Discrimination of teas based on total luminescence spectroscopy and pattern recognition

This paper reports on the application of total luminescence spectroscopy to discriminate between seven different types of tea. Bottled liquid teas; Oolong tea, Green tea, Houji tea, Japanese black tea and tea leaves (Kenya tea, Assam tea and Ceylon tea). Total luminescence spectra were recorded by measuring the emission spectra in the range 300nm to 700 nm at excitation wavelengths from 250 nm to 590nm. Discrimination of teas based on their spectral data was performed by principal component analysis (PCA) a common chemometric technique used for data reduction and visualisation. The results demonstrate the ability of fluorescence techniques to differentiate between green tea (Unfermented), black tea (fermented) and oolong tea (partially fermented).