One common phenomenon which continues to plague grain farmers relates to the infestation of whole grain seeds with a disease such as, for example, Fusarium. This in turn causes a small percentage of grain kernels to contain a high level of a mycotoxin that is inhomogeneously distributed within random samples of the grain.
Deoxynivalenol (hereinafter referred to as “DON” or “Vomitoxin”) is one of the toxic 12,13-epoxytrichothecenes produced by various species of Fusarium, especially F. graminearum. The presence of DON typically occurs in barley, wheat and other feed grains that are grown under certain climatic conditions. As a result, the quality of beer can be adversely affected when malting barley containing significant concentrations of DON is used. Moreover, illnesses have been observed in livestock that have consumed feed grains containing high levels of DON concentration. Consequently, wheat and barley lots are oftentimes discounted in value when sold on the open market, as soon as it is detected that DON concentrations present in those lots exceed certain predetermined levels. Hence, due to the significant economic issue involved, the accuracy and precision of DON measurements sampled from grain lots is of great financial concern.
Currently, levels of DON are typically measured in the marketing channels with commercially available test kits, based on enzyme linked immunosorbent assay (ELISA) technology. This method requires the use of a series of procedures/steps including grinding, cleaning and extraction. Due to the toxicity of DON, only qualified technicians are capable of running these tests. Although this method of analysis for DON is currently the grain industry standard, its tedious nature make it difficult, if not impossible, to perform quick and easy analyses out in the field. Clearly, therefore, there is a significant need in the grain industry for alternative methods of DON analysis which enable accurate analyses to be performed, in the field, quickly, easily and in a nondestructive manner.
Near infrared analysis has been used successfully in the grain industry for protein and moisture content analyses. There have been reports regarding the use of NIR and FTIR to perform DON analyses. However, in those cases FTIR was not used by itself, but rather as a detector in combination with gas chromatography. As for the use of NIR, reports have indicated the inability to detect DON at low ppm levels, which are commonplace, due to the inhomogeneous distribution of the infected kernels.