利用Fox3000型电子鼻对受黄曲霉毒素侵染的糙米样品的挥发性物质进行了检测分析,建立了电子鼻响应信号与黄曲霉毒素水平的相关关系模型。结果显示,偏最小二乘判别分析(PLS-DA)法可较好区分不同黄曲霉毒素含量水平的糙米样品,模型的留一交互验证正确率高于80%。PLS回归分析显示电子鼻响应信号与糙米中黄曲霉毒素B_1、B_2、G_1、G_2及总量之间呈现较高相关性,其中对黄曲霉毒素B1的预测精度最高,预测相关系数和均方根误差分别达到0.808和127.3μg/kg。进一步,通过对电子鼻各气体传感器响应信号的载荷分析确定了各传感器贡献率的差异,结合气相色谱-质谱联用(GC-MS)技术揭示了受黄曲霉毒素污染糙米样品的挥发性组分的变化主要体现在酮醛类、醇类、芳香烃类和烷烃类上。结果表明,利用电子鼻对糙米的黄曲霉毒素污染的快速检测具有一定可行性,为粮食真菌毒素污染的早期预警提供一种新思路和新方法。

In order to explore the feasibility use of electronic nose （ E - nose） for mycotoxin contamination detection in grain, the analysis for volatile compounds of brown rice contaminated with aflatoxin was carried out using a Fox 3000 E -nose system. The corresponding correlation models between aflatoxin levels in brown rice and the responses of E - nose signals were established. The results showed that samples contaminated with different levels of aflatoxin could be distinguished by partial least square- discriminant analysis （PLS -DA） algorithm, and the overall correct classification rate in leave -one -out cross validation was over 80%. In addition, good calibration statistics were obtained for the prediction of aflatoxin B1 , B2, G1 , G2 and total aflatoxins in samples by PLS regression analysis. The best result was obtained for aflatoxin B1. The correlation coefficient and root - mean - square error of prediction obtained was 0.808 and 127.3 μg/kg, respectively. Further, the contribution rate of E -nose sensors was re- vealed by loadings analysis. Gas chromatography -mass spectroscopy （GC -MS） indicated that the changes in volatile compounds of aflatoxin -contamination samples could be mainly attributed to ketones, aldehydes, alcohols, aromatics and alkanes. Overall, the results demonstrated that E - nose offered the feasibility as a rapid tool for the screening of aflatoxin - contamination in brown rice. This methodology provided a new idea and approach for early detection of mycotoxin contamination in grain.