主要水质因子对清香型黄山毛峰茶挥发性成分的影响

Effect of Main Water Quality Factors on Volatile Components of Huangshan Maofeng Tea with Faint Scent

利用顶空固相微萃取与气相色谱质谱联用技术分析主要水质因子对清香型黄山毛峰茶冲泡过程中的挥发性成分的影响;结合相关性与香气特征贡献度分析,分析清香型绿茶的香气骨架,明确水质对清香型绿茶挥发性成分的影响。研究结果表明:从香气特征贡献度来分析,7个主要组分的贡献率最大,其相对含量占总峰面积的33.36%,香气贡献高达96%,其中芳樟醇(76%)和二甲硫(10%)等对黄山毛峰的整体香气贡献最大,β-紫罗酮、己酸顺-3-己烯酯、庚醛、壬醛和癸醛之和也达10%。从感官评分看,影响黄山毛峰茶香气的因素依次为Ca^(2+)>p H>Mg^(2+)。从香气组分来分析,钙离子对二甲硫、辛醛和β-紫罗酮等有较明显的抑制作用,而对芳樟醇等有促进作用;当p H值低于5时利于壬醛、芳樟醇等组分挥发,当p H 5.5~6时利于二甲硫等组分的挥发;镁离子对这些香气组分影响较小。

Gas chromatography-mass spectrometry（GC-MS） combined withheadspace solid phase microextraction（HSSPME） has been successfully applied to analyze change of volatile componentsin Huangshan Maofeng tea with faint scent brewed by main water quality factors. In combination with analysis of correlation and aroma character impact（ACI）, the backbone components of green tea with faint scent was analyzed, and effect of water quality on volatile components of green tea was preliminarily known. The analysis of ACI showed that 7 major componentscontributed the most. The relative content of them was only 33.36% of the total peak areas, but the ACI reached up to 96%.Among them, linalool（76%）and dimethyl sulfide（10%） contributed the most to Huangshan Maofeng tea aroma, the sum of β-ionone, cis-3-hexenyl hexanoate, heptanal, nonanal and decanal reached 10%. The results of sensory scores showed that the aroma of Huangshan Maofeng tea was influenced by several factors, with descending order of Ca^2＋〉pH〉 Mg^2＋）; the analysis of volatile components showed that Ca^2＋ had obvious inhibitory effect on dimethyl sulfide, octanal and β-ionone, while promotive actions to linalool etc. It was found that pH lower than 5was advantageous to the production ofnonanal and linalool, and pH 5.5-6 was good for volatilization of dimethyl sulfide etc, while Mg^2＋ had little effect on these volatile components.