贵州3种优良茶树品种的白茶适制性研究

Characteristics and optimized processing technology of white tea from 3 kinds of excellent tea varieties cultivated in Guizhou

中文关键词:  石阡苔茶  白茶  加工特性  复式萎凋  表没食子儿茶素没食子酸酯

英文关键词:Shiqian tai tea  white tea  characteristics  complex withering  epigallocatechin-3-gallate

中文摘要:

      目的 明确贵州广泛栽培的福鼎大白茶、龙井43和石阡苔茶的白茶适制性, 形成适合本地品种的白茶加工工艺, 以创制贵州特色白茶。方法 2023年5月下旬, 在室温18~22℃、外界温度18~26℃、湿度65%~75%条件下, 以福鼎大白茶、龙井43和石阡苔茶一芽二三叶鲜叶为原料, 室内萎凋槽加温萎凋、复式萎凋(日光萎凋和室内自然萎凋), 2种萎凋方式加工白茶, 3个萎凋时间(25、35、45 h)取样。感官审评后, 选取复式萎凋25、35、45 h茶样, 测定水浸出物、游离氨基酸、咖啡碱、茶多酚和儿茶素等生化成分含量。结果 游离氨基酸总量、咖啡碱和没食子酸随着萎凋时间的延长呈增加趋势; 茶多酚、表没食子儿茶素没食子酸酯、表儿茶素没食子酸酯和儿茶素总量随着萎凋时间的延长含量降低。石阡苔茶加工的白茶滋味和香气最优, 不同茶树品种复式萎凋35 h加工的白茶成分差异显著。石阡苔茶的水浸出物、茶多酚、咖啡碱、儿茶素总量、表没食子儿茶素没食子酸酯和表儿茶素没食子酸酯含量最高, 福鼎大白茶中的表没食子儿茶素和儿茶素含量最高, 龙井43的氨基酸含量最高。结论 3个茶树品种中, 石阡苔茶的白茶适制性最好, 最优加工工艺为复式萎凋、萎凋时间35 h。

英文摘要:

      Objective To clarify the characteristic of white tea from three tea varieties widely cultivated in Guizhou, including Fuding white tea, Longjing 43 and Shiqian tai tea, form optimized processing technology and Guizhou white tea with local characteristics. Methods At May 2023, a bud of two and three tea leaves of Fuding white tea, Longjing 43 and Shiqian tai tea were processed by two types of withering methods, including indoor heating withering and complex withering (daylight withering and indoor natural withering) with the room temperature of 18–22℃, external temperature of 18–26℃, humidity of 65%–75%. The sensory evaluation of tea samples collected at 3 withering times (25, 35, 45 h) were performed. The content of water extract, free amino acids, caffeine, tea polyphenols and catechins were also determined in 25, 35 and 45 h tea samples processed by complex withering. Results The results indicating that the content of total free amino acids, caffeine and gallic acid increased with the prolong of withering time, the total amount of tea polyphenols, epigallocatechin-3-gallate, epicatechin gallate and catechin decreased with withering time. The taste and aroma of white tea processed by Shiqian tai tea were the best. There were obvious differences in the composition of white tea processed by different tea varieties at complex withering time of 35 h. The content of water extract, tea polyphenols, caffeine, catechins, epigallocatechin-3-gallate and epicatechin gallate in Shiqian tai Tea were the highest, the content of epigallocatechin and catechin in Fuding white tea were the highest, and the amino acid content of Longjing 43 was the highest. Conclusion These results indicate that Shiqian tai tea has the greatest potential for processing into white tea in 3 tea varieties, and the optimal processing technology is complex withering for 35 h.