Tea Research Institute Chinese Academy of Agricultural Sciences, Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, 9 South Meiling Road, Hangzhou 310008, China; College of Tea Science, Yunnan Agriculture University, Kunming 650201, China.
Tea Research Institute Chinese Academy of Agricultural Sciences, Key Laboratory of Tea Biology and Resources Utilization, Ministry of Agriculture, 9 South Meiling Road, Hangzhou 310008, China.
Food Chem. 2023 Sep 1;419:136079. doi: 10.1016/j.foodchem.2023.136079. Epub 2023 Apr 6.
The sensory quality of tea is influenced by water quality, with natural spring water (NSW) gaining much attention for its natural and healthy qualities. The effects of NSW on the sensory attributes, physicochemical composition, and antioxidant capacity of Chinese tea were investigated. Tea brewed with pure water was the most resistant to oxidation and darkening. NSW with low total dissolved solids (TDS) was most suitable for brewing unfermented or mildly fermented teas, improving their sensory quality. The simulated green tea infusion system was used to investigate further the dramatic darkening of tea infusions in NSW. Exposure of infusions to air promoted the degradation, epimerization, and oxidative polymerization of catechins, and further formed theabrownins which darkened the tea infusions. These findings enabled tea consumers to choose the most suitable NSW for brewing Chinese teas and illustrated the darkening mechanism of tea infusion in high pH/TDS water.
水质会影响茶的感官品质，天然泉水（NSW）因其天然健康的品质而备受关注。研究了 NSW 对中国茶感官属性、理化成分和抗氧化能力的影响。用纯净水冲泡的茶最能抵抗氧化和变暗。总溶解固体（TDS）低的 NSW 最适合冲泡未发酵或轻度发酵的茶，可改善其感官品质。采用模拟绿茶浸提体系进一步研究了 NSW 中茶浸提液的急剧变暗现象。暴露于空气中会促进儿茶素的降解、差向异构化和氧化聚合，并进一步形成茶褐色素，使茶浸提液变暗。这些发现使茶消费者能够选择最适合冲泡中国茶的 NSW，并说明了高 pH/TDS 水中茶浸提液变暗的机制。
