# Chemical Drivers of Flavor Variation Across Cultivars and Grades of Fujian White Tea Revealed by Integrated Volatile and Non-Volatile Metabolomics

## TL;DR

This study identifies chemical markers that distinguish the flavor and quality of different grades and cultivars of Fujian white tea.

## Contribution

The research reveals specific volatile and non-volatile metabolites linked to grade and cultivar differences in white tea.

## Key findings

- Non-volatile markers like catechins and amino acids decrease with lower grades, while flavonol glycosides and gallic acid increase.
- Higher-grade white teas are characterized by floral aromas, while lower-grade teas have more herbal notes.
- Cultivars differ in aroma profiles, with Fuding Dabai and Fuding Dahao showing floral-fruity aromas and others showing herbal and aged aromas.

## Abstract

Grade and cultivar are the important factors influencing white tea quality, but their relative metabolic contributions are not fully understood. Twelve white tea samples representing four major Fujian cultivars across three grades were analyzed using UHPLC–MS-based non-volatile metabolomics, HS-SPME–GC–MS volatile profiling, and sensory correlation analysis. In total, 47 non-volatile and 21 volatile markers were associated with grade differences, while 44 non-volatile and 26 volatile markers were linked to cultivar differences. Catechins and amino acids declined as grade decreased, whereas flavonol glycosides and gallic acid increased, accompanied by stronger astringency and reduced umami and sweetness. Aroma profiles showed a similar trend, with higher-grade teas dominated by floral notes and lower-grade teas exhibiting more herbal characteristics. Dimeric catechins, oxylipins, and aroma glycosides varied among cultivars. Volatile profiles separated the cultivars into two aroma groups: Fuding Dabai and Fuding Dahao showed more floral–fruity aromas, whereas Fuan Dabai and Zhenghe Dabai exhibited stronger herbal and aged aromas. Odor activity value analysis showed that linalool, geraniol, and (E,Z)-3,6-nonadien-1-ol were among the most abundant aroma-active compounds across white tea samples. These results provide chemical evidence for distinguishing white tea by grade and cultivar, with potential relevance to quality evaluation.