不同干燥方式对夏季绿茶香气品质的影响

为研究不同干燥方式对夏季绿茶香气品质的影响，采用顶空固相微萃取与气相色谱-质谱联用法（Gas Chromatography-mass Spectrometry，GC-MS），结合气味活度值（odor activity value，OAV），分析重庆地产绿茶香气成分的变化情况。结果表明:供试茶样共检测到120种香气，主要为醇类、酯类、烯类、脂肪烃类。与烘青比较，经晒青结合烘干后，重庆地产绿茶醇类种类增多，其中芳樟醇、反式氧化芳樟醇、4-萜烯醇、2-癸烯-1-醇、橙花叔醇等萜烯醇含量明显升高，醛类、酮类种类无明显变化，酯类种类差异明显，其他香气种类变化规律不一致。总体上60 ℃低温烘干能保留更多的挥发性成分，而相同的烘干温度下，挥发性成分总含量随晒青时间延长呈现先降后升的趋势。β-紫罗酮、月桂烯是各茶样共有的香气物质，各茶样β-紫罗酮的OAV值在351.4～595.7之间，对香气贡献最大，各茶样月桂烯的OAV值均>1，对茶叶香气贡献较大，故所有茶样均具有清甜香或甜香，这与感官审评结果一致。但部分特殊的花果香或是坚果香并未在审评中表现出来，可能是被晒青产生的日晒味所掩盖。

Effects of Drying Methods on Volatile Components of Summer Green Tea

The effects of different drying methods on volatile components of Chongqing local green tea were studied in this research.Gas Chromatography-mass Spectrometry(GC-MS)was used to analyze the components collected by Headspace Solid-phase Micro Extraction(HS-SPME),and the method of odor activity value(OAV)was employed to investigate the aroma-active compounds in different ways of drying process.The results were as follows:A total of 120 kinds of volatile components were identified in these tea samples,mainly including alcohols,esters,alkene and aliphatic hydrocarbon compounds.Compared with baking,the samples that combined baking with sun-drying showed an increase in the variety of alcohols,among which the contents of linalool,trans oxidized linalool,4-terpenol,2-decene-1-ol,Neroli tertiary alcohol and other terpenols increased significantly,while no obvious change had been observed in aldehydes and ketones.In the meantime,there were distinct differences in ester types and others presented inconsistent changes.On the whole,more volatile components could be retained by drying at 60℃,while the total content of volatile components showed a rise at first and then falling with the increase of sun-drying time under the same baking temperature.β-ionone and myrcene were the common aromatic substances among these treatments.The OAV ofβ-ionone in tea samples ranged from 351.4 to 595.7,which indicated that it had the most contribution to aroma.Moreover,the myrcene also had a significant influence on the aroma of these tea samples due to the OAVs were>1.Therefore,all tea samples showed a fragrance of(slight)sweetness,which is consistent with the sensory evaluation results.However,some special flower and fruit aroma or nut fragrance had not been identified in sensory evaluation owing to the smell that produced by sunlight.