摘要
游离氨基酸是贡献茶汤鲜味的主要物质。乔木型和灌木型古茶树茶鲜叶经红茶加工工艺制成的干茶,其鲜味特征突出,但目前对古茶树茶鲜叶及制成的干茶中游离氨基酸的积累特征尚不清楚。本研究基于高效液相色谱-荧光检测器(HPLC-FLD)结合化学计量学方法靶向分析乔木型、灌木型古茶树及福鼎大白茶鲜叶和干茶样品中18种游离氨基酸含量。结果表明,茶鲜叶和干茶样品中茶氨酸含量最高,且在乔木型和灌木型古茶树鲜叶中存在显著差异;干茶中鲜味氨基酸含量减少,甜味和苦味氨基酸含量变化不明显。主成分分析结果显示,茶鲜叶样品游离氨基酸含量聚类明显,而干茶则呈现重叠或分散特征。不同树型古茶树鲜叶游离氨基酸积累存在差异,加工可改变游离氨基酸代谢,促进红茶品质形成。
Free amino acids are the main substances contributing to the umami of tea infusion. Dried tea processed by black tea processing technique, with fresh leaves of ancient tea trees of arbor type and shrub type show outstanding characteristics in umami, but the accumulation characteristics of free amino acid content in the fresh leaves of ancient tea trees and the dried tea are still unclear. In this study, contents of 18 free amino acids in fresh leaves and dried tea samples from ancient tea trees of arbor type, shrub type and Fudingdabai were targeted and analyzed based on high performance liquid chromatography-fluorescence detection(HPLC-FLD) combined with chemometric method. The results showed that, content of theanine was the highest in samples of fresh tea leaves and dried tea leaves, and there were significant differences between the fresh leaves from ancient tea trees of arbor type and shrub type. The content of umami amino acids decreased in dried tea, while the contents of sweet and bitter amino acids varied irregularly. Principal component analysis showed that, the fresh leaf samples clustered significantly according to free amino acid content, while the dried tea showed overlapping or scattered characteristics. There were differences in the accumulation of free amino acids in fresh leaves of different tree types of ancient tea trees, and processing could change free amino acid metabolism to promote quality formation of black tea.
作者
方仕茂
张拓
杨婷
田小强
田洪军
刘忠英
潘科
FANG Shi-mao;ZHANG Tuo;YANG Ting;TIAN Xiao-qiang;TIAN Hong-jun;LIU Zhong-ying;PAN Ke(Tea Research Institute,Guizhou Academy of Agricultural Sciences,Guiyang 550006,China;Ecological Tea Development and Technical Guidance Center of Yanhe Tujia Autonomous County,Yanhe 565300,China)
出处
《江苏农业学报》
CSCD
北大核心
2022年第4期1070-1077,共8页
Jiangsu Journal of Agricultural Sciences
基金
贵州省农业科学院基金项目[黔农科院青年科技基金(2021)29]
贵州省科技支撑项目[黔科合成果(2021)一般030、黔科合支撑(2020)1Y146]。
关键词
古茶树
红茶
高效液相色谱-荧光检测器
游离氨基酸
鲜甜
ancient tea tree
black tea
high performance liquid chromatography-fluorescence detection(HPLC-FLD)
free amino acid
umami and sweet
