Abstract:
Processing is the crucial factor for green tea aroma quality. In this study, the aroma dynamic changes throughout the manufacturing process of chestnut-like aroma green tea were investigated with gas chromatography electronic nose (GC-E-Nose), gas chromatography-ion mobility spectrometry (GC-IMS), and comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC × GC-TOFMS). GC-IMS identified 33 volatile compounds while GC × GC-TOFMS identified 211 volatile components. Drying exerted the greatest influence on the volatile components of chestnut-like aroma green tea, and promoted the generation of heterocyclic compounds and sulfur compounds which were commonly generated via the Maillard reaction during the roasting stage. A large number of heterocyclic compounds such as 1-methyl-1H-pyrrole, pyrrole, methylpyrazine, furfural, 2-ethyl-5-methylpyrazine, 1-ethyl-1H-pyrrole-2-carboxaldehyde, and 3-acetylpyrrole were newly formed during the drying process. This study also validated the suitability of GC-E-Nose combined with GC-IMS and GC × GC-TOFMS for tracking the changes in volatile components of green tea throughout the manufacturing process.
摘要:
加工是绿茶香气品质的关键因素。在这项研究中,利用气相色谱电子鼻(GC-E-Nose)研究了栗香绿茶整个生产过程中香气的动态变化,气相色谱-离子迁移谱(GC-IMS),和全面的二维气相色谱耦合飞行时间质谱(GC×GC-TOFMS)。GC-IMS鉴定出33种挥发性化合物,而GC×GC-TOFMS鉴定出211种挥发性成分。干燥对栗香绿茶的挥发性成分影响最大,并促进了在焙烧阶段通常通过美拉德反应产生的杂环化合物和硫化合物的产生。大量的杂环化合物,如1-甲基-1H-吡咯,吡咯,甲基吡嗪,糠醛,2-乙基-5-甲基吡嗪,1-乙基-1H-吡咯-2-甲醛,和3-乙酰吡咯在干燥过程中新形成。这项研究还验证了GC-E-Nose与GC-IMS和GC×GC-TOFMS结合用于跟踪整个制造过程中绿茶挥发性成分变化的适用性。