不同叶位芽叶在工夫红茶加工过程中理化品质的变化  

Changes in the Physicochemical Properties of One Bud and Two Leaves at Different Leaf Positions during Congou Black Tea Processing

作　　者：周静芸 黄瑞 欧阳珂 陆安霞 陈林木 童华荣[1] ZHOU Jingyun;HUANG Rui;OUYANG Ke;LU Anxia;CHEN Linmu;TONG Huarong(College of Food Science,Southwest University,Chongqing 400715,China;Faculty of Agriculture,Forestry and Food Engineering,Yibin University,Yibin 644000,China)

机构地区：[1]西南大学食品科学学院,重庆400715 [2]宜宾学院农林与食品工程学部,四川宜宾644000

出　　处：《食品科学》2023年第1期53-62,共10页Food Science

基　　金：重庆市现代山地特色高效农业茶叶产业技术体系项目(2020-7)。

摘　　要：本实验以福鼎大白茶茶树品种鲜叶为原料,通过叶片微观结构观察和理化指标测定,探究工夫红茶加工过程中不同叶位芽叶的理化品质变化。结果发现:不同叶位芽叶的色泽从揉捻开始由绿逐渐变红,但第二叶的红变程度弱于其他部分;叶片结构和酚类化合物分析结果表明,第一、二叶的叶肉细胞及叶绿体结构均在揉捻时被破坏,说明第一、二叶均从揉捻阶段开始发酵;在加工过程中茶多酚质量分数、儿茶素类含量均下降,茶黄素含量和茶红素含量先增后减,之后趋于稳定,茶褐素含量一直增加,且均在揉捻时含量变化最大;第一叶与第二叶的儿茶素类总量、表没食子儿茶素、表没食子儿茶素没食子酸酯、表儿茶素没食子酸酯的氧化率及茶黄素含量差异不显著(P>0.05),说明不同叶位叶片的发酵程度无明显差异;叶绿素a、叶绿素b含量以及叶绿素类总量均下降,脱镁叶绿素、脱镁脱叶绿醇基叶绿素含量均上升;加工过程中第二叶的叶绿素组分含量均显著高于第一叶(P<0.05)。本研究结果可为加工优质工夫红茶、提高茶树鲜叶的利用率提供一定的理论依据。Fresh leaves of Fuding Dabai tea(Camellia sinensis(L.))consisting of one bud and two leaves were used to manufacture Congou black tea,and the changes in the physicochemical properties and microstructure of the bud and the two leaves were explored during the manufacturing process.It was found that during the rolling process,the color of the bud and the leaves gradually turn from green to red,but the degree of color change of the lower leaf was lower than that of the bud and the upper leaf.Besides,optical microscopic(OM)and transmission electron microscopic(TEM)analysis showed the structures of mesophyll cells and chloroplasts in both leaves were destroyed in the rolling process,indicating the beginning of fermentation.The chemical composition analysis showed that during the Congou black tea manufacturing process,the contents of tea polyphenols and catechins decreased,the contents of theaflavins and thearubigins increased at first,then decreased and finally leveled off,and the content of theabrownins kept increasing;the contents of all these compounds changed most during rolling.There was no significant difference in the oxidation degree of total catechins,epigallocatechin,epigallocatechin gallate,epicatechin gallate and theaflavins between the two leaves(P>0.05),indicating that their fermentation degrees were similar.During the entire process,the contents of chlorophyll a,chlorophyll b and total chlorophyll decreased and the contents of pheophytin and pheophorbide increased for the bud and the leaves.The content of chlorophylls in the lower leaf was always much higher than that in the upper leaf(P<0.05).This study provides a theoretical basis for processing high-quality congou black tea by improving the utilization rate of fresh tea leaves.

关 键 词：品质 叶片结构 青张 叶绿素 工夫红茶 

分 类 号：TS272.4[农业科学—茶叶生产加工]