The effects of some aromatic plants added to black tea in the infusion stage on aroma and aroma active compounds, antioxidant capacity and antibacterial activity of black tea

In this study, black tea produced from two leaves and a bud were used as black tea. It is infused for 10 minutes with different herbs added to the tea. Clove, dried mint, rose and green tea determined by trials were added to black tea and the mineral content (Ca,K,Mg,Fe), aroma, aroma-active compounds, total phenolic content, antioxidant capacity, antibacterial effect and color properties of the teas were compared with the control tea sample. Aroma extractions were made by liquid-liquid extraction method. GC-MS Olfactometry was used to determine aroma and aroma-active compounds. The richest example in terms of aroma was black tea with mint. The aromatic plants added to black tea enriched the amount of mineral content, aroma and aroma-active compounds of the teas. In terms of antibacterial activity the tea samples did not exhibit an antibacterial activities against S. aureus ATCC 29213; but all tea samples exhibited antimicrobial activities against E.coli ATCC 25922. Among the samples, black tea with rose provided better activity for this microorganism than the others. On the other hand as a result of the sensory analysis, the most liked sample was black tea with rose.