2010 Volume 2010 Issue 110 Pages 110_37-110_47
Quality of special local tea produced in Western Kyushu Island, Kamairicha (pan fired tea) and Tama-Ryokucha (steamed tea), has been traditionally evaluated by visual judgment. Physical appearance and luster of crude tea, and brewed tea color are important evaluation items for quality. In this study a methodology of spectral reflectance and transmittance was discussed to be used for evaluating the tea quality of luster and brewed tea color instead of the visual evaluation.
The reflectance spectra of luster of crude teas which were divided by visual evaluation of leaf flaw denoted the same tendency regardless of tea kinds, however, the spectra correctly discriminated the leaf flaws at a probability of c.a. 100% as a result of canonical discriminant analysis. In addition, the transmittance spectra also discriminated the colors of brewed tea of both Kamairicha and Tama-Ryokucha at a probability of 100%. Therefore it appears that a numerical conversion of visual evaluation for the leaf flaw and the colors of brewed tea by using the methodology of spectral reflectance and transmittance can be available.
