代表性黄白化品种扁形绿茶化学品质特征解析

Chemical quality characteristics of flat green tea made by representative etiolation and albino

目的探究不同黄白化品种扁形绿茶主要化学成分差异及其汤色、滋味特征。方法采用超高效液相色谱-三重四极杆串联质谱法(ultra performance liquid chromatography-tandem quadrupole mass spectrometry,UPLC-TQ-MS)和紫外-可见分光光度法等方法对不同黄白化品种扁形绿茶的主要水溶性成分进行定量测定,并结合感官分析和色差分析,探讨白叶1号和中黄系列品种制作的扁形绿茶的化学成分差异及其与汤色、滋味特征的内在联系。结果普通绿茶品种(龙井43)、黄化品种(中黄系列)和白化品种(白叶1号)按照扁形绿茶工艺制得扁形绿茶,其茶多酚总量与氨基酸总量比值(酚氨比)的平均值分别为3.93、3.33(黄化品种比值范围为2.93~3.91)和2.59。化学成分分析显示,白叶1号和中黄系列扁形绿茶的主要差异成分为槲皮素糖苷(总量分别为3.11和3.86 mg/g)、半乳糖基黄酮糖苷(总量分别为1.21和2.32 mg/g)和非酯型儿茶素(总量分别为24.83和15.85 mg/g),均差异显著(P<0.05)。感官审评和色差分析表明,白叶1号和中黄系列相对于龙井43更鲜爽、鲜醇;白叶1号的涩味低于中黄系列,且汤色黄度更低。结论黄白化品种扁形绿茶的酚氨比整体上低于普通品种扁形绿茶,其中白叶1号与龙井43扁形绿茶化学成分含量差异最大,黄化品种中的中黄4号与龙井43扁形绿茶相近。黄化品种与白化品种制作的扁形绿茶相比,茶氨酸、非酯型儿茶素、槲皮素糖苷和半乳糖基黄酮糖苷是其主要差异成分。

Objective To explore the differences of main chemical components and the characteristics of tea infusion color and taste of different etiolated and albino flat green tea.Methods The main water-soluble components of the etiolated and albino flat green tea were quantitatively determined by ultra performance liquid chromatography-tandem quadrupole mass spectrometry(UPLC-TQ-MS)and ultraviolet-visible spectrophotometry.In addition,the differences in chemical composition of the flat green tea made by albino variety(BY1)and etiolated variety(ZH series)and the internal relations with the characteristics of tea infusion color and taste were discussed based on the sensory analysis and color difference analysis.Results The phenol-ammonia ratio of flat green tea made by green leaf variety(LJ43),ZH series and BY1 were 3.93,3.33(etiolated variety ratio ranged from 2.93 to 3.91)and 2.59,respectively.Chemical analysis showed that total content of quercetin glycosides(3.11 and 3.86 mg/g,respectively),total content of galactosyl flavonoid glycosides(1.21 and 2.32 mg/g,respectively)and non-ester catechins(24.83 and 15.85 mg/g,respectively)were the main differential components of BY1 and ZH series flat green tea,and the difference was significant(P<0.05).Sensory evaluation and color difference analysis showed that BY1 and ZH series were fresher and tastier than LJ43;BY1 had lower astringency than ZH series,and the color of the tea infusion was more yellow.Conclusion The phenol-ammonia ratio of the etiolated and albino flat green tea is lower than green leaf made flat green tea in general.The chemical composition of BY1 and LJ43 flat green tea has the largest difference,while the etiolated tea ZH4 is similar to that of LJ43.Theanine,non-ester catechins,quercetin glycosides and galactosyl flavonoid glycosides are the main differential components of the flat green tea made by etiolated and albino varieties.