Enhancement of flavor components of oolong tea and dark tea based on graphene heating film

Reheating is crucial for improving tea quality, and graphene heating film provides a stable, uniform heating surface. This study used graphene heating film to heat oolong and dark tea at medium (M, 65 °C) and high (H, 75 °C) temperatures for 10, 20, and 30 min to assess the impact on flavor compounds. The results showed that the optimal parameters are as follows: the content of ester catechins decreased, the content of non-ester catechins increased, and the concentrations of woody and fruity compounds (Cedrol, Limonene, trans-Isoeugenol, Indole) significantly increased at M10 or H10 in oolong tea. The ester catechin content decreased at H20, the non-ester catechin content increased at M20, and the concentration of Floral compounds (trans-β-ionone) increased at H30 in dark tea. This study explores the potential of graphene heating film in tea processing, offering a theoretical basis for new technology in tea flavor enhancement.