电子鼻联合气相色谱-质谱技术解析澜沧县不同晒青茶的香气指纹及地域差异

Aroma fingerprinting and geographical differentiation of sun-dried green teas from different regions of Lancang County by electronic nose coupled with gas chromatography-mass spectrometry

中文关键词:  晒青茶，香气成分，电子鼻，风味，气相色谱-质谱(GC-MS)，主成分分析(PCA)

英文关键词:sun-dried green tea  aroma compounds  electronic nose  flavor profile  gas chromatography-mass spectrometry  principal component analysis

中文摘要:

      目的 探究云南省澜沧县不同产区晒青茶的香气特征及地域差异, 并建立具有可解释性的香气指纹判别思路。方法 联合电子鼻(electronic nose, E-nose)与气相色谱-质谱技术(gas chromatography-mass spectrometry, GC-MS), 对澜沧县10个地区茶样的挥发性成分展开系统研究。结果 电子鼻主成分分析(principal component analysis, PCA)表明, 传感器W1W、W2W与W3S为PC1主要贡献, W1S、W2S等传感器对PC2香气贡献较大, 表明醇类、醛酮类、芳香族化合物以及甲基类物质在香气轮廓构建中起主导作用; 其中, 扎布(ZB)茶样明显偏离样本群, 可能是W1W、W2W与W3S等传感器较强响应密切相关。GC-MS检测中主要以醇、醛、酮类为主, 其中芳樟醇与β-紫罗酮为关键贡献香气成分。聚类结果显示, 东卡河(DKH)与邦坡大箐(BPDQ)形成独立分支, 表达其特殊的香气组分。不同产区呈现指示性挥发物组合: ZB产区茶样富含橙花醇和环己烯酮, 呈现“橙花-青草”香气; 小坝(XB)样品独有柏木脑和1,2,3-三甲氧基苯, 与其“清新青香-柔和木甜”的香气基调相关; 芒景(MJ)茶样中苯乙醛含量高, 可能贡献于其“蜂蜜熟果-清新柑橘木香”的复合蜜香; DKH茶样香气中芳樟醇含量高, 呈现“高扬花香-柑橘”香型; BPDQ茶样的香气以高含量1-辛烯-3-醇为主导, 呈现出“菌菇、湿木与熟果甜润”的底香。结论 电子鼻与GC-MS联合分析方法不仅实现了晒青茶香气特征的快速、有效区分及产区鉴别, 而且具有良好的可解释性。本研究为澜沧县晒青茶的品质评价、产地认证与地理标志保护提供了可靠的理化指标依据。

英文摘要:

      Objective To elucidate the aroma characteristics and regional differences of sun-dried green tea from different producing areas in Lancang County, Yunnan Province, and to establish an interpretable framework for aroma fingerprinting and geographical origin discrimination. Methods Volatile profiles of sun-dried green tea samples collected from 10 producing areas in Lancang County were systematically characterized by combining an electronic nose (E-nose) with gas chromatography-mass spectrometry (GC-MS). Results Principal component analysis (PCA) of E-nose responses showed that sensors W1W, W2W and W3S contributed predominantly to PC1, whereas sensors such as W1S and W2S contributed more to PC2, indicating that alcohols, aldehydes/ketones, aromatic compounds and methyl-related substances were major drivers shaping the overall aroma profile. The ZB samples deviated markedly from the main cluster, which was likely attributable to the stronger responses of sensors W1W, W2W and W3S. GC-MS profiling revealed that alcohols, aldehydes and ketones dominated the volatile composition, and linalool together with β-ionone were identified as key contributors to aroma differentiation. Hierarchical clustering further indicated that DKH and BPDQ formed independent branches, reflecting their distinctive volatile signatures. Region-discriminating marker sets were identified: ZB samples were enriched in nerol and 2-cyclohexen-1-one, corresponding to an “orange blossom-grassy” note; XB samples uniquely contained cedrol and 1,2,3-trimethoxybenzene, consistent with a “Fresh green notes to soft woody sweetness” tone; MJ samples showed elevated phenylacetaldehyde, potentially contributing to a compound honey-like aroma characterized by “honey-ripe fruit with fresh citrus-woody notes”; DKH samples exhibited high linalool levels, presenting a pronounced “floral-citrus” profile; and BPDQ samples were dominated by 1-octen-3-ol, featuring base notes reminiscent of “mushroom, wet wood and mellow sweet ripe fruit”. Conclusion The integrated E-nose and GC-MS strategy enables rapid and effective discrimination of aroma characteristics and producing areas of sun-dried green tea with good interpretability, providing reliable physicochemical evidence for quality evaluation, origin authentication and geographical indication protection of sun-dried green tea from Lancang County.