基于代谢组学方法的冬桑复合茶化学成分比较分析

Comparative analysis of chemicals of blended mulberry-leaf teas based on metabolomics approach

中文关键词:  冬桑复合茶  香气  非挥发性成分  代谢组学

英文关键词:blended mulberry-leaf teas  aroma components  non-volatile components  metabolomics

中文摘要:

      目的 基于代谢组学方法系统解析冬桑复合茶(mulberry-leaf teas, MTs)关键化学成分, 并通过与感官结果结合阐明其中潜在风味成分。方法 本研究采集了市售冬桑、绿茶、乌龙茶和红茶原料, 冬桑绿茶复合茶、冬桑乌龙茶复合茶和冬桑红茶复合茶样本。采用搅拌棒吸附萃取(stir bars orptive extraction, SBSE)富集样品中的挥发性成分, 热解析附后, 采用气相色谱-质谱法(gas chromatography-mass spectrometry, GC-MS)进行分析, 并采用基于超高效液相色谱-串联四极杆飞行时间质谱法(ultra performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry, UPLC-QToF/MS)的代谢组学技术全面解析MTs的关键香气成分及非挥发性品质成分。结果 冬桑绿茶中β-环柠檬醛、橙花醇和2-甲基丁酸顺式-3-己烯酯, 冬桑乌龙茶中2-壬烯醛、苯甲醛、香叶醛和芳樟醇, 冬桑红茶中芳樟醇、脱氢芳樟醇、4-萜品醇、α-松油醇、橙花醇和香叶醇等香气成分是构成复合茶的香气关键成分。此外, 共鉴定出73个黄酮类、36个有机酸类、21个脂类、18个萜类和苯丙烷类、15个糖类、8个生物碱类、7个氨基酸类以及5个脂溶性色素类成分, 筛选出15个变量投影重要性指标大于1的特征性成分, 特别是(+)-没食子儿茶素、槲皮素3-O-槐糖、原花青素C1、表没食子儿茶素没食子酸酯、表儿茶素(4α-8)儿茶素、槲皮素3,7-糖苷、二氢杨梅素、山奈酚-3-鼠李糖苷、dTDP-6-脱氧-D-糖、D-岩藻糖、二羟基-1(10)-螺环戊烯-2-酮11-糖苷、PI (16: 0/18: 2(9Z, 12Z)、PG (16: 0/18: 3(6Z, 9Z, 12Z)) (L10)、对羟基奎尼酸、抗坏血酸等桑叶特征性成分, 这些非挥发性成分是直接或间接贡献复合茶滋味的关键成分。结论 本研究系统解析了传统茶与冬桑叶拼配的复合茶关键风味物质基础及其对特征风味品质的潜在贡献, 为优化茶与冬桑复合配方提供科学依据, 拓展茶跨界组合应用提供理新思路。

英文摘要:

      Objective To analyze the crucial chemicals of blended mulberry-leaf teas (MTs) by metabonomics, and elucidate the potential flavor compounds by combining sensory evaluation. Methods In this study, commercial samples of winter mulberry leaves with traditional green tea, Oolong tea, black tea, blended mulberry-leaf green tea, blended mulberry-leaf Oolong tea, and blended mulberry-leaf black tea were colloected as raw materials. Stir bars orptive extraction (SBSE) was used to extract the volatile components from the samples, gas chromatography-mass spectrometry (GC-MS) was used for analysis after pyrolysis and adsorption, the metabolomics approaches based on ultra performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry (UPLC-QToF/MS) was used to analyze the key aroma components and non-volatile quality components of MTs. Results The β-cyclocitral, nerol and cis-3-hexenyl 2-methylbutyrate increased significantly in blended mulberry leaf-green tea; the 2-nonenal, benzaldehyde, geranial, and linalool in blended mulberry leaf-Oolong tea; the linalool, dehydrolinalool, 4-terpenol, α-terpineol, nerol, and geraniol in blended mulberry-leaf black tea were provend as crucial aroma components of the MTs. In addition, the non-volatile components in MTs were further identified, including 73 kinds of flavonoids, 36 kinds of organic acids, 21 kinds of lipids, 18 kinds of terpenoid and phenylpropanoid volatiles, 15 kinds of sugars, 8 kinds of alkaloids, 7 kinds of amino acids and 5 kinds of lipid-soluble pigments. Multivariate statistical analysis was proceeded, and 15 kinds of characteristic metabolites with variable importance in projection greater than 1 were screened out, including (+)-epigallocatechin, quercetin 3-O-sophorose, procyanidin C1, epigallocatechin gallate, epigallocatechin-(4α-8)-catechin, quercetin 3,7-glycoside, dihydromyricetin, kaempferol-3-rhamnoside, dTDP-6-deoxy-D-sugar, D-fucose, dihydroxy-1 (10)-spiropenene-2-one 11-glycoside, PI (16:0/18:2 (9Z,12Z), PG (16:0/18:3 (6Z,9Z,12Z)) (L10), p-hydroxyquinic acid, and ascorbic acid which speculated as crucial taste-acive components. Conclusion In conclusion, this study had systematically analyzed the chemical basis of the key quality of MTs, as well as their potential contributions to the flavor characteristics and flavor quality. It will provide a scientific basis for optimizing blending formulation, and offer a theoretical new idea for expanding the cross-border combination and application of tea and other herbals.