为了解不同品牌普洱茶香气成分的特点和差异性,本研究采用电子鼻(electronic nose, E-nose)和顶空固相微萃取(headspace solid phase microextraction, HS-SPME)结合气相色谱-质谱联用(gas chromatography-mass spectrometry, GC-MS)对3个品牌普洱茶香气成分进行分析和鉴定。结果表明,E-nose能够较好区分3个品牌的普洱茶,主成分分析显示不同品牌样品间差异明显,区分度良好。进一步采用HS-SPME-GC-MS对普洱茶香气构成进行分析,结果共检测出74种化合物,共有成分38种,其中大益普洱茶、老同志普洱茶和澜沧古茶分别检测出66、53和48种,主要包括:醛类、醇类、酮类、甲氧基苯类化合物等物质,且物质组成和含量差异显著,主要差异性物质包括2-羟基-6-甲基苯甲醛、藏红花醛、芳樟醇氧化物、4-萜烯醇、甲基庚烯酮、(E,E)-3,5-辛二烯-2-酮、1,4-二甲氧基苯、1-甲氧基-4-(1-丙烯基)-苯、邻异丙基甲苯、α-松油烯、邻苯二甲酸二甲酯、咖啡因。香气活性值(odour active values, OAV)分析表明造成香气差异的物质主要是(E)-2-辛烯醛、(E,E)-2,4-壬二烯醛、壬醛、α-紫罗兰酮、香叶基丙酮。
In order to understand the differences in aroma components of different brands of Pu-erh tea, volatile compounds and characteristic aroma of three kinds of Pu-erh tea were analyzed and identified by electronic nose (E-nose) and headspace solid phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS). The results showed that E-nose could distinguish three brands of products well. The principal component analysis showed that the differences between different brands were obvious with good distinction. Further HS-SPME-GC-MS analysis showed that seventy-four compounds in total were identified from three brands of Pu-erh tea. Among them, thirty-eight compounds were shared between all brands of Pu-erh tea tested. Sixty-six, fifty-three, and forty-eight volatile compounds were identified in Dayi Pu-erh tea, Lao Tongzhi Pu-erh tea, and Lancang ancient tea, respectively. The main compounds were aldehydes, alcohols, ketones, and methoxy-phenolic compounds etc. Differences in varieties and contents of volatile compounds between different brands of Pu-erh tea were significant. The main compounds that showed differences including 2-hydroxy-6-methoxy-benzaldehyde, safranal,linalool oxide, terpinen-4-ol, 6-methyl-5-hepten-2-one, (E,E)-3,5-octadien-2-one, 1,4-dimethoxy-benzene, 1-methoxy-4-(1-propenyl)-benzene, 1-methyl-2-(1-methylethyl)-benzene, α-terpinene, dimethyl phthalate, and caffeine. Analysis of odour active values showed that different odors were caused by (E)-2-octenal, (E,E)-2,4-nonadienal, nonanal, α-ionone, and geranyl acetone.
[1] LV S D, WU Y S, WEI J F, et al. Application of gas chromatography-mass spectrometry and chemometrics methods for assessing volatile profiles of Pu-erh tea with different processing methods and ageing years[J]. RSC Advances, 2015,5(107):87 806-87 817.
[2] 李向波,刘顺航,贾黎晖,等. 普洱茶感官品质分析及风味轮构建[J]. 中国茶叶, 2017, 39 (11): 32-34.
[3] DU L P, LI J X, LI W, et al. Characterization of volatile compounds of Pu-erh tea using solid-phase microextraction and simultaneous distillation-extraction coupled with gas chromatography-mass spectrometry[J]. Food Research International, 2014, 57(1): 61-70.
[4] 吕海鹏,钟秋生,林智. 陈香普洱茶的香气成分研究[J]. 茶叶科学, 2009, 29 (3):219-224.
[5] XU Y Q, WANG C, LI C W, et al. Characterization of aroma-active compounds of Pu-erh tea by headspace solid-phase microextraction (HS-SPME) and simultaneous distillation-extraction (SDE) coupled with GC-olfactometry and GC-MS[J]. Food Analytical Methods,2016, 9(5): 1 188-1 198.
[6] LV H P, ZHONG Q S, LIN Z, et al. Aroma characterisation of Pu-erh tea using headspace-solid phase microextraction combined with GC/MS and GC-olfactometry[J]. Food Chemistry, 2012, 130(4): 1 074-1 081.
[7] YANG Z Y, DONG F, SHIMIZU K, et al. Identification of coumarin-enriched Japanese green teas and their particular flavor using electronic nose[J]. Journal of Food Engineering, 2009, 92(3): 312-316.
[8] 刘远方,李阳,梁飞,等. 绿茶香气的电子鼻分析方法研究[J]. 食品科技, 2012, 37(1): 58-62.
[9] WILSON A D, BAIETTO M. Applications and advances in electronic-nose technologies[J]. Sensor, 2009, 9(7): 5 099-5 148.
