ARS | Publication request: Infrared spectral properties of germ, pericarp, and endosperm sections of sound wheat kernels and those damaged by Fusarium graminearum

Submitted to: Applied Spectroscopy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 30, 2012
Publication Date: September 1, 2012
Citation: Peiris, K.S., Bockus, W.W., Dowell, F.E. 2012. Infrared spectral properties of germ, pericarp, and endosperm sections of sound wheat kernels and those damaged by Fusarium graminearum. Applied Spectroscopy. 66(9):1053-1060.

Interpretive Summary: Fusarium head blight (FHB) is a fungal disease of wheat and other small grain cereals that can reduce grain yield and quality when warm, humid weather conditions are experienced at the time of flowering. The food and feed prepared from Fusarium-damaged grains pose a health risk to humans and animals due to the presence of mycotoxins. We studied the pericarp, germ, and endosperm individual grain kernels to determine the mycotoxins and fungi in each component using infrared spectroscopy. We found large differences in the pericarp and germ of infected and uninfected kernels, but little difference in the endosperm. These results show that infrared spectroscopy can be used to study where fungi and mycotoxins are concentrated in individual kernels. This will help wheat breeders study resistance mechanisms, and processors determine ways to reduce fungi and toxins in flour.

Technical Abstract: Mid-infrared attenuated total reflectance (MIR-ATR) spectra (4000-380 cm-1) of pericarp, germ, and endosperm sections from sound and Fusarium-damaged wheat kernels of cultivars Everest and Tomahawk were collected using a Fourier Transform Infrared (FTIR) spectrometer. The differences in infrared absorption bands between sound and Fusarium-damaged kernels were examined. Absorption bands in which differences were identified were compared with the MIR-ATR absorption bands of deoxynivalenol (DON) and Fusarium graminearum hyphae. Marked differences in absorption patterns were observed between sound and Fusarium-damaged pericarp and germ spectra, whereas those differences were negligible in the endosperm spectra. Fusarium-damaged pericarp and germ spectra exhibited a shift in the peak position of the band near 1035 cm-1 along with increased absorptions at 1160, 1203, 1313, and 1375 cm-1, likely due to the influence of DON and fungi in the Fusarium-damaged kernel tissue matrix. These results suggest that infrared spectroscopy can detect DON in the surface tissues of Fusarium-damaged wheat kernels.