Feasibility of FT–Raman spectroscopy for rapid screening for DON toxin in ground wheat and barley

Abstract

Rapid detection of deoxynivalenol (DON) in cereal-based food and feed has long been the goal of regulators and manufacturers. As non-destructive approaches, infrared (IR) and near-infrared (NIR) spectroscopic techniques have been used for the prediction and classification of contaminated single-kernel and ground grain without any DON extraction steps. These methods, however, are hindered by the intense and broad spectral bands attributed to naturally occurring moisture. Raman spectroscopy could be an alternative to IR and NIR due to its insensitivity to water and fewer overlapped bands. This study explored the feasibility of the Raman technique for rapid and non-destructive screening of DON-contaminated wheat and barley meal. The advantages of this technique include the use of a 1064-nm NIR excitation laser that reduces interference from fluorescence of biological compounds in wheat and barley, the use of a simple intensity–intensity algorithm at two unique frequencies, plus the technique's ease of sample preparation. The results indicate that the simple algorithm, as well as principal component analysis applied to the Raman spectra, can be used to classify low from high DON grain.

Keywords:

• analysis
• NIR
• screening
• mycotoxins
• Fusarium
• cereals and grain

Acknowledgements

The authors wish to express their sincere thanks to Dr Richard Horsley and Dr Paul Schwartz of Department of Plant Sciences, North Dakota State University, for barley samples and DON analysis. One of us (YD) acknowledges financial aid from the Wheat and Barley Scab Initiative of the USDA. Mention of a product or specific equipment does not constitute a guarantee or warranty by the US Department of Agriculture and does not imply its approval to the exclusion of other products that may also be suitable.