云茶香1号不同萎凋工艺白茶的化学品质研究

Study on the chemical quality of white tea with different withering processes of Camellia sinensis vs Yunchaxiang 1

目的探究云茶香1号茶树品种不同萎凋处理白茶的品质特征及香气特征物质。方法以一芽二叶鲜叶(YC-R)为原料,采用自然萎凋(YC-T)和复式萎凋(YC-L)工艺加工白茶,进行感官审评,理化分析结合气相色谱-质谱法(gas chromatography-mass spectrometry, GC-MS)对白茶中的挥发性及非挥发性成分进行检测。通过挥发性物质代谢通路富集分析出的代谢途径注释物质,结合差异倍数前20的物质,揭示了两种白茶的风味特征物质。结果云茶香1号加工的白茶品质优质,YC-T的儿茶素、可溶性糖含量高, YC-L茶多酚、咖啡碱、氨基酸、黄酮含量高。两种白茶中共鉴定出挥发性物质234种, YC-T 229种, YC-L 226种,可分为12类,杂环类化合物最高;YC-T中具有果香的(E)-2-己酸丁酯和癸醛含量较高,YC-L中橙花醇、亚油酸甲酯、乙酸叶醇酯、亚麻酸、(E)-2-己酸丁酯、3-甲基苯甲醛、香叶酸、苯乙醇、3-甲基-1H-吲哚、α-松油醇、(-)-4-萜品醇、香叶醇、左旋-β蒎烯、苯乙醛、3,6-壬二烯醛较高,具有花香、果香、甜香、嫩香、香料香、蜜香、坚果香的香气表征。结论自然萎凋白茶有利于白茶外形叶底均匀性的固定,复式萎凋有利于白茶形成丰富的滋味和丰富白茶香气特征。

Objective To investigate the quality characteristics and aroma characteristic substances of white tea with different withering process of Camellia sinensis vs Yunchaxiang 1.Methods White tea was processed by natural withering(YC-T) and combined withering(YC-L) using one bud and two fresh leaves(YC-R) as raw material.Then,the sensory quality evaluation,physical and chemical composition,and gas chromatography-mass spectrometry(GC-MS) were used to test the variety components.Through the metabolic pathway enrichment analysis of metabolic pathway annotation substances,combined with the top 20 substances in terms of difference multiplicity,revealed the flavor characteristic substances of 2 kinds of white teas.Results High quality white tea produced with Camellia sinensis vsvs Yunchaxiang 1.YC-T was high in catechin and soluble sugar,and YC-L was high in polyphenols,caffeine,amino acids and flavonoids.A total of 234 kinds of volatile substances,including 229 kinds of YC-T and 226 kinds of YC-L,were identified in the 2 kinds of white teas,which could be classified into 12 categories,with the highest heterocyclic compounds;the content of(E)-2-butyl hexanoate and decanal in YC-T with fruity aroma were higher,and nerolidol,methyl linoleate,acetate leaf alcohol ester,nerolidol,linolenic acid,(E)-2-hexanoic acid butyl ester,3-methylbenzaldehyde,geranylic acid,phenylethyl alcohol,3-methyl-1 H-indole,α-terpineol,(-)-4-terpineol,geraniol,leuco-β-pinene,phenylethyl aldehyde,3,6-nonadienal,with aroma characterization of floral,fruity,sweet,tender,spicy,honey and nutty aromaswere higher than those in YC-L.Conclusion The natural withering of white tea is conducive to the fixation of the uniformity of the leaf base of white tea shape,and the compound withering is conducive to the formation of rich taste as well as the enrichment of the aroma characteristics of white tea.