基于代谢组学分析两种萎凋方式对白茶萎凋过程代谢物与品质的影响

基于代谢组学技术，比较室内自然萎凋和空气能萎凋两种萎凋工艺对白茶萎凋过程代谢物与品质的影响。结果表明，不同代谢物对2种萎凋工艺的响应存在差异，体现三种变化规律：第一类代谢物受萎凋工艺影响小，如咖啡碱、表没食子儿茶素和2'-羟基二氢大豆素等；第二类代谢物含量变化速率在空气能萎凋时加快，但其最终含量受影响小，如表没食子儿茶素没食子酸酯、聚酯型儿茶素A和木麻黄素等；第三类代谢物则受萎凋时间影响大，如茶没食子素与奎宁酸等。两种萎凋工艺对白茶品质影响存在差异，自然萎凋下黄酮(醇)糖苷类、儿茶素聚合体等含量更高，这些物质多在萎凋中后期含量提升；空气能萎凋下酚酸、茶氨酸含量更高，这些物质在自然萎凋后期含量大幅下降。萎凋时长是两种萎凋工艺导致代谢物含量差异的重要因素。

Effects of Two Withering Methods on Metabolites and Quality during Withering Process of White Tea Based

Based on metabolomics technology, the effects of different withering technologies on the metabolites and quality of white tea withering were compared. The results showed that the response of different metabolites to the two withering processes was different, reflecting three kinds of changes: the first type of metabolites was less affected by the withering process, such as caffeine, EGC and 2'-hydroxydihydrodaidzein; the second type of metabolites showed accelerated conversion rate under air conditioner withering, but had little effect on the final dry tea content, such as EGCG, theasinensin A, and strictinin; and the third type of metabolites was greatly affected by the withering time, such as theogallin and quinic acid. There were different effects on the quality of white tea by two withering processes. Under natural withering the contents of flavonoids (alcohols), glycosides, catechin polymers, etc. were higher, and the contents of these substances increased in the middle and late stages of withering; under air conditioner withering the content of phenolic acid and theanine was higher, and these substances decreased sharply in the latter stage of natural withering. The withering time was an important factor for the difference in the content of metabolites between the two withering processes.