Discriminant analysis of black tea by near infrared reflectance spectroscopy

A new method for the discrimination of commercial black tea samples using near infrared (NIR) reflectance spectroscopy has been investigated. NIR data at four wavelengths (1660, 1720, 2050 and 2300 nm) corresponding to maximum variation in the intensity of absorption bands in the spectra of black teas were used to calculate Mahalanobis distances. A cut-off point in the values of these distances was determined by means of which two sets of black teas with differing sensory properties could be discriminated with a 91% success rate.