Abstract: To ascertain differences of quality and mineral elements among different grades of Wuyi Shuixian tea, contents of tea polyphenols, theanine, soluble sugar, free amino acid, water extract, caffeine, total flavonoids, total catechins and 5 catechin compositions were determined, and mineral element contents were measured. The correlations between the evaluated grades and the contents of effective components were analyzed. The results showed that the contents of total flavonoids and water extract in high grades of Wuyi Shuixian were higher. The contents of Epigallocatechin gallate (EGCG) and Epicatechin gallate (ECG) were significantly difference between SA and other grades. Except Ca, Mg, Mn, Al and B, there was no significant difference on the contents of mineral elements among different grades of Wuyi Shuixian. The results of heat map analysis further showed that theanine, ECG and epigallocatechin (EGC) were more accumulated in SB, SC and SD grades, while total flavonoids, Ca, Mn, K, P and N were more accumulated in SA grade. The principal coordinate analysis showed that the contribution  rates of the quality index and mineral elements on the difference of the grades in Wuyi Shuixian were 27.98% and 30.89%, respectively, which could better classified the grade of Wuyi Shuixian. These results provided scientific basis for the grade identification of Wuyi Shuixian.

Key words: tea plant, quality, grade, mineral elements

摘要： 为探明不同等级武夷水仙茶之间的差异，测定了茶多酚、茶氨酸、可溶性糖、游离氨基酸、水浸出物、咖啡碱、总黄酮、总儿茶素、5种儿茶素组分和14种矿质元素含量，分析了审评得分（等级）与茶叶内含物质含量和矿质元素含量之间的相关性。结果表明：等级高的武夷水仙总黄酮和水浸出物含量相对较高，儿茶素组分中表没食子儿茶素没食子酸酯（epigallocatechin gallate，EGCG）、表儿茶素没食子酸酯（epicatechin gallate，ECG）含量在SA级与其他等级武夷水仙之间差异显著。14种矿物元素中，除Ca、Mg、Mn、Al和B外，不同等级武夷水仙大多数矿质元素含量之间没有差异。热图分析结果进一步表明，武夷水仙SB、SC、SD 3个等级主要在茶氨酸、ECG和表没食子儿茶素（epigallocatechin，EGC）上积累，总黄酮在SA级茶中积累明显；SA级武夷水仙主要在Ca、Mn、K、P和N上有积累。主坐标分析表明品质指标对武夷水仙茶等级间差异的解释率为2798%；14种矿质元素对武夷水仙等级间的差异性解释率达到了30.89%，较好地区分了不同等级的武夷水仙。

关键词: 茶树, 品质, 等级, 矿质元素