不同紫芽茶叶香气成分分析

Aroma components in different purple bud teas

【目的】对比分析不同加工工艺下不同品种紫芽茶叶香气成分及含量的差异,旨在进一步了解加工工艺与茶树品种对紫芽茶叶香气成分的影响,为紫芽茶叶加工技术提升及香气品质调控提供参考依据。【方法】以乌牛早、南山白毛和紫娟3种茶树品种的紫色芽叶制成的4类茶样[直接烘干茶(对照)、绿茶、白茶、红茶]为研究对象,采用顶空固相微萃取—气相色谱—质谱联用(HS-SPME-GC-MS)技术测定其香气成分,结合感官审评,分析加工工艺与茶树品种对紫芽茶叶香气成分及含量的影响。【结果】乌牛早绿茶感官品质综合表现最佳,总分为90.65分。从12个茶样中共检测出40种香气成分,其中醇类和醛类在香气成分含量及种类上占据主导地位,酯类、烯烃类、酮类和其他类的种类及含量均较少。醇类和醛类相对含量最高分别为84.37%(乌牛早对照)和13.44%(乌牛早红茶)。β-芳樟醇、氧化芳樟醇(呋喃型)、脱氢芳樟醇、香叶醇、橙花叔醇、苯甲醛和水杨酸甲酯等成分相对含量较高;β-芳樟醇和氧化芳樟醇在绿茶中相对含量较低,脱氢芳樟醇和烯烃类物质在绿茶中相对含量较高;不同品种紫芽茶叶的β-芳樟醇相对含量排序为乌牛早>紫娟>南山白毛,相对含量最高为54.05%(乌牛早对照),最低为19.10%(南山白毛绿茶);氧化芳樟醇(呋喃型)在南山白毛茶样中相对含量较高,其中在南山白毛白茶与南山白毛红茶中相对含量相差较小;不同品种紫芽茶叶的香叶醇相对含量排序为乌牛早>南山白毛>紫娟,相对含量最高为6.39%(乌牛早红茶),最低为1.76%(紫娟白茶);醛类在紫娟茶样中总含量相对较低。在所有茶样中,检测出26种共有香气成分,且共有香气成分间均呈极显著正相关(P<0.01)。【结论】受加工工艺与茶树品种的影响,12个紫芽茶叶香气成分和含量存在一定差异,同种香气成分在不同茶类中含量也有所不同。乌牛早紫芽用于制备绿茶具有一定优势,而南山白毛紫芽与紫娟紫芽均适合用于制备白茶。

【Objective】To analyze and compare the difference of aroma components and contents in different processing technology and varieties of purple bud tea,in order to further understand the influence of processing technology and tea plant varieties on the aroma components of purple bud tea,and provide reference for the improvement of processing technology and the control of aroma quality of purple bud tea.【Method】Four types of tea samples[direct drying tea(control),green tea,white tea,black tea]made from the purple buds and leaves of three tea tree varieties of Wuniuzao,Nanshan Baimao and Zijuan as the research objects,using the headspace solid phase microextraction-gas chromatograph-mass spectrometry(HS-SPME-GC-MS)technology to determine its aroma components,combined with sensory evaluation,analyze the effects of processing technology and tea varieties on the aroma components and content of purple buds.【Result】The sensory quality of Wuniuzao green tea was the best,the total score was 90.65.A total of 40 aroma components were detected from12 tea samples.Among them,alcohols and aldehydes dominated the contents and types of aroma components,while the types and contents of esters,olefins,ketones and others were less.The highest relative contents of alcohols and aldehydes were 84.37%(control of Wuniuzao)and 13.44%(Wuniuzao black tea)respectively.The content ofβ-linalool,oxidizes linalool(furan type),dehydrolinalool,geraniol,nerolidol,benzaldehyde and methyl salicylate were relatively high.The contents ofβ-linalool and linalool oxide in green tea were relatively low,and the contents of dehydrolinalool and olefins were relatively high.The contents of linalool of different varieties of purple bud tea trees ranked as Wuniuzao>Zijuan>Nanshan Baimao,the highest relative content was 54.05%(control of Wuniuzao),the lowest was 19.10%(Nanshan Baimao green tea).Oxidized linalool(furan type)content was relatively high in Nanshan Baimao tea,and the relative content in Nanshan Baimao white tea and Nanshan Baimao black tea was not much different.The content of geraniol ranked as Wuniuzao>Nanshan Baimao>Zijuan,the highest relative content was 6.39%(Wuniuzao black tea),and the lowest was 1.76%(Zijuan white tea).The total content of aldehydes in Zijuan tea samples was relatively low.In all tea samples,26 common aroma components were detected.There were extremely significant correlation(P<0.01)among shared aroma components of different purple bud tea samples.【Conclusion】Affected by the processing technology and tea varieties,the aroma components and contents of the 12 purple bud teas are different,and the contents of the same components in different teas are also different.The purple bud of Wuniuzao has certain advantages for the preparation of green tea,while the purple bud of Nanshan Baimao and Zijuan are both suitable for the preparation of white tea.