基于HS-SPME-GC-MS分析桂北大叶种红茶呈香挥发性物质

Analysis of Aroma Volatile Compounds in Black Tea Produced from the Large-leaf Variety in Northern Guangxi Based on HS-SPME-GC-MS

摘要:

【目的】探究桂北大叶种红茶的风味特征与挥发性物质差异，解析品种香气形成的物质基础。【方法】通过感官审评、生化指标测定、顶空固相微萃取-气质联用（HS-SPME-GC-MS）技术以及香气活性值（OAV）分析等方法，结合化学计量学分析，对桂北大叶种红茶的风味特征与挥发性物质进行了深入分析。【结果】桂北大叶种香气属性高度相似，花果香最为显著。桂北大叶种红茶中共鉴定出88种挥发性物质，包括醇类、酯类、醛类、酮类、酸类等，其中酯类、醛类、酮类物质质量浓度较高，利用化学计量学分析，以变量重要性投影（VIP）>1且OAV>1.0为标准，共筛选出6种共有关键香气成分，其中芳樟醇、香叶醇和α-月桂烯是构成桂北大叶种红茶果香带花香的特征香气物质，壬醛是呈现馥郁花香的特征香气物质，水杨酸甲酯是呈现薄荷香的特征香气物质，β-紫罗兰酮是呈现浓郁清花香和奶香的特征香气物质。这些成分被认为是桂北大叶种红茶地域香的关键形成因子。【结论】桂北大叶种红茶的香气以花果香为显著特征，其关键香气物质为芳樟醇、香叶醇、α-月桂烯、壬醛、水杨酸甲酯及β-紫罗兰酮，这些物质协同构成了该茶种独特的地域香特征。

Abstract:

[Objective]This study explores the unique flavor characteristics and volatile compounds of black tea produced from the large-leaf variety in northern Guangxi, aiming to reveal the material basis of aroma formation of this variety.[Method]Sensory evaluation, determination of biochemical parameters, headspace-solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS), and odor activity value (OAV) analysis were performed in combination with chemometrics analysis to analyze the flavor characteristics and volatile compounds of the black tea.[Result]The black tea samples produced from the large-leaf variety in northern Guangxi had similar aroma properties and were characterized by distinct floral and fruity aromas. A total of 88 volatile compounds including alcohols, esters, aldehydes, ketones, and acids were identified from the black tea samples. The mass concentrations of esters, aldehydes, and ketones were higher. Six key aroma components were selected by the chemometrics analysis, with the criteria of variable importance in the projection (VIP)>1 and OAV>1.0. Among them, linalool, geraniol, and α-myrcene were the characteristic aroma compounds conferring the floral and fruity aromas of the black tea. Nonanal, methyl salicylate, and β-ionone were the characteristic aroma compounds conferring the floral aroma, the mint aroma, and the strong floral and creamy aroma, respectively. These components were considered to be the key factors for the aroma formation of the black tea produced from the large-leaf variety in northern Guangxi.[Conclusion]The black tea produced from the large-leaf variety in northern Guangxi is characterized by floral and fruity aromas. The key aroma compounds are linalool, geraniol, α-myrcene, nonanal, methyl salicylate, and β-ionone, which together constitute the unique aroma characteristics of the black tea in this area.