State Key Laboratory of Tea Plant Biology and Utilization, Anhui Agricultural University, 130 Changjiang Ave W., Hefei, Anhui 230036, People's Republic of China.
International Joint Laboratory on Tea Chemistry and Health Effects, Anhui Agricultural University, 130 Changjiang Ave W., Hefei, Anhui 230036, People's Republic of China.
J Agric Food Chem. 2020 Sep 30;68(39):10815-10821. doi: 10.1021/acs.jafc.0c04208. Epub 2020 Sep 11.
β-Ionone is a carotenoid-derived flavor and fragrance compound with a complex fruity and woody scent, known for its violet aroma. Due to the low odor threshold, β-ionone dramatically affects the aroma and quality of tea. Previous studies have shown that β-ionone increases during tea withering; however, its formation and regulation during the withering process are far from being understood. As dehydration is the most important stress during the withering of the tea leaves, we isolated a dehydration-induced gene belonging to the subfamily of carotenoid cleavage dioxygenases called carotenoid cleavage dioxygenase 1a () from and expressed it in . The recombinant protein could generate volatile β-ionone and pseudoionone from carotenoids. was induced by dehydration stress, and its expression was related to the β-ionone accumulation during tea withering. Overall, this study elucidated that catalyzes the formation of β-ionone in and enhanced the understanding of the β-ionone formation under multiple stresses during the processing of tea.
β-紫罗兰酮是一种类胡萝卜素衍生的风味和香料化合物，具有复杂的果香和木香，因其紫罗兰香气而闻名。由于气味阈值低，β-紫罗兰酮极大地影响了茶的香气和质量。先前的研究表明，β-紫罗兰酮在萎凋过程中增加；然而，其形成和调节在萎凋过程中还远未被理解。由于脱水是茶叶萎凋过程中最重要的应激，我们从 中分离出一个属于类胡萝卜素双加氧酶亚家族的脱水诱导基因，称为类胡萝卜素双加氧酶 1a ()，并在 中表达。重组蛋白可以从类胡萝卜素中产生挥发性β-紫罗兰酮和假紫罗兰酮。 受脱水胁迫诱导，其表达与茶萎凋过程中β-紫罗兰酮的积累有关。总的来说，这项研究阐明了 在 中催化β-紫罗兰酮的形成，并增强了对茶叶加工过程中多种胁迫下β-紫罗兰酮形成的理解。
