六大茶类天然茶汤纳米聚集特性研究
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- 英文论文题名：Profiling on nano-aggregation in natural tea infusions of six Chinese teas
- 论文作者：林晓蓉 ; 罗维 ; 陈忠正 ; 张媛媛 ; 李斌
- 英文论文作者：Lin Xiaorong ; Luo Wei ; Chen Zhongzheng ; Zhang Yuanyuan ; Li Bin ; College of Food Science ; South China Agricultural University
- 年：2016
- 作者机构：华南农业大学食品学院;
- 论文关键词：茶叶 ; 纳米聚集体 ; 茶沉淀
- 英文论文关键词：camellia sinensis ; nano-aggregates ; tea cream
- 会议召开时间：2016-11-09
- 会议录名称：中国食品科学技术学会第十三届年会论文摘要集
- 英文会议录名称：Abstracts of the 13th Annual Meeting of CIFST
- 语种：中文
- 分类号：TS272.5;TB383.1
- 学会代码：ZGSP
- 会议名称：中国食品科学技术学会第十三届年会
- 会议地点：中国北京
- 主办单位：中国食品科学技术学会
- 学会名称：中国食品科学技术学会
- 页数：2
- 文件大小：105k
- 原文格式：O
- 会议级别：全国
摘要
茶汤纳米聚集体是茶多酚、蛋白质等自组装形成的纳米级胶粒,是介于游离分子与沉淀颗粒的中间状态,是揭示茶饮料沉淀形成机理的关键,但现有研究仍十分有限。茶汤理化组成是纳米聚集体形成的化学基础,为探究茶汤纳米聚集体的形成机制,本研究以绿茶、白茶、黄茶、乌龙茶、红茶和普洱茶六大茶类为比对材料,以茶汤纳米聚集体为研究对象:采用透射电子显微镜、动态光散射等技术表征其物理化学特性,采用HPLC、原子吸收光谱等技术分析其理化组成,比较并探讨各组分对纳米聚集体形成的影响。结果表明:六大茶类茶汤均存在大量平均直径为70~350 nm、表面带负电荷的球型纳米聚集体,其以蛋白质、茶多酚为主体成分,但以蛋白质、金属元素Fe、Cu对胶粒形成的贡献较大;各茶类纳米聚集体的直径、形态、理化组成均存在显著差异。本文系统表征了各茶类纳米聚集体的基本特性和理化组成,为从纳米聚集体角度深入揭示茶沉淀形成的分子互作机理及六大茶类的功能特性提供前期研究基础。
Tea nano-aggregates were spontaneously-assembled nano-colloidal particles derived from molecular interactions among tea polyphenols,proteins and other components in natural tea infusions,which were transitional forms between free molecules and precipitation.These peculiar pre-creaming nanoparticles provided a novel perspective for the elucidation of the formation of tea cream.To explore the underlying mechanism of tea nano-aggregation,a group of tea infusions of different chemical composition were extracted from green tea,white tea,yellow tea,oolong tea,black tea,and Pu-er tea.Primarily,a great number of negatively-charged colloidal particles of 70 ~ 350 nm in diameter were confirmed in these tea infusions by Transmission Electron Microscopy,Dynamic Light Scattering and Laser Doppler Velocimetry.In addition,phytochemical determination via High Performance Liquid Chromatography and Flame Atomic Absorption Spectrometry shown that proteins and tea polyphenols were the principal constituents of nano-aggregates from six teas,though other chemicals in tea infusions like methylxanthines,carbohydrates,free amino acids and minerals were also involved in tea nano-aggregation.Furthermore,proteins,Fe and Cu were inferred to play key roles in the formation of tea nanoaggregates of various tea infusions based on their distribution coefficients from tea nano-aggregates to supernatants.The present study would provide primary physicochemical and phytochemical evidences for further investigation of molecular interactions in the precipitation of tea beverages.
Tea nano-aggregates were spontaneously-assembled nano-colloidal particles derived from molecular interactions among tea polyphenols,proteins and other components in natural tea infusions,which were transitional forms between free molecules and precipitation.These peculiar pre-creaming nanoparticles provided a novel perspective for the elucidation of the formation of tea cream.To explore the underlying mechanism of tea nano-aggregation,a group of tea infusions of different chemical composition were extracted from green tea,white tea,yellow tea,oolong tea,black tea,and Pu-er tea.Primarily,a great number of negatively-charged colloidal particles of 70 ~ 350 nm in diameter were confirmed in these tea infusions by Transmission Electron Microscopy,Dynamic Light Scattering and Laser Doppler Velocimetry.In addition,phytochemical determination via High Performance Liquid Chromatography and Flame Atomic Absorption Spectrometry shown that proteins and tea polyphenols were the principal constituents of nano-aggregates from six teas,though other chemicals in tea infusions like methylxanthines,carbohydrates,free amino acids and minerals were also involved in tea nano-aggregation.Furthermore,proteins,Fe and Cu were inferred to play key roles in the formation of tea nanoaggregates of various tea infusions based on their distribution coefficients from tea nano-aggregates to supernatants.The present study would provide primary physicochemical and phytochemical evidences for further investigation of molecular interactions in the precipitation of tea beverages.
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