基于GC-IMS法分析不同烘焙温度对六堡茶香气品质的影响

Effects of Different Baking Temperatures on the Aroma of Liupao Tea Based on GC-IMS

为探讨烘焙对六堡茶香气是否有改善作用,研究采用感官评价和气相色谱-离子迁移谱联用技术,对不同烘焙温度的陈香型六堡茶的香气进行定性定量分析。GC-IMS共定性42个挥发性成分,经过烘焙后,与茶叶花香、果香、清香有关的醇类、酯类物质总体含量增加,其中丙醇、桉叶油醇、丙酮、乙酸乙酯等物质相对含量变化明显。六堡茶的陈味以2,3-丁二酮、丙醇等为主,随着烘焙温度的升高而减弱。60℃、30 min烘焙茶样有松烟香,80℃、30 min烘焙茶样体现为虚香、欠纯,二者香气成分以桉叶油醇、乙酸异戊酯等为主,但后者辛酮、苯乙酮、戊醛相对含量较高。100℃、30 min烘焙茶样带有青气,120℃、30 min烘焙茶样产生烘烤香;二者香气成分以桉叶油醇、丙醇为主,但前者醇类相对总量较高。烘焙有利于陈香型六堡茶香气品质的改善,为六堡茶的增香提供了技术参考。

To investigate whether baking improves the aroma of Liupao tea,sensory evaluation and gas chromatography-ion mobility spectrometry were used to conduct qualitative and quantitative analysis on the aroma of aged Liupao tea at different roasting temperatures.42 volatile components was identified by GC-IMS.After baking,the total contents of alcohols related to tea fragrance,fruit aroma and fragrance increased,and the contents of propanol,cineole,acetone,ethyl acetate and other substances changed significantly.The aged aroma of Liupao tea was mainly 2,3-butanedione and propanol,which decreased with the increase of baking temperature.At 60℃for 30 min,the tea samples had the aroma of pine smoke,while the roasted tea samples at 80℃for 30 min,the tea samples were showed deficiency aroma and owe pure,The two samples mainly contained cineole and isoamyl acetate,but the latter had higher relative contents of octanone,acetophenone,pentanal.The tea samples roasted at 100℃for 30 min had the aroma of green,120℃,30 min baking tea sample produced roasting aroma,cineole and propanol were the main alcohols,but the former had higher relative total alcohols.Baking is beneficial to the improvement of the aged Liupao tea and provides technical reference for the flavoring of Liupao tea.