Effect of the type of brewing water on the chemical composition, sensory quality and antioxidant capacity of Chinese teas

- Sensory quality of tea infusions was influenced by the brewing water.
- Antioxidant capacity of tea infusions was influenced by the brewing water.
- High pH of brewing water influences the stability of catechins in tea infusion.
- High conductivity decreases the extraction yield of catechins and caffeine.
- Reduce the pH of brewing water partly improve the taste quality of tea infusion.

The physicochemical characteristics, sensory quality, and antioxidant activity of tea infusions prepared with purified water (PW), mineral water (MW), mountain spring water (MSW), and tap water (TW) from Hangzhou were investigated. The results showed that the taste quality, catechin concentration, and antioxidant capacity of green, oolong, and black tea infusions prepared using MW and TW were significantly lower than those prepared using PW. Extraction of catechins and caffeine was reduced with high-conductivity water, while high pH influenced the stability of catechins. PW and MSW were more suitable for brewing green and oolong teas, while MSW, with low pH and moderate ion concentration, was the most suitable water for brewing black tea. Lowering the pH of mineral water partially improved the taste quality and increased the concentration of catechins in the infusions. These results aid selection of the most appropriate water for brewing Chinese teas.