The Influence of Water Composition on Flavor and Nutrient Extraction in Green and Black Tea

摘要

Tea is made from the processed leaves of the Camellia sinensis plant, which is a tropical and subtropical evergreen plant native to Asia. Behind water, tea is the most consumed beverage in the world. Factors that affect tea brewing include brewing temperature, vessel, and time, water-to-leaf ratio, and, in some reports, the composition of the water used. In this project, we tested if the water used to brew tea was sufficient to influence perceived flavor to the everyday tea drinker. Black and green tea were brewed with bottled, tap, and deionized water, with brewing temperature, vessel, time, and the water-to-leaf ratio matched. The samples were analyzed with a human consumer sensory panel, as well as instrumentally for color, turbidity, and Epigallocatechin Gallate (EGCG) content. Results showed that the type of water used to brew tea drastically affected sensory properties of green tea (and mildly also for black tea), which was likely driven by a much greater degree of extraction of bitter catechins in teas brewed with more purified bottled or deionized water. For the everyday tea drinker who drinks green tea for health, the capability to double the EGCG content in tea by simply brewing with bottled or deionized water represents a clear advantage. Conversely, those drinking tea for flavor may benefit from instead brewing tea with tap water.