Laser-induced fluorescence was used to evaluate the classification and quality of Chinese oolong teas and jasmine teas. The fluorescence of four different types of Chinese oolong teas—Guangdong oolong, North Fujian oolong, South Fujian oolong, and Taiwan oolong was recorded and singular value decomposition was used to describe the autofluoresence of the tea samples. Linear discriminant analysis was used to train a predictive chemometric model and a leave-one-out methodology was used to classify the types and evaluate the quality of the tea samples. The predicted classification of the oolong teas and the grade of the jasmine teas were estimated using this method. The agreement between the grades evaluated by the tea experts and by the chemometric model shows the potential of this technique to be used for practical assessment of tea grades.
© 2012 Optical Society of America
Original Manuscript: June 15, 2011
Revised Manuscript: December 2, 2011
Manuscript Accepted: December 7, 2011
Published: February 17, 2012
Vol. 7, Iss. 5 Virtual Journal for Biomedical Optics
Liang Mei, Patrik Lundin, Mikkel Brydegaard, Shuying Gong, Desong Tang, Gabriel Somesfalean, Sailing He, and Sune Svanberg, "Tea classification and quality assessment using laser-induced fluorescence and chemometric evaluation," Appl. Opt. 51, 803-811 (2012)