Effects of Repeated Brewing on Dissolution of Fujian White Tea Components
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摘要:
目的 探讨白茶不同泡次茶汤内含物溶释的特点和规律,为白茶工艺、品质改进及科学饮茶提供理论依据。 方法 选择2个茶树品种不同茶叶等级共4个茶样,按白茶审评方法冲泡茶汤,测定3泡次内含物的溶出量、溶出率。 结果 (1)4个茶样各内含物3泡总溶出量均值为多酚类(9.56 g·hg−1)>儿茶素(4.78 g·hg−1)>可溶性糖(4.26 g·hg−1)>茶褐素(3.98 g·hg−1)>茶红素(3.59 g·hg−1)>咖啡碱(3.26 g·hg−1)>氨基酸(2.38 g·hg−1)>黄酮(0.45 g·hg−1)>茶黄素(0.12 g·hg−1);3泡总溶出率均值为咖啡碱(78.95%)>黄酮(70.71%)>氨基酸(66.69%)>茶褐素(63.98%)>茶红素(61.97%)>多酚类(55.77%)>可溶性糖(53.27%)>儿茶素(40.42%)>茶黄素(31.34%),表没食子儿茶素没食子酸酯(EGCG)、茶氨酸(The)分别为43.31%、63.23%;(2)第1至第3泡溶出率,除茶红素、可溶性糖外,其余内含物呈下降趋势,其中咖啡碱、氨基酸、黄酮第1泡溶出率最高,其在4个茶样第1泡的溶出率均值分别为37.13%、31.54%、29.73%,且3泡总溶出率也高;(3)同一茶样3次冲泡中,水浸出物、多酚类、咖啡碱、黄酮、茶红素溶出量的增减程度均达到显著差异(P<0.05)水平,而咖啡碱、氨基酸溶出率逐次下降明显,降幅达9%以上;(4)不同茶样相同泡次之间,内含物溶出率总体上未表现出茶叶品种和等级之间的规律性差异。 结论 除茶红素、可溶性糖外,其余内含物溶出量、溶出率为第1泡>第2泡>第3泡,但内含物之间的溶释效率存在明显差异,咖啡碱、氨基酸、黄酮等溶出较快,而多酚类、儿茶素及EGCG、The等高含量内含物或组分并未充分溶释,尤其是儿茶素、EGCG和表儿茶素没食子酸酯(ECG),其3泡总溶出率均低于50%。 Abstract:Objective The dissolved components in the brews of Fujian white teas were investigated. Method 4 local white tea products of 2 cultivar varieties and 2 quality grades were brewed by the standard procedures for sensory evaluation on white tea. The components in the 3 series of brewed teas were analyzed. Result (1) After 3 series of brewing the average total dissolved amounts of the components were 9.56 g·hg−1 for polyphenol, 4.78 g·hg−1 for catechin, 4.26 g·hg−1 for soluble sugar, 3.98 g·hg−1 for theabrownine, 3.59 g·hg−1 for thearubigin, 3.26 g·hg−1 for caffeine, 2.38 g·hg−1 for amino acid, 0.45 g·hg−1 for flavone, and 0.12 g·hg−1 for theaflavin, the average total dissolved rates of the components were 78.95% for caffeine, 70.71% for flavone, 66.69% for amino acid, 63.98% for theabrownine, 63.23% for theanine, 61.97% for thearubigin, 55.77% for polyphenol, 53.27% for soluble sugar, 43.31% for EGCG, 40.42% for catechin, and 31.34% for theaflavin. (2) Except for thearubigin and soluble sugar, all the other components decreased in their dissolved amounts and rates from the 1st to the 3rd brewing, among which caffeine,amino acid and flavone showed the highest average dissolved rates of 37.13%,31.54%,29.73% respectively in the 1st brewing. (3) Polyphenol, caffeine, flavone or thearubigin differed significantly (P<0.05) between its dissolved amounts of 3 series of brewing of the same sample.The dissolved rates