轻揉捻条件下‘皖茶4号’红茶滋味品质 及非挥发性物质变化

Changes of Taste Quality and Non-volatile Compounds of 'Wan Cha 4' Black Tea under Light Rolling

摘要:

为探究轻揉捻工艺（揉捻25、35和45 min）红茶与正常揉捻（揉捻70 min，CK）红茶的滋味品质差异，以黄山地区‘皖茶4号’品种所制红茶为研究对象，通过感官审评、高效液相色谱仪和超高效液相色谱-四极杆-静电场轨道阱-质谱仪，结合偏最小二乘判别分析法，对4组红茶的滋味品质和非挥发性成分进行比较分析。结果显示，揉捻25 min的红茶样品滋味爽口特征明显且甜度高，苦涩度和醇厚度略低。不同揉捻程度红茶的非挥发性物质存在差异，筛选出咖啡碱、没食子儿茶素、没食子酸、奎宁酸、顺-5-p-对香豆酰奎宁酸等18种关键差异物质（VIP值>1且P<0.05）。可溶性糖含量在样品间未达到显著性差异（P>0.05），但其在揉捻25 min样品中最高，约为45.44 mg·g-1。茶黄素-3-没食子酸酯随揉捻时间增加，其含量呈降低趋势，在揉捻25 min样品中的含量高于CK红茶10.74%。咖啡碱在CK红茶中的含量为26.98 mg·g-1，显著高于25和35 min揉捻样品（25.18和25.27 mg·g-1）；奎宁酸和顺-5-p-对香豆酰奎宁酸在CK中的含量比揉捻25 min红茶低4.28%和10.29%。本研究结果为轻揉捻工艺红茶的技术应用提供了理论依据。

Abstract:

o investigate the differences in taste quality between light-rolling (25, 35, and 45 min) and conventional rolling (70 min, CK), black teas produced from the 'Wancha No.4' cultivar in the Huangshan region were conducted. The non-volatile profile of four types of black tea was analyzed by high-performance liquid chromatography (HPLC) and ultra-performance liquid chromatography coupled with a quadrupole-orbitrap mass spectrometry (UPLC-Q-Exactive-MS). Sensory evaluation and partial least squares discriminant analysis were also employed to verify tea quality and differential metabolites. The results showed that the 25-min rolling sample exhibits a notably refreshing mouthfeel and enhanced sweetness, accompanied by slightly reduced bitterness and thickness. Nineteen key differential metabolites were identified based on variable importance in projection (VIP) > 1 and statistical significance (P<0.05), including caffeine, theanine, epigallocatechin, gallic acid, quinic acid, cis-5-p-coumaroylquinic acid, and others. Although total soluble sugar content did not differ significantly among the treatments (P>0.05), it reached its highest level in the 25-min rolled sample (approximately 45.44 mg·g?1). Theaflavin-3-gallate exhibited a decreasing trend with prolonged rolling time, with a 10.74% higher concentration in the 25-min rolled tea compared to the CK. Caffeine content in the CK sample (26.98 mg·g?1) was significantly higher than in the 25-min and 35-min rolled samples (25.18 and 25.27 mg·g?1, respectively). In contrast, quinic acid and cis-5-p-coumaroylquinic acid levels in the CK were 4.28% and 10.29% lower, respectively, than in the 25-min rolled tea. These findings provide a theoretical foundation for the optimization and application of light-rolling technology in black tea processing.