Investigation of the effects of different water sources on the brew quality and bioactive properties of black tea.

In this study, the physicochemical, biological, and sensory properties of black tea infusions prepared with different spring waters were comprehensively evaluated. Significant differences were identified among the spring waters in key chemical parameters such as pH, TDS (total dissolved solids), and EC (electrical conductivity). These differences were found to directly influence the characteristics of the tea infusions. The tea brewing process led to changes in pH values and marked increases in TDS and EC levels. This phenomenon was attributed to the buffering effect of tea and the transfer of phenolic compounds and minerals into the infusion. Although no statistically significant differences were observed in total phenolic content among the water sources, antioxidant activity varied significantly depending on the water used. This finding indicates that the chemical properties of water affect the transfer of phenolic compounds into the infusion and influence antioxidant activity. Statistically significant differences in antifungal activity were found among teas prepared with different water sources. Notably, tea brewed with Perşembe water exhibited the highest inhibition zone. Spectrophotometric analyses revealed that the water sources significantly affected the color of the tea infusions. Overall, the findings demonstrate that the physicochemical composition of the water used in brewing has a meaningful impact on the chemical, biological, and sensory properties of black tea. This highlights the importance of water quality as a key factor in controlling the functional properties of tea.