Manufacturing process differences give Keemun black teas their distinctive aromas

Yujie Xu; Yaqin Liu; Jihong Yang; Hui Wang; Hanchen Zhou; Pandeng Lei

doi:10.1016/j.fochx.2023.100865

Manufacturing process differences give Keemun black teas their distinctive aromas

Food Chem X. 2023 Sep 9:19:100865. doi: 10.1016/j.fochx.2023.100865. eCollection 2023 Oct 30.

Authors

Yujie Xu¹, Yaqin Liu¹, Jihong Yang¹, Hui Wang¹, Hanchen Zhou¹, Pandeng Lei¹

Affiliation

¹ Tea Research Institute, Anhui Academy of Agricultural Sciences, Huangshan 245000, China.

Abstract

Traditional Keemun black tea is also known as Congou black tea (CF). Over the last three decades, three other types of Keemun black tea (Jinzhen, JZ; Maofeng, MF; Xiangluo, XL) made by different processing have been introduced into the tea market. Total CF volatile concentrations ranged from 1666.3 to 2185.7 μg/L, followed by XL (1193.5-1916.1 μg/L), JZ (1058.9-1811.0 μg/L), and MF (987.5-1518.0 μg/L) tea infusions. A total of 79 volatiles in tea infusions was identified by two methods, among which fourteen with OAVs > 1 were identified and OAVs proportion of volatiles with flowery, fruity, or sweet notes to those with other notes differed in four Keemun black teas (CF = 6.58:1, MF = 5.16:1, JZ = 4.04:1, XL = 5.11:1). Phenylethyl alcohol oxidation resulted in phenylacetaldehyde formation which is the characteristic odorant in Keemun black tea. We clearly show that changes in tea processing gives the distinctive aroma to different Keemun black teas.

Keywords: Aroma intensity; Keemun black tea; Odor activity value; Processing; Volatile compounds.