of caffeine and amino acid decreased significantly by more than 9% in one more brewing, while the dissolved rates of the components generally did not show regular differences between the varieties and the grades. Conclusion The dissolved amounts and rates of the components tested, except for thearubigin and soluble sugar, declined from the 1st to the 3rd brewing. In 3 consecutive brewing, due to differences in solubility, caffeine, flavone and amino acid rapidly leached, polyphenol and theanine partly dissolved, and less than 50% of catechin, EGCG and ECG in the dry leaf dissolved in 3 brewings. -
Key words:
- White tea /
- biochemicals /
- repeated brewing /
- dissolved amounts /
- dissolved rates
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表 1 供试茶样及编号
Table 1. Tea samples and codes
茶样编号
Tea No产地
Place of origin茶树品种
Cultivar品名、等级
Product name & gradeFD1 福建 政和 Zhenghe county, Fujian province 福鼎大白茶 Fuding big & white leaf 白牡丹一级 White peony of 1st grade FD3 福建 政和 Zhenghe county, Fujian province 福鼎大白茶 Fuding big & white leaf 白牡丹三级 White peony of 3rd grade ZD1 福建 政和 Zhenghe county, Fujian province 政和大白茶 Zhenghe big & white leaf 白牡丹一级 White peony of 1st grade ZD3 福建 政和 Zhenghe county, Fujian province 政和大白茶 Zhenghe big & white leaf 白牡丹三级 White peony of 3rd grade 表 2 不同泡次对水浸出物溶出量、溶出率的影响
Table 2. Effects of repeated brewing on dissolved amount and rate of water extract
茶样编号
Tea No总量
Total amount/(g·hg−1)溶出量 Amount dissolved/(g·hg−1) 溶出率 Ratio to total amount/% 第1泡
1st brew第2泡
2nd brew第3泡
3rd brew合计
Total第1泡
1st brew第2泡
2nd brew第3泡
3rd brew合计
TotalFD1 47.47±1.26 13.53±0.17 a 8.68±0.40 b 5.50±0.06 c 27.71 28.50 18.29 11.59 58.37 FD3 47.70±1.34 12.37±0.27 a 8.39±0.21 b 5.34±0.13 c 26.10 25.93 17.59 11.19 54.72 ZD1 46.18±0.36 12.67±0.55 a 8.58±0.18 b 6.20±0.60 c 27.45 27.44 18.58 13.43 59.44 ZD3 47.11±0.31 12.23±0.70 a 9.02±0.11 b 6.04±0.49 c 27.29 25.96 19.15 12.82 57.93 平均值 Mean values 47.12 12.70 8.67 5.77 27.14 26.96 18.40 12.26 57.62 注:表中溶出量数据为平均值±标准偏差,同行数据之间小写字母(括号外)不同表示泡次之间差异达到显著水平(P<0.05);同列数据之间小写字母(括号内)不同表示茶样之间差异达到显著水平(P<0.05);未标注则表示同行或同列数据之间无显著差异。表3、表5~7、表9~11同。
Note: Data are mean±standard deviation; those with different lowercase letters on same row indicate significant difference at P<0.05; those with different lowercase letters on same column (in parentheses) indicate significant difference at P<0.05; those without marked letter indicate no significant difference. Same for Table 3, 5-7, and 9-11.表 3 不同泡次对可溶性糖溶出量、溶出率的影响
