普洱散茶特征风味成分及抗氧化活性研究 - yzxzcom.doc

普洱散茶特征风味成分及抗氧化活性研究 陈梅春，潘志针陈峥，史怀，朱育菁，刘波*， 福建省农业科学院农业生物资源研究所，福建 福州350003 摘 要：以醛类、酮类、酯类及其它类化合物为辅。采用清除1，1-二苯基苦基苯肼（DPPH·）自由基的方法评价不同溶剂提取普洱散茶浸出物的抗氧化活性，结果表明普洱散茶沸水提取物的茶多酚含量为41.91mg/g，其DPPH·自由基清除能力最强，IC50=124.2mg/L；70%甲醇提取物的DPPH·自由基清除能力最弱，IC50=140.0mg/L。 关键词： 1，1-二苯基苦基苯肼 中图分类号： Analysis on Characteristic Components and antioxidant activities of Aged Pu-erh Tea CHEN Mei-chun, PAN Zhi-zhen, CHEN Zhen, SHI Huai, ZHUYu-jin, LIU Bo, Agricultural Bioresources Research Institute，Fujian Academy of Agricultural Sciences，Fuzhou，350003, China Abstract: Volatile compound of aged Pu-erh tea was analyzed by solid-phase micro-extraction (SPME) combined with gas chromatography-mass spectrometry (GC-MS). Results showed that a total of 57 volatile compounds were identified by matching EI mass spectra and retention indices with the literature data. Hydrocarbons, Alcohols, methoxy-phenolic and terpenes were four major aromatic groups characterized. The Pu-erh tea was extracted with four types of solvents and was studied for the inhibition of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH?). The boiling water extracts exhibited the strongest free radical scavenging activity than other three solvents with IC50values of 124.2mg/L, and the total phenolic content of which was 41.91 milligrams of gallic acid equivalent per gram of dried weight (mg/g). Whiles, the 70%methanol showed the lowest free radical scavenging activity with IC50 value of 140.0mg/L. Keywords: Pu-erh tea, flavor compounds, SPME, GC-MS, DPPH· 1.引言–5]。因此，从自然界中寻找自由基清除剂成为研究关注的热点。普洱茶具有抗氧化活性，主要归因于其特异的多酚类物质[6–8]。目前，国内外用于评价抗氧化能力的方法很多，如硫氰酸盐(thiocyanate)法、硫代巴比妥酸(thiobarbituricacid, TBA)法、电子自旋共振光谱法、1, 1-二苯基苦基苯肼(diphenylpicrylhydrazyl, DPPH)法等[9]。DPPH检测法是通过DPPH分子中1个稳定的自由基与抗氧化剂提供的1个电子配对结合,使DPPH的特征紫色消失，该方法具有快速、简便、灵敏的优点，因此可用于普洱茶抗氧化剂清除自由基能力的快速评价。本文采用固相微萃取与气相色谱-质谱（SPME/GC-MS）联用法对陈年普洱散茶的香气成分进行分析，通过测定DPPH自由基清除能力来考察普洱散茶的抗氧化活性，为普洱茶特征风味成分和保健功效的研究奠定基础。 2.材料与方法 仪器与试剂 气相色谱-质谱联用仪：Agilent 7890A/5975C。色谱柱：HP5-MS。萃取装置：SPME手动进样手柄、萃取头（30/50 μm PDMS/DVB/CAR）、顶空瓶