Electronic nose with quartz crystal microbalance sensors to discriminate Indian black tea varieties

An electronic nose with an array of quartz crystal microbalance (QCM) sensors has been developed to discriminate among different samples of Indian black tea varieties. The important volatile organic components (VOC) responsible for aroma of tea have been considered and the corresponding sensing materials have been identified. Five AT-cut 10MHz Quartz crystal blanks coated with different sensing materials have been used to differentiate the aroma of orthodox and CTC (cut-tearcurl) tea samples. The developed sensors can distinguish not only between the orthodox and CTC tea but distinct clusters are also obtained for the four different tea-samples, as visualized through principal component analysis (PCA). A radial basis function network (RBF) classifier has been used along with 10-fold cross validation technique for classification of data.