抹茶茶汤感官理化特性、多酚组成及抗氧化活性研究

研究了两种市售抹茶茶汤理化指标、多酚化学组成及抗氧化活性,并进行感官审评。结果表明:随着冲泡次数的增加,抹茶汤的pH值增加,可滴定酸含量降低,色泽明亮度增加但黄蓝度降低。同时,一泡茶汤较二泡、三泡茶汤具有最优的色香味感官品质。此外,两种抹茶茶汤的总多酚含量、多酚组成及体外抗氧化活性无显著差异,但均随冲泡次数递减;UPLC所分析茶汤中的9种化学物质中含量相对较高的成分依次为表没食子儿茶素没食子酸酯、咖啡因和表没食子儿茶素。

Study on physicochemical and sensory properties, polyphenolic composition and antioxidant capacity of matcha tea infusion

The physicochemical and sensory properties, polyphenolic composition, and antioxidant capacity of two kinds of matcha tea infusion were investigated in the present study. The results showed that the pH increased slightly, and the titratable acid content decreased dramatically from the first to the third brew. Meanwhile, the infusions of the first brew had optimal color and scent sensory quality compared with those of the second and third brews. Furthermore, the total polyphenol content, polyphenolic composition, and antioxidant capacity of tea infusions showed no significant difference between the two kinds of matcha tea, but all decreased to some degrees during the three successive extractions. Chemical profiling by UPLC further confirmed nine phytochemicals in these infusions, in which epigallocatechin gallate, caffeine, and epigallocatechin predominated, respectively.