水中Ca2+质量浓度对龙井茶冲泡茶汤滋味品质的影响

研究水中Ca~(2+)质量浓度对龙井茶冲泡茶汤滋味品质的影响。通过分析冲泡后茶汤的滋味品质、主要滋味物质的含量及Ca~(2+)对主要滋味物质呈味特性的影响,探讨Ca~(2+)对龙井茶冲泡茶汤滋味品质的影响。结果表明,随着水中Ca~(2+)质量浓度的增加,茶汤香气和滋味品质都显著下降,茶汤鲜爽度、醇度和苦味强度显著下降,而茶汤涩味强度显著增强;主要儿茶素、咖啡碱和氨基酸的浸出受Ca~(2+)影响较小,当Ca~(2+)质量浓度达到20 mg·L-1时才略有下降,不足以解释冲泡茶汤滋味品质的变化;Ca~(2+)对主要滋味物质的呈味特性有明显影响,Ca~(2+)可增强EGCG、咖啡碱和茶氨酸的涩味,降低EGCG和咖啡碱的苦味、茶氨酸的甜味和鲜味。本研究表明Ca~(2+)对龙井茶滋味物质浸出的影响相对较小,主要通过影响茶汤中滋味物质的呈味特性来改变茶汤整体滋味品质。

Effect of water Ca2+ concentration on taste quality of Longjing tea infusion

The effect of water Ca²⁺ concentration on taste quality of Longjing tea infusion was investigated. The taste quality and the concentration of the taste components of Longjing tea infusion and taste characteristics of main taste substances affected by Ca²⁺ were analyzed. The results showed that, with an increase of Ca²⁺ in water, the aroma and taste quality decreased and the intensity of umami, mellow and bitterness significantly also decreased, while the intensity of astringency significantly increased. However, the extraction of catechins, caffeine and amino acids from Longjing tea leaves was slightly affected. The concentrations of the main taste substances slightly decreased when the water Ca²⁺ reached to 20 mg·L^-1 the level at which the change of taste quality cannot be explained. The taste characteristic of the main taste substances was significantly affected. The intensity of astringency of EGCG, caffeine and theanine was significantly enhanced, while the intensity of bitterness of EGCG and caffeine and the intensities of sweetness and umami of theanine decreased. This study indicated that the extraction of taste substances was slightly affected by Ca²⁺ and the taste quality of tea infusion was affected by changing the taste characteristic of the taste substances.