Discrimination of Various Clones of Black Tea Using NIR Spectroscopy

In this work, discrimination of five different clones of black tea viz., TV 20, TV 18, TV 22, TV 23 and mixed clone (a mixture of TV 20, TV 18, TV 22a and TV 23) has been described using near infrared spectroscopy (NIRS). The absorbance spectra of the black tea samples were recorded in the wavelength window of 900 - 1700 nm. Each type of black tea samples provided a signature which has been evaluated using principal component analysis (PCA). For quantitative evaluation of the data nature, class separability index (SI) has been calculated. SI value obtained for the raw NIR spectral data was found to be 17.32 which reflect good separability. Additionally, the distinct and segregated clusters so formed in the PCA score plot using the NIR spectral data reveals that the five clones of black tea can clearly be distinguished using NIR spectroscopy.