Table 3. Effects of repeated brewing on dissolved amount and rate of soluble sugar
茶样编号
Tea No总量
Total amount/(g·hg−1)溶出量 Amount dissolved/(g·hg−1) 溶出率 Ratio to total amount/% 第1泡
1st brew第2泡
2nd brew第3泡
3rd brew合计
Total第1泡
1st brew第2泡
2nd brew第3泡
3rd brew合计
TotalFD1 7.89±0.01 1.42±0.00 1.42±0.00 1.41±0.00 4.25 18.00 18.00 17.87 53.87 FD3 8.07±0.01 1.42±0.00 1.42±0.00 1.42±0.00 4.26 17.60 17.60 17.60 52.79 ZD1 7.98±0.02 1.42±0.00 1.42±0.00 1.42±0.00 4.26 17.79 17.79 17.79 53.38 ZD3 8.02±0.01 1.42±0.00 1.42±0.00 1.41±0.00 4.25 17.71 17.71 17.58 52.99 平均值 Mean values 7.99 1.42 1.42 1.42 4.26 17.78 17.78 17.71 53.27 表 4 不同泡次对氨基酸溶出量、溶出率的影响
Table 4. Effects of repeated brewing on dissolved amount and rate of amino acid
茶样编号
Tea No总量
Total amount/(g·hg−1)溶出量 Amount dissolved/(g·hg−1) 溶出率 Ratio to total amount/% 第1泡
1st brew第2泡
2nd brew第3泡
3rd brew合计
Total第1泡
1st brew第2泡
2nd brew第3泡
3rd brew合计
TotalFD1 4.35 1.46 1.00 0.50 2.96 33.33 22.99 11.49 67.81 FD3 3.50 1.20 0.77 0.45 2.42 34.29 22.00 12.86 69.15 ZD1 3.50 1.06 0.80 0.45 2.31 30.29 22.86 12.86 66.00 ZD3 2.76 0.78 0.60 0.38 1.76 28.26 21.74 13.77 63.77 平均值 Mean values 3.53 1.13 0.79 0.46 2.38 31.54 22.40 12.75 66.69 表 5 不同泡次对咖啡碱溶出量、溶出率的影响
Table 5. Effects of repeated brewing on dissolved amount and rate of caffeine
茶样编号
Tea No总量
Total amount/(g·hg−1)溶出量 Amount dissolved/(g·hg−1) 溶出率 Ratio to total amount/% 第1泡
1st brew第2泡
2nd brew第3泡
3rd brew合计
Total第1泡
1st brew第2泡
2nd brew第3泡
3rd brew合计
TotalFD1 4.54±0.20 1.67±0.11 a(a) 1.38±0.04 b(a) 0.65±0.04 c(a) 3.70 36.78 30.4 14.32 81.50 FD3 4.08±0.09 1.66±0.03 a(a) 1.15±0.11 b(b) 0.61±0.10 c(a) 3.42 40.69 28.19 14.95 83.82 ZD1 4.09±0.08 1.59±0.07 a(a) 1.10±0.03 b(bc) 0.57±0.02 c(ab) 3.26 38.88 26.89 13.94 79.71 ZD3 3.76±0.11 1.21±0.06 a(b) 0.98±0.02 b(c) 0.47±0.06 c(b) 2.66 32.18 26.06 12.50 70.74 平均值 Mean values 4.12 1.53 1.15 0.58 3.26 37.13 27.89 13.93 78.95 表 6 不同泡次对多酚类溶出量、溶出率的影响
Table 6. Effects of repeated brewing on dissolved amount and rate of polyphenol
茶样编号
Tea No总量
Total amount/(g·hg−1)溶出量 Amount dissolved/(g·hg−1) 溶出率 Ratio to total amount/% 第1泡
1st brew第2泡
2nd brew第3泡
3rd brew合计
Total第1泡
1st brew第2泡
2nd brew第3泡
3rd brew合计
