Regionality is a term used in the tea industry to describe the particular style of tea produced by a growing region. Determining the characteristics of the tea of specific regions can help growers predict tea plant quality before harvesting and eventually production. As such, in this study, we collected representative Oolong tea samples from 15 regions in 8 countries. Quantitative description analysis (QDA) and a flavor wheel were used to analyze their sensory characteristics. Chemometrics was used to screen the phytochemical components that significantly contribute to the taste of Oolong tea. We preliminarily obtained 35 sensory characteristic descriptors and constructed a flavor wheel for Oolong tea. We found that Oolong tea in each region has unique sensory quality characteristics. The content of thirteen phytochemical components of Oolong tea in different regions widely varied, and the average coefficient of variation was 45.56%. Among of them, we found the largest difference in free amino acids. We identified the relationship between taste sub-attributes, and the thirteen phytochemical components was found through correlation analysis. Finally, we selected phytochemical components with significant effects on five taste sub-attributes that were selected from the thirteen detected phytochemical components. The construction of the Oolong tea flavor wheel can help realize the qualitative and quantitative sensory evaluation of Oolong tea from different origins and contribute to the quality identification and directional improvement of Oolong tea products.

The flavor differences in Oolong tea from different producing areas are caused by its complex differential compounds. In this study, representative samples of Oolong tea from four countries were collected, and their differential nonvolatile compounds were analyzed by a combination of widely targeted metabolomics, chemometrics, and quantitative taste evaluation. A total of 801 nonvolatile compounds were detected, which could be divided into 16 categories. We found that the difference in these compounds’ content among Oolong teas from three producing areas in China was the largest. There were 370 differential compounds related to the producing areas of Oolong tea, which were mainly distributed in 67 Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathways. In total, 81 differential nonvolatile compounds made important contributions to the taste differences in Oolong tea from different producing areas, among which the number of flavonoids was the largest. Finally, the characteristic compounds of Oolong tea in six producing areas were screened. This study comprehensively identifies the nonvolatile compounds of Oolong tea in different producing areas for the first time, which provides a basis for the analysis of flavor characteristics, quality directional control, and the identification and protection of geographical landmark agricultural products of Oolong tea from different producing areas.