摘要
为探究渥堆进程中影响黟县黑茶滋味品质变化的关键节点,本研究通过感官评价、氦基酸分析仪、液相色谱及液相色谱质谱联用仪,分析了不同渥堆时间下(0、3、6、9、12、15和18h)其滋味品质及代谢物的变化.结果表明,渥堆9h后茶汤苦味开始降低、收敛性和厚度增加、陈醇风味凸显.儿茶素类物质总量在渥堆期间显著降低,而没食子酸含量则显著增加;咖啡碱含量在渥堆18h后降低了 14.7％;游离氨基酸总量在渥堆后期(15～18h)呈现上升趋势;黄酮醇及单糖苷的黄酮苷类物质含量在渥堆中期(9～12h)显著增加(P＜0.05);双糖苷的黄酮苷类物质含量则在渥堆中后期呈上升趋势.关键滋味物质分析显示(VIP＞1,DOT＞1),杨梅素-3-O-半乳糖苷、紫云英苷、异槲皮苷、槲皮素-3-O-芸香糖苷、表没食子儿茶素、表儿茶素、表没食子儿茶素没食子酸酯及咖啡碱是影响黟县黑茶品质变化的重要呈味物质,其中,前三种糖苷类物质在渥堆9～12h含量显著增高;表没食子儿茶素、表儿茶素在9～12h期间含量显著降低;表没食子儿茶素没食子酸酯、咖啡碱在渥堆后呈现显著降低;槲皮素-3-O-芸香糖苷在渥堆中期(9～12h)显著下降,在渥堆15 h后显著增加,是渥堆后期茶汤涩感增加的重要因子.本研究结果为后续黟县黑茶渥堆工艺优化及探究其滋味品质形成机制提供了重要理论参考.
Abstract
In order to investigate the key nodes affecting the changes of Yixian dark tea flavor and quality during the Pile fermentation,in this study,the sensory quality and non-volatile profiles of Yixian dark tea samples at different pile fermentation periods(0,3,6,9,12,15,18 h)were investigated by sensory evaluation,amino acids analyzer,liquid chromatography and liquid chromatography mass spectrometry.The results showed that the intensity of bitterness in dark tea infusions declined after 9 h of pile fermentation,along with the increasing intensities of astringency,thickness and stale-mellow.Total catechins showed a significant decrease in concentrations during pile fermentation.In contrast,the concentration of gallic acid increased.Concentration of caffeine reduced by 14.7％compared to the original concentration after 18 h of pile fermentation.Total amino acids concentration showed an increasing tendency in the later period of pile fermentation.Concentrations of flavonoids and its mono-glycosides increased after 9～12 hours,while its di-glycosides showed an increasing tendency after 12 hours of pile fermentation.The analysis of key taste substances(VIP＞1,DOT＞1)showed that myricetin-3-O-galactoside,astragalin,isoquercitrin,quercetin-3-O-rutinose,epigallocatechin,epicatechin,epigallocatechin gallate,and caffeine were the most important flavor presenting substances affecting the quality changes of Yixian dark tea.Among them,the content of the first three glycosides increased significantly from 9～12 hours of stacking;The contents of epigallocatechin and epicatechin were significantly reduced during 9～12 hours.Epigallocatechin gallate and caffeine showed a significant decrease after pile fermentation;Quercetin-3-O-rutinoside decreased significantly in the middle stage(9～12 hours)and increased significantly after 15 hours.It was an important factor in the increase of astringency of tea broth in the late stage of pile fermentation.This study give a theoretical basis for improving the tea processing of Yixian dark tea and understanding the formation mechanism of its key flavor.
基金项目
黄山市科技计划项目(2022KN-07)
黟科科技助力乡村振兴计划项目(2021KN-03)
国家现代农业产业技术体系建设专项(CARS-19)
维普
万方数据