Study of near-infrared imaging spectroscopy for the inspection of peeled potato tubers

In this paper imaging spectroscopy in the near-infrared wavelength range (900 nm-2500 nm) is evaluated for the inspection of peeled potato tubers. The high spectral resolution of the acquired data and the use of the near-infrared wavelength range make it possible to detect defects that are not visible to the human eye. The main inspection goal is the detection of potato tubers with defects that may influence the quality of French fries. The defects of interest are remains of peel, discoloration and water-, starch- or sugar distributions of the potato tubers. In this work we focus on the detection of increased sugar concentrations inside the potato which lead to an undesirable browning during the frying process. Multivariate statistical methods are used to discriminate between the pixel spectra for the defect regions and those for the remaining non-defect regions. The measurement setup and preliminary results of the data analysis are presented.