景迈山7个村寨古树茶的品质特征

Quality Characteristics of Ancient Tree Tea in Seven Villages of Jingmai Mountain

【目的】初步探究景迈山古树茶的品质特征。【方法】选取景迈山7个主要村寨茶园,按照一芽两叶的标准采摘制作成晒青毛茶;采用顶空固相微萃取法—气相色谱—质谱法(HS-SPME-GC-MS)对茶样挥发性物质进行筛选和分类,采用常规方法测定理化成分,并结合感官审评对茶叶品质进行分析。【结果】共检测出45种香气物质,主要包括醇类、碳氢类、氧杂环类、芳香烃类、酮类、醛类等。筛选出16种具有香气特征的物质,可分为果香、木香(清香)和花香3种类型,除芒景下寨未检测出花香型外,其余村寨均含有上述3种香气特征物质,形成晒青茶的“花蜜香”。景迈山晒青茶平均含水量7.91%,水浸出物含量52.35%,游离氨基酸含量2.67%,茶多酚含量26.75%,可溶性糖含量7.60%,咖啡碱含量49.62 mg/g,没食子酸含量1.62 mg/g,黄酮含量6.50%,总儿茶素含量197.87 mg/g。【结论】景迈山古树茶理化成分含量均存在一定差异,可根据特有香气成分以及理化成分判别茶样来源。研究结果为景迈山古树茶品质预测模型的建立以及品质研究奠定了基础。

[Purpose]To explore the quality characteristics of ancient tree tea in Jingmai Mountain.[Methods]Seven main village tea gardens in Jingmai Mountain were selected and picked according to the standard of one bud and two leaves to make sun-dried green tea.The volatile component of tea samples were screened and classified by headspace solid phase microextraction-gas chromato-graphy-mass spectrometry(HS-SPME-GC-MS).The physicochemical components were determined by conventional methods,and the quality of tea was analyzed by sensory evaluation.[Results]A total of 45 aroma substances were detected,including alcohols,hydrocarbons,oxygen heterocycles,aromatic hydrocarbons,ketones and aldehydes.A total of 16 substances with aroma characteristics were screened out,which could be divided into fruit aroma,woody aroma(fragrance)and floral aroma.Excepted for the floral aroma type not detected in Mangjingxiazhai,the other villages all contained the above three aroma characteristic substances,forming the“nectary aroma”of sun-dried green tea.The average water content of the tea samples was 7.91%,water extract content was 52.35%,free amino acid content was 2.67%,tea polyphenol content was 26.75%,soluble sugar content was 7.60%,caffeine content was 49.62 mg/g,gallic acid content was 1.62 mg/g,flavonoids content was 6.50%,and total catechins were 197.87 mg/g.[Conclusion]There are certain differences in the physicochemical components of the ancient tree tea from Jingmai Mountain,which can be used to determine the source of the tea based on unique aromatic components and physicochemical components.The results have laid the foundation for the establishment of a quality prediction model and further studies on the quality of Jingmai Mountain ancient tree tea.