Single wheat kernel size effects on near-infrared reflectance spectra and color classification

An optical radiation measurement system was used to measure reflectance spe ctra of single wheat kernels from 400 to 2,000 nm. Five classes of wheat we re used for this study. Three kernel sizes (large, medium, and small) were used to determine how wheat kernel size affects visible and near-infrared ( NIR) reflectance spectra and single wheat kernel color classification. Mean kernel weights ranged from 35.6 to 57.2 mg for large kernels, from 26.9 to 45.0 mg for medium kernels, and from 17.6 to 31.4 mg for small kernels. Th e results showed that wheat kernel size significantly affects visible and N IR reflectance spectra. Determination of the color class of red kernels inc reased in accuracy and that of white kernels decreased in accuracy as kerne l size decreased. Data pretreatments such as multiplicative scatter correct ion (MSC), first or second derivatives, and first or second derivatives wit h MSC reduced the effect of kernel size on reflectance spectra and color cl assification.