摘要
六堡茶是一种产自广西六堡的微生物发酵型茶叶,其有别于其他茶叶的最主要环节是长达半年至3年的窖藏。为研究六堡茶加工过程中关键成分的变化,分析了不同生产阶段的六堡茶中总多糖、咖啡碱、总多酚及茶黄素等主要成分的含量差异;并基于超高效液相色谱-四级杆静电场轨道阱质谱系统(UPLC-Q-Exactive)结合主成分分析方法,探究渥堆发酵及窖藏工艺中六堡茶化学成分变化规律。结果表明,六堡茶原料经过渥堆发酵后,总多糖含量上升,由0.63%上升至2.15%;窖藏后,含量变化不大。咖啡碱含量整体变化差异不大,含量为1.96%~2.15%。原料中的总多酚含量为20.73%,渥堆发酵后下降为17.93%;窖藏后,含量下降为12.62%,整体呈现出下降的趋势。渥堆发酵后茶黄素含量由原料的0.05%上升至0.21%,窖藏后再次下降至0.10%,整体较原料呈升高趋势。主成分分析结果表明,渥堆发酵及窖藏前后的六堡茶样品与原料能够良好区分,表明其化学成分随渥堆发酵及窖藏过程产生显著变化。通过数据库比对,从渥堆发酵及窖藏后差异较大的化合物中共鉴定出29种化合物,包括酚酸类、黄烷醇类、黄酮及黄酮苷类物质。其中预测为部分酚酸类、黄酮及苷类的物质,其相对含量在渥堆发酵环节下降,而在窖藏环节重新回升。揭示了六堡茶中主要成分在关键工艺环节的变化规律,为定义品质关键成分、预测健康功效提供了科学数据。
Liupao tea is a kind of fermented tea from Liupao Guangxi.The key process of Liupao tea was the maturation with 6 to 36 months.This study was aimed to explore the variation of Liupao tea during fermentation using ultra high performance liquid chromatography quadrupole Orbitrap mass spectrometry combined with principal component analysis and the method of materials detection.The results showed that,the content of tea polysaccharide increased during fermentation(from 0.63%to 2.15%),and remained unchanged after maturation.The content of caffeine appeared no significant change during the whole process.After fermentation,the content of tea polyphenols decreased from 20.73%to 17.93%and 12.62%.The content of theaflavins increased firstly during fermentation(0.05%to 0.21%)and then decreased in the process of maturation(0.21%to 0.10%).The score plot of principal component analysis(PCA)indicated that Liupao tea samples could be separated with the raw materials because of the variation of main components.29 compounds including the phenolic acids,flavanols and flavonoids were identified using the database library.Among these compounds,the relative content of a portion of phenolic acids and flavonoids decreased after fermentation and then increased in the process of maturation.This study revealed the change rule of the main components in the key process of Liupao tea and provided basis for defining the key quality components and predicting the health effects.
作者
张均伟
侯粲
杜昱光
肖杰
郝彬秀
谢加仕
肖思思
应剑
ZHANG Junwei;HOU Can;DU Yuguang;XIAO Jie;HAO Binxiu;XIE Jiashi;XIAO Sisi;YING Jian(China Tea(Wuzhou)Co.,Ltd,Wuzhou 543001;Nutrition and Health Research Institute,COFCO Ltd.,Beijing 102209;Key Laboratory of Biopharmaceutical Production&Formulation Engineering,PLA and State Key Laboratory of Biochemical Engineering,Institute of Process Engineering,Chinese Academy of Sciences,Beijing 100190;Beijing Key Laboratory of Nutrition&Health and Food Safety,Beijing 102209;China Tea Technology(Beijing)Co.,Ltd.,Beijing 102209)
出处
《食品科技》
CAS
北大核心
2019年第12期328-334,共7页
Food Science and Technology
基金
中粮集团重大项目
科技创新创业开发平台后补贴项目((001)2018-G2-T005*).
关键词
六堡茶
渥堆发酵
窖藏
高分辨质谱
物质基础
Liupao tea
fermentation
maturation
high-resolution mass spectrometry
chemical basis
