茶鲜叶萎凋过程中摊青工艺对白茶品质的影响  

Effects of the leaf-spreading process on the quality of white tea during the withering of fresh tea shoots

作　　者：项丽慧 宋振硕[1] 张应根[1] 王丽丽[1] 陈键[1] 陈林[1] XIANG Lihui;SONG Zhenshuo;ZHANG Yinggen;WANG Lili;CHEN Jian;CHEN Lin(Tea Research Institute,Fujian Academy of Agricultural Sciences,Fuzhou 350013,China)

机构地区：[1]福建省农业科学院茶叶研究所,福州350013

出　　处：《农业工程学报》2023年第7期266-274,共9页Transactions of the Chinese Society of Agricultural Engineering

基　　金：福建省自然科学基金项目(2020J011364);福建省属公益类科研院所基本科研专项(2019R1029-5和2020R1029008);福建省农业科学院科技创新团队项目(CXTD2021004-2)。

摘　　要：为探明茶鲜叶萎凋过程中摊青工艺对白茶风味品质和生化成分的影响,在控温除湿环境中以基于静态摊晾于水筛加工而成的白茶为对照,在不同茶鲜叶减重率(65%、70%和75%)时对在制品进行并筛或堆青处理。结果表明,各处理制成的白茶呈现出较为相似的感官品质特征,但堆青处理相较并筛处理及对照茶样的香气鲜度下降而滋味甜度提高。在并筛处理中以在减重率为70%时并筛略优于在减重率为65%时并筛的白茶品质,且二者均以薄并筛处理较优于对照茶样。在减重率达75%时对在制品进行相同时长不同厚度的堆青处理(堆青方式:2~6筛并1筐)以厚堆处理的白茶品质较优,而不同时长相同厚度的堆青处理(堆青时长:2~6 d)则以短时堆青的白茶品质为佳。不同摊青处理白茶的儿茶素类、生物碱和主要氨基酸组分无明显规律性差异。相较静态/并筛工艺组,堆青工艺组茶样中呈甜味的脯氨酸和苯乙醇、橙花醇、香叶醇等花果香成分显著降低(P<0.05)。基于茶样生化组成的模式识别可将全部供试茶样划分成静态/并筛工艺组与堆青工艺组2种类群。堆青处理可通过促进脂肪酸代谢,增加烷烃类、降异戊二烯类和醛类化合物含量来有效调节白茶样品的生化组成;橙花醇、橙花醛和香草醛等23种化合物可视为其与静态/并筛工艺组茶样相互区分的主要特征标识物(群)。研究结果可为基于摊青方式的白茶风味品质工艺技术调控提供参考依据。This study aims to investigate the effect of the leaf-spreading process on the flavor quality and biochemical components of white tea during withering.Under the indoor air conditions preset at 20-22℃and 55%-65%relative humidity(RH),the static withering on bamboo sieves(0.5 kg fresh leaves per sieve:diameter(Φ)=90 cm)was used as the control(Immobility).Tea samples were acquired by thin or thick piling-up,namely Bingshai or Duiqing when the weight loss rate of fresh tea shoots reached 65%,70%,and 75%.The results showed that there were the similar sensory qualities in all tea samples.However,the freshness of the aroma decreased,and the sweetness of the taste increased in the white tea samples with Duiqing,compared with the Immobility and Bingshai.The quality of tea samples with the late Bingshai(4 to 8 sieves of work in process(WIP)merged into 1 sieve when the weight loss rate arrived at 70%)was slightly better than those with the early Bingshai(2 to 6 sieves of WIP merged into 1 sieve when the weight loss rate reached 65%).Furthermore,the best sensory qualities of the tea samples were produced from the thinnest Bingshai than Immobility.The best quality white tea sample was acquired with the thickest Duiqing(6 sieves of WIP merged into 1 basket)when treated for the same length of time(2 days)and different thicknesses(2 to 6 sieves of WIP merged into 1 bamboo basket:diameter(Φ)=46 cm,height(H)=72 cm)of Duiqing at the weight loss rate of 75%.Additionally,the WIP was preferred for the shortest duration(2 days),if treated with a different length of time(2 to 6 days)at such thickness of Duiqing.Although no regular changes were seen in the contents of catechins,alkaloids,and the main free amino acids among different treatments,the levels of proline(sweet)and some floral fruit components(phenylethanol,nerol,and geraniol)were significantly reduced in the white tea samples from the Duiqing process group,compared with the Immobility/Bingshai process group.The biochemical pattern recognition showed that all white tea sampl

关 键 词：工艺 品质控制 白茶 萎凋 摊青 

分 类 号：TS272.7[农业科学—茶叶生产加工]