TotalFD1 17.11±1.90 4.48±0.36 a(a) 3.31±0.37 b 2.24±0.31 c 10.03 26.18 19.35 13.09 58.62 FD3 17.46±1.80 3.73±0.34 a(b) 3.05±0.21 b 2.05±0.14 c 8.83 21.36 17.47 11.74 50.57 ZD1 16.59±0.68 3.75±0.32 b(b) 3.09±0.17 c 2.41±0.21 d 9.25 22.60 18.63 14.53 55.76 ZD3 17.39±2.11 4.48±0.36 a(a) 3.30±0.37 c 2.33±0.31 d 10.11 25.76 18.98 13.40 58.14 平均值 Mean values 17.14 4.11 3.19 2.26 9.56 23.98 18.6 13.19 55.77 表 7 不同泡次对黄酮溶出量、溶出率的影响
Table 7. Effects of repeated brewing on dissolved amount and rate of flavone
茶样编号
Tea No总量
Total amount/(g·hg−1)溶出量 Amount dissolved/(g·hg−1) 溶出率 Ratio to total amount/% 第1泡
1st brew第2泡
2nd brew第3泡
3rd brew合计
Total第1泡
1st brew第2泡
2nd brew第3泡
3rd brew合计
TotalFD1 0.59±0.05 0.22±0.01 a(a) 0.16±0.01 b(a) 0.12±0.00 c(a) 0.5 37.29 27.12 20.34 84.75 FD3 0.73±0.06 0.20±0.01 a(b) 0.17±0.00 b(a) 0.13±0.00 c(a) 0.49 27.40 23.29 17.81 67.12 ZD1 0.62±0.06 0.20±0.01 a(b) 0.15±0.01 b(a) 0.11±0.00 c(a) 0.46 33.33 25.00 18.33 76.67 ZD3 0.67±0.04 0.14±0.00 a(c) 0.11±0.01 b(b) 0.09±0.00 c(b) 0.34 20.90 16.42 13.43 50.75 平均值 Mean values 0.65 0.19 0.15 0.11 0.45 29.73 22.96 17.48 70.71 表 8 不同泡次对儿茶素溶出量、溶出率的影响
Table 8. Effects of repeated brewing on dissolved amount and rate of catechin
茶样编号
Tea No总量
Total amount/(g·hg−1)溶出量 Amount dissolved/(g·hg−1) 溶出率 Ratio to total amount/% 第1泡
1st brew第2泡
2nd brew第3泡
3rd brew合计
Total第1泡
1st brew第2泡
2nd brew第3泡
3rd brew合计
TotalFD1 10.80 1.70 1.60 1.10 4.40 15.74 14.81 10.19 40.74 FD3 11.60 2.00 1.80 1.30 5.10 17.24 15.52 11.21 43.97 ZD1 11.40 2.00 1.50 1.10 4.80 17.54 13.16 9.65 40.35 ZD3 13.70 2.00 1.89 1.10 4.99 14.80 13.80 8.03 36.63 平均值 Mean values 11.88 1.93 1.70 1.15 4.78 16.33 14.32 9.77 40.42 表 9 不同泡次对茶红素溶出量、溶出率的影响
Table 9. Effects of repeated brewing on dissolved amount and rate of thearubigin
茶样编号
Tea No总量
Total amount/(g·hg−1)溶出量 Amount dissolved/(g·hg−1) 溶出率 Ratio to total amount/% 第1泡
1st brew第2泡
2nd brew第3泡
3rd brew合计
Total第1泡
1st brew第2泡
2nd brew第3泡
3rd brew合计
TotalFD1 5.70±0.16 0.79±0.24 a 0.94±0.16 b 1.79±0.03 c 3.52 13.79 16.52 31.32 61.63 FD3 5.99±0.09 0.81±0.01 a 0.96±0.03 b 1.83±0.02 c 3.60 13.59 16.02 30.60 60.22 ZD1 5.82±0.25 0.79±0.01 a 0.98±0.05 b 1.89±0.03 c 3.66 13.62 16.78 32.40 62.79 ZD3 5.62±0.18 0.79±0.00 a 0.95±0.01 b 1.81±0.02 c 3.55 14.08 16.95 32.19 63.21 平均值 Mean values 5.78 0.80 0.96 1.83 3.59 13.77 16.57 31.63 61.97 表 10 不同泡次对茶黄素溶出量、溶出率的影响
Table 10. Effects of repeated brewing on dissolved amount and rate of theaflavin
茶样编号
Tea No总量
Total amount/(g·hg−1)溶出量 Amount dissolved/(g·hg−1) 溶出率 Ratio to total amount/% 第1泡