[10] QIN Z H, PANG X L, CHEN D, et al. Evaluation of Chinese tea by the electronic nose and gas chromatography-mass spectrometry: Correlation with sensory properties and classification according to grade level [J]. Food Research International, 2013,53(2): 864-874.
[11] YE J, WANG W G, HOU C T, et al. Differentiation of two types of pu-erh teas by using an electronic nose and ultrasound-assisted extraction-dispersive liquid-liquid microextraction-gas chromatography-mass spectrometry[J]. Analytical Methods, 2016, 8(3): 593-604.
[12] HANSEN T, PETERSEN M, BYRNE D. Sensory based quality control utilising an electronic nose and GC-MS analyses to predict end-product quality from raw materials [J]. Meat Science, 2005, 69(4): 621-634.
[13] SCHUH C,SCHIEBERLE P. Characterization of the key aroma compounds in the beverage prepared from Darjeeling black tea: quantitative differences between tea leaves and infusion [J]. Journal of Agricultural and Food Chemistry, 2006, 54(3): 916-924.
[14] WANG J, WEI Z B. The classification and prediction of green teas by electrochemical response data extraction and fusion approaches based on the combination of e-nose and e-tongue[J]. RSC Advances, 2015, 5(129): 106 959-106 970.
[15] 王鹏杰,张丹丹,邱晓红,等. 基于GC-MS和电子鼻技术的武夷岩茶香气分析[J]. 福建茶叶, 2017, 39(1): 16-18.
[16] 舒畅,佘远斌,肖作兵,等. 新、陈龙井茶关键香气成分的SPME/GC-MS/GC-O/OAV研究[J]. 食品工业, 2016(9): 279-285.
[17] 曾亮,王杰,柳岩,等. 小种红茶与工夫红茶品质特性的比较分析[J]. 食品科学, 2016, 37(20): 51-56.
[18] 宁井铭,张正竹,宛晓春. 基于气相色谱技术的普洱熟茶7572挥发性物质指纹图谱建立及应用[J]. 食品与发酵工业, 2016,42(10): 176-183.
[19] 吕海鹏,林智,张悦,等. 不同等级普洱茶的化学成分及抗氧化活性比较[J]. 茶叶科学, 2013, 33(4): 386-395.
[20] DU L P, WANG C, LI J X, et al. Optimization of headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry for detecting methoxyphenolic compounds in Pu-erh tea[J]. Journal of Agricultural and Food Chemistry, 2013, 61(3): 561-568.
[21] PENZA M, CASSANO G, TORTORELLA F, et al. Classification of food, beverages and perfumes by WO 3 thin-film sensors array and pattern recognition techniques[J]. Sensors and Actuators B Chemical, 2001, 73(1): 76-87.
[22] MCKELLAR R C, RUPASINGHE H V, LU X, et al. The electronic nose as a tool for the classification of fruit and grape wines from different Ontario wineries[J]. Journal of the Science of Food and Agriculture, 2010, 85(14): 2 391-2 396.
[23] 刘晔,葛丽琴,王远兴. 庐山云雾茶挥发性成分主成分分析及产地判别[J]. 食品科学, 2017, 38(24): 60-67.
[24] WANG C, ZHANG C X, KONG Y W, et al. A comparative study of volatile components in Dianhong teas from fresh leaves of four tea cultivars by using chromatography-mass spectrometry, multivariate data analysis, and descriptive sensory analysis[J]. Food Research International, 2017, 100(1): 267-275.
[25] WANG C, LV S D, WU Y S, et al. Oolong tea made from tea plants from different locations in Yunnan and Fujian, China showed similar aroma but different taste characteristics[J]. Springerplus, 2016, 5(1): 576-590.
[26] 王秋霜,吴华玲,凌彩金,等. 普洱茶理化品质及特征“陈香”物质基础研究[J]. 食品工业科技, 2017, 38(5):308-314.
[27] ALASALVAR C, TOPAL B, SERPEN A, et al. Flavor characteristics of seven grades of black tea produced in Turkey[J]. Journal of Agricultural and Food Chemistry, 2012, 60(25): 6 323-6 332.
[28] BYJU K, ANURADHA V, ROSMINE E, et al. Chemical characterization of the lipophilic extract of Hydrilla verticillata: a widely spread aquatic weed[J]. Plant Biochem Biotechnol, 2013, 22(3): 304-311.
[29] 颜鸿飞,王美玲,白秀芝,等. 湖南茯砖茶香气成分的SPME-GC-TOF-MS分析[J]. 食品科学, 2014, 35 (22): 176-180.
[30] LV S D, WU Y S, ZHOU J S, et al. The study of fingerprint characteristics of dayi Pu-erh tea using a fully automatic HS-SPME/GC-MS and combined chemometrics method[J]. Plos One, 2014, 9(12): e116 428.
[31] 张峻松,张常记,郑峰洋,等. 超高压处理对普洱生茶香味成分的影响研究[J]. 茶叶科学, 2008, 28(4): 267-272.
