基于广泛靶向代谢组学的乌龙茶加工过程中差异代谢物分析

Analysis on Differential Metabolites of the Samples from Oolong Tea Production Based on Widely-Targeted Metabonomic Approach

为探寻乌龙茶加工过程中不同工序样品的特征性代谢物,采用液相色谱分析-电喷雾-串联质谱对乌龙茶样品进行广泛靶向代谢物检测。结果表明:在总计8道工序中鉴定出共有代谢物622种,主要包含糖类、氨基酸、黄酮、花青素类等物质。根据其在加工工序中的变化趋势,可将这些代谢物分为4种类型。代谢途径富集分析表明以氨基酸合成、淀粉与蔗糖代谢、类黄酮生物合成等途径占据主导地位。通过连续工艺比较,筛选出7种共有差异代谢物质,分别是14,15-脱氢还阳参油酸、3-甲基黄嘌呤、7-甲基黄嘌呤、葡萄糖-6-磷酸、枸橘苷、麦黄酮、牡荆素-2-O-鼠李糖苷。这些途径中代谢物种类和含量的变化,对乌龙茶风味的形成具有重要影响,为后续乌龙茶加工工艺改进提供理论基础。

This study aimed to explore the metabolites characteristics of oolong tea samples from consecutive production process.The abundance of metabolites in the samples was determined by using a liquid chromatography electrospray ionization tandem mass spectrum system.As a result,a total of 622 metabolites were identified and quantified in all eight samples,including carbohydrates,amino acids,flavonoids,anthocyanins and other substances.The metabolites could be divided into four types according to theirs changing trend.Additionally,the pathway enrichment analysis showed that biosynthesis of amino acids,starch and sucrose metabolism as well as flavonoid biosynthesis were the predominant pathways during the oolong tea production process,there were 7 metabolites were screened out by paired-comparison,namely 14,15-dehydrocrepenynic acid,3-methylxanthine,7-methylxanthine,glucose 6-phosphate,poncirin,tricin,vitexin 2-O-rhamnoside.These metabolites involved in these pathways mainly contributed to the formation of tea flavor,providing a novel approach to elucidate oolong tea flavor formation mechanisms.