1st brew第2泡
2nd brew第3泡
3rd brew合计
Total第1泡
1st brew第2泡
2nd brew第3泡
3rd brew合计
TotalFD1 0.36±0.00 0.04±0.00 a(a) 0.04±0.00 a(a) 0.03±0.00 b 0.11 10.55 10.58 8.29 29.42 FD3 0.38±0.00 0.04±0.00 a(a) 0.04±0.00 a(a) 0.03±0.00 b 0.11 11.53 10.03 8.04 29.60 ZD1 0.34±0.00 0.04±0.00 a(a) 0.03±0.00 b(b) 0.03±0.00 b 0.1 10.60 10.21 9.41 30.22 ZD3 0.35±0.00 0.06±0.00 a(b) 0.04±0.00 b(a) 0.03±0.00 c 0.13 17.18 10.71 8.25 36.14 平均值 Mean values 0.36 0.05 0.04 0.03 0.12 12.46 10.38 8.50 31.34 表 11 不同泡次对茶褐素溶出量、溶出率的影响
Table 11. Effects of repeated brewing on dissolved amount and rate of theabrownine
茶样编号
Tea No总量
Total amount/(g·hg−1)溶出量 Amount dissolved/(g·hg−1) 溶出率 Ratio to total amount/% 第1泡
1st brew第2泡
2nd brew第3泡
3rd brew合计
Total第1泡
1st brew第2泡
2nd brew第3泡
3rd brew合计
TotalFD1 6.13±0.07 1.37±0.11 a 1.42±0.09 a 1.13±0.05 b 3.92 22.39 23.2 18.39 63.98 FD3 6.38±0.25 1.44±0.14 a 1.47±0.06 a 1.12±0.06 b 4.03 22.57 23.08 17.54 63.19 ZD1 6.17±0.08 1.42±0.03 a 1.43±0.09 a 1.14±0.03 b 3.99 23.04 23.16 18.46 64.66 ZD3 6.20±0.13 1.40±0.10 a 1.46±0.03 a 1.11±0.02 b 3.97 22.64 23.53 17.95 64.11 平均值 Mean values 6.20 1.41 1.45 1.13 3.98 22.66 23.24 18.08 63.98 -
[1] 张丹丹, 叶小辉, 赵峰, 等. 基于游离氨基酸组分的白茶滋味品质研究 [J]. 福建农业学报, 2016, 31(5):515−520. doi: 10.3969/j.issn.1008-0384.2016.05.014ZHANG D D, YE X H, ZHAO F, et al. Flavor and amino acids of brewed white teas [J]. Fujian Journal of Agricultural Sciences, 2016, 31(5): 515−520.(in Chinese) doi: 10.3969/j.issn.1008-0384.2016.05.014 [2] 陈志达, 周辉, 陈兴华, 等. 福鼎白茶滋味品质的量化评价 [J]. 浙江大学学报(农业与生命科学版), 2020, 46(3):334−343.CHEN Z D, ZHOU H, CHEN X H, et al. Taste quantitative evaluation of Fuding white tea [J]. Journal of Zhejiang University (Agriculture & Life Sciences), 2020, 46(3): 334−343.(in Chinese) [3] 周琼琼, 孙威江, 叶艳, 等. 不同年份白茶的主要生化成分分析 [J]. 食品工业科技, 2014, 35(9):351−354, 359.ZHOU Q Q, SUN W J, YE Y, et al. Study on the main biochemical components of white tea stored at different years [J]. Science and Technology of Food Industry, 2014, 35(9): 351−354, 359.(in Chinese) [4] 乔小燕, 李崇兴, 姜晓辉, 等. 不同等级CTC红碎茶生化成分分析 [J]. 食品工业科技, 2018, 39(10):83−89.QIAO X Y, LI C X, JIANG X H, et al. Comparative analysis on chemical characteristics of different grades CTC black tea [J]. Science and Technology of Food Industry, 2018, 39(10): 83−89.(in Chinese) [5] 向丽敏, 刘雅琼, 赖幸菲, 等. 不同茶类陈年茶的生化成分分析及其抗氧化活性 [J]. 