Identification of key odorants in Turkish black tea beverage and aroma changes by adding aromatic plants

Tea, produced from the leaves of Camellia sinensis, is one of the most widely consumed beverages worldwide. Some consumers infuse these teas by blending with different medicinal and aromatic plants for both taste and health benefits. This study examines the impact of adding four aromatic plants (dried cloves (C), mint (M), rose petals (R), and green tea (GT)) to black tea (BT) on its aroma profile, aroma-active compounds (AACs), and bioactive properties. Sensory analysis and gas chromatography-mass spectrometry (GC-MS) were used to evaluate the aroma profile, while total phenolic content (TPC) and antioxidant activity were measured to assess bioactive properties. The black tea (BT) sample with added green tea (BT+GT) had the highest total phenolic substance (TPC) and antioxidant activity (AA) followed by the BT+R, BT+C, BT+M and BT samples, respectively. The clove, mint, rose and green tea added to the BT increased its aroma potential significantly. The types and numbers of the AACs responsible for the unique odour of the tea samples showed significant differences. It was found that the characteristic aroma components found in the added aromatic plants were transferred to the BT. Sensory evaluation indicated that the aromatic plant additions enhanced the overall sensory characteristics of BT, with the BT+rose (BT+R) sample receiving the highest preference scores.