冲泡用水中Mg^2+对红茶茶汤滋味品质的影响及机制  

Impact and Mechanism of Mg^2+in Brewing Water on the Taste Quality of Black Tea Infusions

作　　者：刘艳艳 许勇泉[2] 陈建新[2] 汪芳[2] 陈根生[2] 尹军峰[2] 刘政权[1] LIU Yanyan;XU Yongquan;CHEN Jianxin;WANG Fang;CHEN Gensheng;YIN Junfeng;LIU Zhengquan(College of Tea and Food Technology,Anhui Agricultural University,Hefei 230036,China;Tea Research Institute Chinese Academy of Agricultural Sciences,State Engineering Research Center for Tea Processing,Hangzhou 310008,China)

机构地区：[1]安徽农业大学茶与食品科技学院,安徽合肥230036 [2]中国农业科学院茶叶研究所,国家茶产业工程技术研究中心,浙江杭州310008

出　　处：《食品科学》2020年第18期14-20,共7页Food Science

基　　金：国家自然科学基金面上项目(31671861);浙江省重点研发计划项目(2019C02072)。

摘　　要：研究水中Mg^2+对红茶茶汤滋味品质与理化成分浸出的影响,通过Mg^2+与主要味感物间的滋味互作效应分析探索其中的机制。研究表明,高质量浓度Mg^2+的水(≥16 mg/L)冲泡的茶汤品质明显下降,并随着水中Mg^2+质量浓度的提高,冲泡茶汤的鲜味、甜味、苦味下降,而涩味明显增强;茶汤中茶多酚、儿茶素、氨基酸、咖啡碱以及Al^3+、B^3+、K^+、Na^+、S^6+等主要成分浸出含量呈下降趋势,部分解释了茶汤苦味、鲜味下降的成因。进一步研究发现,Mg^2+可增强表没食子儿茶素没食子酸酯(epiggallocatechin gallate,EGCG)、咖啡碱和谷氨酸钠溶液的涩味,削弱EGCG和咖啡碱溶液的苦味、谷氨酸钠溶液的鲜味和蔗糖溶液的甜味,具有明显的滋味互作效应;随着Mg^2+质量浓度的增加,EGCG-蛋白质混合液形成的浊度显著上升,验证了Mg^2+可以增加红茶茶汤涩味强度的结论。本研究结果建议日常冲泡红茶应选用Mg^2+质量浓度较低的水(≤4 mg/L)。The effect of Mg^2+in brewing water on the taste quality and chemical ingredients of black tea infusion was investigated.The underlying mechanism was inferred from the interaction among the main taste substances of black tea infusion in the presence of Mg^2+.The results showed that the quality of tea infusion with high Mg^2+concentration(≥16 mg/L)was fairly poor.As the concentration of Mg^2+increased,the umami taste,sweetness and bitterness of tea infusion decreased,while the astringency significantly increased.The contents of tea polyphenols,catechins,amino acids and caffeine,as well as Al3+,B3+,K+,Na+and S6+in tea infusion showed a downward trend,partially accounting for the decrease in the bitterness and umami taste of tea infusion.Furthermore,we found that Mg^2+not only enhanced the astringency of epiggallocatechin gallate(EGCG),caffeine and sodium glutamate solutions,but also weakened the bitterness of EGCG and caffeine solutions,the umami taste of sodium glutamate solution and the sweetness of sucrose solution,indicating a significant effect of Mg^2+on the taste components.With increasing concentration of Mg^2+in brewing water,the turbidity of EGCG-protein mixture solution increased significantly,which confirmed the conclusion that Mg^2+can strengthen the astringency intensity of tea infusion.The results of this study suggested that water that contain relatively low concentration of Mg^2+(≤4 mg/L)be used for brewing of black tea in daily life.

关 键 词：MG^2+ 红茶茶汤 滋味品质 滋味成分 

分 类 号：TS272.2[农业科学—茶叶生产加工]