Fast determination of carrot quality by spectroscopy methods in the UV-VIS,NIR and IR range.

Some optical spectroscopic methods are able to determine the main quality parameters of fresh carrots in a fast and nondestructive manner. Reflection measurements in the visible range and the use of colorimetric calculations supply characteristic colour coordinates and evaluation of the colour homogeneity of a specific variety. Near infrared spectroscopy (NIRS) in combination with multivariate regression, e.g. the method of partial least squares (PLS), provide a fast and nondestructive method to predict the contents of a-carotene, ß-carotene and dry matter content. Measurements of carrot juice samples in the mid-infrared range (MIR) applying a diamond-ATRequipment and PLS-algorithm for chemometric interpretation supply reliable predictions of sugar contents. The application of Raman spectroscopy on carrot slices and the method of Raman mapping reveals the relative carotenoid distribution in cross sections of various carrot roots.