1.4.2 Development of a quartz crystal microbalance sensor array for discrimination of black tea

14th International Meeting on Chemical Sensors - IMCS 2012
2012-05-20 - 2012-05-23
Nürnberg/Nuremberg, Germany
1.4 Sensors Arrays
P. Sharma, A. Ghosh, B. Tudu, R. Bandyopadhyay, A. Chatterjee - Dept. of Instrumentation and Electronics Engineering, Jadavpur University (India), N. Bhattacharyya - Centre for Development of Advanced Computing (India)
114 - 117


Evaluation of aroma quality of tea and its classification is extremely critical from the commercial point of view. The most widely practised method for evaluating the quality of tea is by human sensory panel, called “Tea Tasters”. But this method is very subjective and its accuracy is also uncertain. For this reason various instrumental setups have been investigated in recent times. Electronic Nose is one such device which has been implemented for tea quality evaluation. An electronic nose with an array of quartz crystal microbalance (QCM) sensors has been developed to differentiate among different tea samples. 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 10 MHz Quartz crystal blanks coated with different sensing materials have been used to differentiate the aroma of orthodox and CTC (cut-tear-curl) 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) and by ICA in conjunction with LDA. Comparison of these two techniques is presented by Dunn’s indices. Back-propagation multilayer perceptron (BPMLP) classifier has also been used along with 10-fold cross validation technique for classification of data.