现代食品科技, 2018, 34(4):56−62.XIANG L M, LIU Y Q, LAI X F, et al. Biochemical component analysis and antioxidant activities of different kinds of aged tea [J]. Modern Food Science and Technology, 2018, 34(4): 56−62.(in Chinese) [6] 王芳, 王飞权, 陈百文, 等. 冲泡条件对武夷肉桂生化成分浸出率和茶汤品质的影响 [J]. 食品工业, 2018, 39(1):72−75.WANG F, WANG F Q, CHEN B W, et al. Influence of brewing condition on the extraction rate and infusion quality of Wuyi-rougui tea [J]. The Food Industry, 2018, 39(1): 72−75.(in Chinese) [7] 眭红卫, 周圣弘. 冲泡方式对武夷岩茶茶多酚溶出量的影响研究 [J]. 食品研究与开发, 2017, 38(5):26−29. doi: 10.3969/j.issn.1005-6521.2017.05.006SUI H W, ZHOU S H. Impacts of brewing method on tea polyphenols dissolution in Wuyi rock tea [J]. Food Research And Development, 2017, 38(5): 26−29.(in Chinese) doi: 10.3969/j.issn.1005-6521.2017.05.006 [8] 曹燕妮, 茆慧敏, 尚旭岚, 等. 冲泡条件对青钱柳茶主要内含物浸出规律的影响 [J]. 南京林业大学学报(自然科学版), 2017, 41(4):19−24.CAO Y N, MAO H M, SHANG X L, et al. Effect of brewing conditions on the leaching rate of Cyclocarya paliurus tea compounds [J]. Journal of Nanjing Forestry University (Natural Science Edition), 2017, 41(4): 19−24.(in Chinese) [9] 郭桂义, 和红州, 赵文净, 等. 冲泡水温、时间和茶水比对信阳毛尖茶感官品质的影响 [J]. 食品科技, 2010, 35(7):120−123.GUO G Y, HE H Z, ZHAO W J, et al. Influence on organoleptic evaluation of Xinyang Maojian tea of brewing temperature, brewing time and ratio of tea and water [J]. Food Science and Technology, 2010, 35(7): 120−123.(in Chinese) [10] 黄明军, 杨新河, 覃彩芹, 等. 青砖茶4种品质成分溶出动力学研究 [J]. 湖北工程学院学报, 2016, 36(6):37−41. doi: 10.3969/j.issn.2095-4824.2016.06.008HUANG M J, YANG X H, QIN C Q, et al. Study on the digestion kinetics of four quality components in the qingzhuan brick tea [J]. Journal of Xiaogan University, 2016, 36(6): 37−41.(in Chinese) doi: 10.3969/j.issn.2095-4824.2016.06.008 [11] 孔祥瑞, 王让剑, 杨军, 等. 白茶感官品质与化学成分的相关和通径分析 [J]. 热带作物学报, 2013, 34(10):2014−2017. doi: 10.3969/j.issn.1000-2561.2013.10.028KONG X R, WANG R J, YANG J, et al. Correlation and path analysis on organoleptic quality and chemical components in white tea [J]. Chinese Journal of Tropical Crops, 2013, 34(10): 2014−2017.(in Chinese) doi: 10.3969/j.issn.1000-2561.2013.10.028 [12] 刘东娜, 罗凡, 李春华, 等. 白茶品质化学研究进展 [J]. 中国农业科技导报, 2018, 20(4):79−91.LIU D N, LUO F, LI C H, et al. Research progress on quality chemistry of chinese white tea [J]. Journal of Agricultural Science and Technology, 2018, 20(4): 79−91.(in Chinese) [13] 段红星, 孙围围. 福鼎白茶与景谷白茶内含成分与感官品质研究 [J]. 