Cross-polarised VNIR hyperspectral reflectance imaging system for agrifood products

Hyperspectral reflectance imaging using unpolarised light has high potential for various applications in non-destructive quality evaluation of food and agricultural products. However, one of the most important challenges is the existence of glare in the obtained hyperspectral reflectance images due to specular reflection of the illuminating light on the sample surface. Whilst this can be avoided for flat surfaces by optimising the viewing angle, this is not possible for curved food products. Therefore, cross-polarisation has been implemented in this study to block the specular reflection and exclude it from the acquired hyperspectral reflectance images in the 450–1000 nm range. The added value of this approach has been successfully demonstrated for three glossy agricultural products: aubergine and two apple cultivars, for which the quality of the obtained hyperspectral images, expressed by signal-to-noise ratios, could be improved from 1.1 to 3 times depending on the wavelength regions. •Cross-polarised hyperspectral reflectance imaging developed for glossy agrifood.•Glare regions receded for hyperspectral reflectance images of aubergine and apples.•Cross-polarised hyperspectral reflectance images had better signal-to-noise ratios.