AUTHENTICATION OF COFFEE BEAN VARIETY BY NEAR-INFRARED REFLECTANCE SPECTROSCOPY OF DRIED EXTRACT

The potential of near-infrared (NIR) reflectance spectroscopy for disc riminating between coffee beverage prepared from pure Arabica, pure Ro busta and blends of these two varieties was investigated. Dried bevera ges were produced by both lyophilisation and air-drying under vacuum o n glass-fibre filter paper. Spectral collections were treated by princ ipal component and factorial discriminant analyses. Using the waveleng th range 1100-2498 nm, only three of 65 test samples were misclassifie d when the filter paper approach was used. When freeze-dried coffee be verages were analysed, nine of the 65 test samples were misclassified. The basis for this discrimination appears to involve caffeine and/or other alkaloids.