Evaluation of Oolong Teas Using 1H and 13C Solid‐state NMR, Sensory Analysis, and Multivariate Statistics. Issue 9 (18th August 2016)

• Record Type: Journal Article
• Authors: Cai, Honghao; Cheng, Renhao; Jin, Yali; Ding, Shangwu; Chen, Zhong
• Is Part Of: Journal of the Chinese Chemical Society. Volume 63:Issue 9(2016:Sep.)
• Page Start: 792
• Page End: 799
• Publication Date: 2016-08-18
• Subjects: Carbon -- Nuclear magnetic resonance spectroscopy -- Oolong tea -- Sensory evaluation -- Partial least‐squares discriminate analysis -- Quality of tea -- Cross‐polarization magic angle spinning; Chemistry -- Periodicals; Electronic journals; 540.5
• DOI: 10.1002/jccs.201600183
• Languages: English
• ISSNs: 0009-4536

Abstract

Abstract : 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. Abstract : Solid state magic angle spin is applied to obtain NMR spectra of Oolong tea. By combing with partial least‐squares discriminate analysis and quantitative descriptive analysis, quality classification of Oolong tea is performed based on the NMR data.