Analysis of Quality Features and Aroma Components in Guizhou Representative Green Tea

In order to identify the aroma characteristics and quality of Guizhou green tea,12 samples of Guizhou green tea were analyzed using headspace solid phase micro-extraction coupled to gas chromatography-mass spectrometry(HS-SPME-GC-MS)in this study. Then the main aroma components of Guizhou green tea were identified based on odor activity value(OAV)and a comparative quantitative analysis of the aroma components identified. For this purpose,principal component analysis(PCA)was also carried out. The results showed that,firstly,50/30 μm DVB/CAR/PDMS fiber and DB-17MS were the most suitable for the extraction of volatile flavor components from Guizhou green tea. Secondly,the main chemical components of Guizhou green tea included amino acids(4.37%),polyphenols(averagely 16.81%),polyphenols to amino acids ratio(averagely 3.88),water extract(47.77%),soluble sugar(3.19%),caffeine(3.52%)and flavone(averagely 1.74%). It reflects the "tender,fresh,strong and mellow" characteristics of Guizhou green tea. Thirdly,75 components were identified in 12 Guizhou green tea samples,among which the hydrocarbons and alcohols were the majority. 31 compounds with PCA,OAV and content comparison were identified as the key odorants responsible. It was the main cause of the floral,fruity,clear and chestnut aroma of Guizhou green tea. Fourthly,Central and southern tea areas had a strong floral and fruity aroma. The main contributors were benzyl alcohol,jasmonone,and phenethyl alcohol. Acacianes add sweet aroma characteristics to the northern tea area. 3-pinene was a characteristic of pinewood in the southeast tea area. The characteristics of camphor and wintergreen oil in the tea areas of southwestern and western were due to the 2-piperidone,D-bisynthene,methyl salicylate.