Determining vitreousness of durum wheat kernels using near infrared hyperspectral imaging

Vitreousness is an important grading factor for durum wheat kernel that is associated with protein content. The European Union (EU) regulations stipulate the use of a visual method to determine the vitreousness rate. However, some authors have been interested in the development of automatic and non-destructive methods based on near infrared spectroscopy or digital imaging technology. In this paper, we propose to couple spectroscopy and digital imaging technology and, thus, to analyse the potential of a near infrared hyperspectral imaging system to classify wheat kernels by their vitreousness. Hyperspectral reflectance images of wheat kernel at different vitreousness rates have been achieved (wavelength range: 650-1100 nm). A discrimination method using latent variables from partial least squares has enabled satisfactory discrimination results to be obtained: perfect separation between vitreous and non-vitreous kernels and a classification rate reaching up to 94% for the discrimination of total and partial starchy kernel classes.