Geographical Origin Discrimination of Oolong Tea (TieGuanYin, Camellia sinensis (L.) O. Kuntze) Using Proton Nuclear Magnetic Resonance Spectroscopy and Near-Infrared Spectroscopy

Abstract

A total of 90 oolong tea samples were collected from three different growing places in the Fujian province of China. Both proton nuclear magnetic resonance (1H NMR) and near-infrared spectroscopy (NIR) were used to analyze the collected tea samples. With the aid of chemometric methods, differential components in 1H NMR data and characteristic wavenumbers from NIR spectra were identified. Since NMR and NIR provide complementary information for tea samples, data fusion was carried out by combining 1H NMR and NIR spectra of the collected tea sample. Experimental results showed that a better discrimination accuracy of geographical origins of oolong tea could be achieved by combining NMR and NIR data (86.2–95.8%), as compared to using NMR data (68.2–78.7%) or NIR data (80.0–89.3%) alone. The current data suggested that a combination of NMR and NIR methods could serve as an efficient way for geographical origin discrimination and qualitative control of oolong tea.