Metabolome technology reveals the material basis for the formation of characteristic flavors in four types of purple teas

Purple-shoot tea trees are valuable resources with unique traits, research potential, and health benefits, but studies on the distinct quality and flavor of their derived varieties remain limited. Here, we used the novel cultivar Zifuxing No.1 (ZFX1) to analyze volatile/non-volatile compounds in its fresh leaves (FL) and four processed products: black tea (BT), green tea (GT), white tea (WT), and oolong tea (OT).LC-MS/MS and HS-SPME-GC–MS identified 387 non-volatile and 987 volatile metabolites. Tea processing significantly altered flavonoids, amino acids/derivatives, nucleotides/derivatives, and lipids, highlighting its profound impact on metabolic profiles and providing insights into the biochemical transformations shaping purple tea characteristics. Based on rOAV≥1, 11 core volatile differential metabolites (including β-damascenone, 1-octen-3-one, methyl hexanoate, and γ-caprolactone) were identified, which positively correlated with fruity, floral, and sweet aromas and collectively shaped ZFX1 tea's distinctive aromatic profile. This study clarifies flavor and metabolic variations among ZFX1 tea types, providing a theoretical basis for understanding purple-shoot tea flavor attributes and supporting rational development of ZFX1 resources. • Systematically identify and evaluate the flavor characteristics of four types of purple tea made from the same fresh tea leaf raw materials. • As the fermentation degree increases, the aroma and flavor of purple tea change from green floral fragrance (similar to that of green tea and white tea) to sweet floral fragrance (similar to that of oolong tea and black tea). • Flavonoids, phenolic acids, amino acids and their derivatives, as well as lipids are the main non-volatile metabolites distinguishing the four types of purple tea. • Eleven key volatile metabolites positively correlated with floral, fruity, and sweet aromas jointly endow four types of purple tea with unique aroma characteristics.