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Evaluation of Oolong Teas Using 1 H and 13 C Solid‐state NMR , Sensory Analysis, and Multivariate Statistics
Author(s) -
Cai Honghao,
Cheng Renhao,
Jin Yali,
Ding Shangwu,
Chen Zhong
Publication year - 2016
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.201600183
Subject(s) - chemistry , quantitative descriptive analysis , magic angle spinning , partial least squares regression , nmr spectra database , nuclear magnetic resonance spectroscopy , analytical chemistry (journal) , chromatography , food science , stereochemistry , aroma , spectral line , statistics , mathematics , physics , astronomy
The classification of Wuyi rock tea (Oolong type) is performed by solid‐state nuclear magnetic resonance ( NMR ) for the first time. Quality differences of eight Oolong teas grown in Wuyi Mountains in southeastern China are analyzed by a combination of solid‐state 1 H and 1 H– 13 C CP‐MAS (cross‐polarization magic angle spinning) NMR , partial least‐squares discriminate analysis ( PLS‐DA ), and quantitative descriptive analysis ( QDA ). The contents of caffeine, carbohydrate, polyphenol, and terpenoid were distinguished, and quantification of the metabolites was made based on the 1 H and 13 C MAS spectra. PLS‐DA shows a separation of high‐ and low‐quality Oolong teas, in good agreement with the result of QDA . These results indicate that NMR metabolomic approach enables us to differentiate the analyzed teas based on their chemical composition.