Segregating red and white wheat visually and with a tristimulus colour meter

Abstract

With red-grained wheat now being grown in Australia in some places, there is a need to segregate it from white grain at the silo to avoid loss of milling and end-use quality. The Minolta tristimulus colour meter and visual inspection have been assessed as possible means to facilitate this segregation. Using only reflected light for sample illumination, 86% of a restricted sample set were correctly classified visually, and 95% of all samples using the Minolta meter. These values were increased to up to 99% in both cases by additionally using transmitted light to illuminate the samples. Thus both the Minolta and visual methods that included alternate use of both illuminant sources provided good segregation of red and white wheat samples. Sample transillumination was particularly helpful for classifying vitreous white grain, and also red grain that had been bleached by rain.