不同季节保靖黄金茶1号工夫红茶挥发性成分的HS-SPME-GC-MS分析

HS-SPME-GC-MS Analysis of Volatile Components of Congou Black Tea Processed from Baojing Huangjincha 1 from Different Harvesting Seasons

为研究不同季节湖南保靖黄金茶1号工夫红茶的香气品质特点,以春、夏和秋季保靖黄金茶1号一芽一叶为原料分别加工成工夫红茶样品,采用顶空固相微萃取结合气相色谱-质谱联用对3个季节工夫红茶的挥发性成分进行分析,结合感官审评考察不同季节对保靖黄金茶1号工夫红茶挥发性成分的影响。结果表明,3个季节工夫红茶香气均以甜香为主要特征,具体表现为春茶甜香纯正,夏茶甜香尚高,秋茶甜香带花香,秋茶香气指数最高,香气品质最好,夏、春茶次之,与感官审评结果一致。3个季节工夫红茶样品检出并鉴定到80种香气成分,其中春、夏和秋季红茶样品中分别检测出51、63种和66种香气成分,共有组分40种,主要以醇类、醛类、碳氢化合物、酯类和酮类物质为主;基于不同季节工夫红茶香气成分的含量作主成分分析(拟合参数为R2 X=0.941,Q2=0.825)并建立偏最小二乘-判别分析模型(拟合参数为R2 X=0.972,R2 Y=0.994,Q2=0.982)可有效区分春、夏和秋季的工夫红茶样品,不同季节工夫红茶的标志差异性化合物有13种,分别为水杨酸甲酯、苯甲醛、月桂烯、2,6-二甲基-3,7-辛二烯-2,6-二醇、1-乙基-2-甲酰吡咯、藏红花醛、反-橙叔醇、苯乙烯、2-辛烯-1-醛、反-2-癸烯醛、苯乙醇、反-芳樟醇氧化物(吡喃型)、反-2-壬烯醛。

In order to evaluate the aroma characteristics of Congou black tea from different harvesting seasons,Congou black tea were processed from one bud with one leaf from the cultivar Baojing Huangjincha 1 harvested in spring,summer and autumn and were analyzed for their volatile components by using headspace solid-phase microextraction(HS-SPME)combined with gas chromatography-mass spectrometry(HS-SPME-GC-MS).Meanwhile,sensory evaluation was conducted to investigate the effects of different harvesting seasons on the volatile aroma characteristics of Congou black tea.The results showed that the aroma of Congou black tea was mainly characterized as sweet and fragrant for all three seasons,specifically pure sweet aroma for spring tea,strong sweet aroma for summer tea,and sweet and flowery aroma for autumn tea.In addition,the flavor index(FI)of autumn tea was the highest and its aroma quality was the best,followed by summer and spring teas.This was consistent with the results of sensory evaluation.A total of 80 aroma components were detected and identified in the three samples,and 51,63 and 66 in spring,summer and autumn teas respectively.In total,40 aroma components were common to these samples mainly including alcohols,aldehydes,hydrocarbons,esters and ketones.The contents of aroma components in Congou black tea were analyzed by principal component analysis(R2X=0.941,Q2=0.825),and we further established a partial least squares-discriminant analysis model(R2 X=0.972,R2 Y=0.994,and Q2=0.982)to effectively distinguish the three tea samples.There were 13 landmark compounds that differed among these samples,including methyl salicylate,benzaldehyde,myrcene,3,7-octad iene-2,6-diol,2,6-dimethyl,1-ethyl-1H-pyrrole-2-carbaldehyde,safranal,(E)-nerolidol,styrene,2-octen-1-al,trans-2-decenal,phenylethyl alcohol,2-[(2S,5S)-5-ethenyl-5-methyltetrahydrofuran-2-yl]propan-2-ol-2H-pyran,and(E)-2-nonenal.