云南农业大学学报(自然科学版), 2016, 31(6):1091−1096.DUAN H X, SUN W W. Research on the components and sensory quality of fuding and jinggu white tea [J]. Journal of Yunnan Agricultural University (Natural Science), 2016, 31(6): 1091−1096.(in Chinese) [14] 陈曦, 刘乾刚. 白茶不同泡次茶汤中儿茶素、氨基酸组分的溶释 [J]. 福建茶叶, 2020, 42(6):12−16. doi: 10.3969/j.issn.1005-2291.2020.06.008CHEN X, LIU Q G. Dissolution and release of catechins and aminoacids in white tea infusions with different series of brewing [J]. Tea in Fujian, 2020, 42(6): 12−16.(in Chinese) doi: 10.3969/j.issn.1005-2291.2020.06.008 [15] 中华人民共和国国家质量监督检验检疫总局, 中国国家标准化管理委员会. 茶叶感官审评方法: GB/T 23776- 2018[S]. 北京: 中国标准出版社, 2018. [16] 中华人民共和国国家质量监督检验检疫总局, 中国国家标准化管理委员会. 茶水浸出物测定: GB/T 8305-2013[S]. 北京: 中国标准出版社, 2014. [17] 中华人民共和国国家质量监督检验检疫总局, 中国国家标准化管理委员会. 茶叶中茶多酚和儿茶素类含量的检测方法: GB/T 8313-2018[S]. 北京: 中国标准出版社, 2018. [18] 中华人民共和国国家质量监督检验检疫总局, 中国国家标准化管理委员会. 茶咖啡碱测定: GB/T 8312—2013[S]. 北京: 中国标准出版社, 2014. [19] 中华人民共和国国家质量监督检验检疫总局, 中国国家标准化管理委员会. 茶叶中茶氨酸的测定高效液相色谱法: GB/T 23193—2017[S]. 北京: 中国标准出版社, 2017. [20] 张正竹. 茶叶生物化学试验教程[M]. 北京: 中国农业出版社, 2009: 44-47, 52-53, 91-95. [21] ROBINSON K M, KLEIN B P, LEE S Y. Utilizing the R-index measure for threshold testing in model caffeine solutions [J]. Food Quality and Preference, 2005, 16(4): 283−289. doi: 10.1016/j.foodqual.2004.05.001 [22] DRAGICEVIC N, DELIC V, CAO C, et al. Caffeine increases mitochondrial function and blocks melatonin signaling to mitochondria in Alzheimer′s mice and cells [J]. Neuropharmacology, 2012, 63(8): 1368−1379. doi: 10.1016/j.neuropharm.2012.08.018 [23] 宛晓春. 茶叶生物化学[M]. 第3版. 北京: 中国农业出版社, 2003. [24] 陈丽如, 张娜, 杨更亮, 等. 茶色素的超声辅助提取及其稳定性研究 [J]. 江西农业大学学报, 2010, 32(3):608−612. doi: 10.3969/j.issn.1000-2286.2010.03.035CHEN L R, ZHANG, YANG G L, et al. A study on the ultrasound-associated extractions of tea pigment and Its stability [J]. Acta Agriculturae Universitatis Jiangxiensis, 2010, 32(3): 608−612.(in Chinese) doi: 10.3969/j.issn.1000-2286.2010.03.035 [25] 张月玲, 龚淑英, 邵晓林. 碧螺春茶的主要呈味物质浸出规律的研究 [J]. 茶叶, 2006,32(2):88−92. doi: 10.3969/j.issn.0577-8921.2006.02.008ZHANG Y L, GONG S Y, SHAO X L. A study on extractability of biluochun tea [J]. Journal of Tea, 2006,32(2): 88−92.(in Chinese) doi: 10.3969/j.issn.0577-8921.2006.02.008 [26] ZHANG H H, LI Y L, LV Y, et al. Influence of brewing conditions on taste components in Fuding white tea infusions [J]. Journal of the Science of Food and Agriculture, 2017, 97(9): 2826−2833. doi: 10.1002/jsfa.8111