Kaneko Shu, Kumazawa Kenji, Masuda Hideki, Henze Andrea, Hofmann Thomas
Material R & D Laboratory, Ogawa & Co. Ltd., Chidori 15-7, 279-0032, Urayasu, Chiba, Japan.
J Agric Food Chem. 2006 Apr 5;54(7):2688-94. doi: 10.1021/jf0525232.
Aimed at defining the key drivers for the quality-determining umami taste of a high-grade powdered green tea, called mat-cha, a bioactivity-guided fractionation using solvent extraction, solvent precipitation, preparative chromatographic separations, and human psychophysical experiments was applied on freshly prepared mat-cha. Liquid chromatography-tandem mass spectrometry and one-/two-dimensional nuclear magnetic resonance studies on isolated fractions led to the identification of l-theanine, succinic acid, 3,4,5-trihydroxybenzoic acid (gallic acid), and (1R,2R,3R,5S)-5-carboxy-2,3,5-trihydroxycyclohexyl-3,4,5-trihydroxybenzoate (theogallin) as umami-enhancing compounds in the green tea beverage, and it can be shown by sensory studies that these compounds are able to raise the umami intensity of sodium l-glutamate proportionally.
为了确定高品质抹茶（一种高级绿茶粉）中决定鲜味品质的关键驱动因素，我们对新鲜制备的抹茶进行了生物活性导向的分级分离，采用了溶剂萃取、溶剂沉淀、制备色谱分离和人体心理物理学实验。对分离出的组分进行液相色谱-串联质谱分析以及一维/二维核磁共振研究，结果鉴定出L-茶氨酸、琥珀酸、3,4,5-三羟基苯甲酸（没食子酸）和(1R,2R,3R,5S)-5-羧基-2,3,5-三羟基环己基-3,4,5-三羟基苯甲酸酯（茶黄素）是绿茶饮料中增强鲜味的化合物，感官研究表明这些化合物能够按比例提高L-谷氨酸钠的鲜味强度。
