香气对红茶的品质起着举足轻重的作用。然而,红茶的可接受性受到由于不适当的加工控制而产生的绿色异味(GOF)的极大限制。在这项研究中,volatolomics研究了导致GOF的关键气味,深入了解了它们的动态变化和形成途径。在枯萎阶段观察到挥发性代谢物的显着变化。共有14种关键气味剂被确定为GOF的贡献者,包括2-甲基丙醛,3-甲基丁醛,1-己醇,非肛门,(E,E)-2,4-庚二烯醛,苯甲醛,芳樟醇,(E,E)-3,5-辛二烯-2-酮,β-环二尖瓣,苯乙醛,(E,E)-2,4-壬烯,水杨酸甲酯,香叶醇,和β-紫罗兰酮.其中,(E,E)-2,4-庚二烯醛(OAV=3913),以脂肪为特征,绿色,油腻的香气,被认为是导致GOF的最重要因素。此外,发现脂质降解是GOF的主要代谢途径。本研究为红茶的异味控制和品质改良提供了理论依据。
Aroma plays a pivotal role in the quality of black tea. However, the acceptability of black tea is greatly limited by the green off-flavor (GOF) resulting from the inappropriate processing control. In this study, the key odorants causing GOF were investigated by volatolomics, and their dynamic changes and formation pathways were in-depth understood. Significant alterations in volatile metabolites were observed in the withering stage. A total of 14 key odorants were identified as contributors to GOF, including 2-methylpropanal, 3-methylbutanal, 1-hexanol, nonanal, (E, E)-2,4-heptadienal, benzaldehyde, linalool, (E, E)-3,5-octadiene-2-one, β-cyclocitral, phenylacetaldehyde, (E, E)-2,4-nonadienal, methyl salicylate, geraniol, and β-ionone. Among them, (E, E)-2,4-heptadienal (OAV = 3913), characterized by fatty, green, and oily aromas, was considered to be the most important contributor causing GOF. Moreover, it was found that lipid degradation served as the primary metabolic pathway for GOF. This study provides a theoretical foundation for off-flavor control and quality improvement of black tea.