基于HS-SPME/GC-MS/O分析滇绿茶特征香气物质OA北大核心CSTPCD

Dian green tea,a kind of green tea made from fresh leaves of large leaf tea variety in Yun-nan province,present unique aroma quality.However,its characteristic aroma compounds were un-clear.Headspace solid phase microextraction combing with gas chromatography-mass spectrometry/olfactometry(HS-SPME/GC-MS/O)was applied for the identification,quantitation,and sensory analysis of the aroma components of Dian green tea.26 samples were divided into 4 groups according to their origins.Based on the traditional green tea sensory evaluation and quantitative descriptive analysis(QDA),three Dian green tea samples with high quality were selected.The results of HS-SPME/GC-MS/O showed that a total of 83 odorants were identified in S3,S6,S15 tea infusions,and the total relative content was 10.694%.Among which,aldehydes,ketones,and aromatic com-pounds were the main constituents.Twenty-two corresponding major aroma compounds were found.Among the 43 aroma substances with higher content(＞0.05%),alcohols,aldehydes,ketones,and esters commonly present pleasure odor notes,and play a direct role in the formation of aroma quality of Dian green tea.Alcohols mainly evoked an alluring flowery and fruity aroma.Aldehydes were closely related to the formation of tea aroma and various specific aroma characteristics,and their relative contents were high in Dian green tea.Aromatic aldehydes such as benzaldehyde mainly present almond-like note,while many kinds of aliphatic aldehyde were found and they mainly showed freshy and flowery odor.Most of the esters had a strong fruity flavor.However,methyl salicylate,a common odorant in tea,had the strong freshy perception.It contributed to the aroma quality of Dian green tea significantly.Ketones were another main aroma component in Dian green tea,and their aroma characteristics were closely related to their structures.It is worth mentioning that although low contents in Dian green tea,some aroma substances such as β-damasone and(E)-4-heptenal evokes obvious aroma in low concentrations because of their low odor thresholds in water.According to the re-sults of the instrumental and sensory analysis,compounds present highest aroma intensities were 2,3-octanedione(milk-like),laurene(citrus-like/flowery),(E,E)-2,4-heptadienal(flowery),benzaldehyde(almond-like),linalool(citrus-like/flowery),hotrienol(lemon-like/sweety),geraniol(rose-like/citrus-like),limonene(citrus-like),geranylacetone(grassy),methyl sulfide(corn-like),3-methylbutanal(malty),6-methyl-5-hepten-2-one(popcorn-like/roasty),(4E,6Z)-alloocimene(basil-like),1-hexanol(grassy/almond-like),methyl salicylate(fresh,mint-like),β-damascenone(cooked apple-like),jasmonone(flowery),and β-ionone(flowery).The above mentioned com-pounds were regarded as key odorants of Dian green tea.The study characterized the key aroma com-pounds of Dian green tea,which provides the theoretical basis for aroma quality and process improve-ment of Dian green tea.