不同萎凋方式和碰青工艺对红茶挥发性成分的影响

摘要

To determine the effects of withering measures and Peng-qing treatments on black tea aroma, tea volatile flavor compounds ( VFC) and these precursors were investigated by sensory evaluation, headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS), with Jinxuan as the materials. The results showed that changing the ways of withering or introducing Peng-qing treatments, the composition of body note did not change, but black tea aroma had alerted for variation of VFC contents. Two ways, fan withering and sun withering, had positive effects on the aroma differences between made teas. Dehumidifier withering and Peng-qing treatments could lead to the aroma much higher and richness. Alcohols were the main category in a total of forty-eight of VFC identified, accounting for 71.58%-74.19%. Anti-β-ocimene was the unique component. The precursors of VFC had showed the regular changes, sun withering could make phenylalanine, farnesyl diphosphate (FPP) and granyl geranyl pyrophosphate (GPP) degrade. While VFC were generated by unsaturated fatty acid degradation through fan and dehumidifying withering. Peng-qing treatments had played a positive role in the volatile components from the degradation of phenylalanines and carotenoids, which were negatively correlated with the static time. The researches provide a theoretical reference for using oolong tea varieties to make black tea.%为探明萎凋方式和碰青工艺对红茶香气形成的影响,以金萱为材料,采用顶空固相微萃取和气相色谱—质谱联用分析技术(HS-SPME-GC-MS)结合茶叶感官审评,研究红茶可挥发性成分和香气前体物的变化规律.结果表明,改变萎凋方式或引入碰青工艺对金萱红茶主要挥发性成分并没有很大作用,但可引起挥发性成分相对含量变化,导致茶叶香型发生改变.日光和鼓风萎凋对金萱红茶香型差异性有积极作用.抽湿萎凋和碰青工艺则增强香气的丰富度和持久性.鉴定的48种挥发性化合物中主要为醇类,占香气总量的71.58%~74.19%.反-β-罗勒烯是区别于其他红茶的主要成分之一.茶叶前体物产生的挥发性成分呈规律性变化,日光萎凋有利于苯丙氨酸和法呢基焦磷酸/牻牛儿基焦磷酸为前体的挥发性成分产生;鼓风和抽湿萎凋则以不饱和脂肪酸降解的挥发性成分为主.碰青工艺对来自苯丙氨酸和类胡萝卜素的挥发性成分有积极作用,但与静置时间成负相关.本研究结果为乌龙茶品种改制红茶提供理论参考.