Laser Infrared Spectroscopy Towards Sustainable On-Site Detection of Mycotoxins in Cereals

In the time of climate crisis accompanied by global warming and unpredictable rainfalls, even more challenges than before arise in food production. These can be attributed to the growth of plant pathogens in cereals exemplified by species like Fusarium graminearum and Fusarium culmorum. These pathogens produce toxic secondary metabolites known as mycotoxins. One of the prevalent mycotoxins in cereals is deoxynivalenol (DON). The overconsumption of DON leads to several health issues in humans and livestock. Acute exposure to DON results in vomiting, stomachaches, and dizziness. Due to this, DON is considered a global food safety issue. Therefore, there is an increasing demand for methods that facilitate rapid, sustainable, on-site detection of DON. The present study introduces laser infrared (IR) spectroscopy combined with advanced chemometric data evaluation routines and optimized DON extraction strategies from wheat using various solvents. The spectrometer comprises broadly tuneable (1840 – 1525 cm-1) quantum cascade lasers (QCLs), an attenuated total reflection (ATR) element, and a mercury cadmium telluride (MCT) detector. Data mining and outlier detection were conducted using principal component analysis (PCA), while sparse partial least squares discriminant analysis (SPLS-DA) was used for classification. Robust classification models were established discriminating high- and low-contaminated wheat samples according to the EU limit for DON at 1250 μg/kg. Using water as an extraction solvent a classification accuracy of cross-validation of 88% was achieved, while the mixture of ethanol:water (30:70) yielded a classification accuracy of cross-validation of 92 %. Thereby, the achieved results showcase that laser IR spectroscopy reveals mycotoxin detection as a sustainable process by utilizing environmentally friendly solvents. Employing QCLs as a light source enables portability of the device, which facilitates on-site detection of mycotoxins.