Study On Volatile Components Of Shaanxi Fuzhuan Tea

Tea is one of the most widely consumed beverages in the world, it can be classified into six different types based on different processing methods employed, including Green tea,White tea, Yellow tea, Oolong tea, Black tea, and Dark tea. Aroma is one of the key sensory factors for quality evaluation of tea. Fuzhuan tea is one of the representative dark tea in china.In recent years more and more consumers at home and abroad like drinking it for its unique flavor and health care functions. In this work, comprehensive volatile compounds of Green tea, Black tea and Fuzhuan tea which were collected from Shaanxi Province were identified by HS-SPME combined with GC-MS analysis and multivariate statistical analysis such as PCA and CA were also employed. The main conclusions were listed as follows:1. Five kinds of different raw materials(WRM/DRM/JRM/SRM/BRM) were processed into Fuzhuan tea, all samples were profiled using headspace solid-phase microextraction(HS-SPME)/gas chromatography-mass spectrometry(GC-MS) in order to identified their volatile components. The aroma compounds identified in all raw materials were Phytol,Phenylethyl alcohol, Geraniol, Dihydroactinidiolide, Benzylalcohol, trans-á-Ionone,(E)-6,10-dimethyl-5,9-Undecadien-2-one and Linalool. The principal volatile components from PCA detected in products were Caffeine, Phytol, n-Hexadecanoic acid,6,10,14-trimethyl-2-Pentadecanone,cis-hexahydro-8a-methyl-1,8(2H,5H)-Naphthalenedione,Dihydroactinidiolide, Methyl salicylate, Hexadecanoic acid, ethyl ester, Phenylethyl alcohol and Benzyl alcohol et al. Methyl salicylate, n-Hexadecanoic acid, Hexadecanoic acid,ethyl ester, Phenylethyl Alcohol, 3-Hexen-1-ol, Linalool oxideI, à-Ionone, trans-á-Ionone had a higher content in WP and DP than raw materials. These components mostly had woody, stale,flower odour indicated that Fuzhuan tea through the micro biological metabolism emerged some vital compounds advanced fungal aroma. In addition, this paper studied the influence of different pile fermentation time on Fuzhuan tea volatile composition. The study found that Fuzhuan tea for a long pile fermentation time(3 days)had a higher content of Methyl salicylate,Phenylethyl alcohol, Geraniol, Benzyl alcohol that made the products had a higher fungal aroma.2. HS-SPME/GC-MS were applied to extract and identify the volatile components ofFuzhuan tea samples from Hunan and Shaani produced in 2014. Total of 102 volatile components were identified in all samples, the key compounds contributed to the characteristic“fungal aroma”of Fuzhuan tea including Methyls alicylate(herbal), Linalool and Linalool oxide(woody/floral/fruity), α-Ionone(violet/woody) and β-Ionone(violet/woody),(E)-6,10-dimethyl-5,9-Undecadien-2-one(rose/fruity) and Geraniol(rose/fruity), β-ionon-5,6-epoxide(stale), Dehydro-β-ionone(woody). The volatile composition in most Shaani Fuzhuan tea were similiar to numerous Hunan Fuzhuan tea, while the mainly volatile composition of Fuzhuan tea were ketones, aldehydes and alcohols.3. In order to explore the difference of volatile components in Shaanxi Fuzhuan tea with other tea, Black tea and Green tea which were produced in Shaanxi were analyzed using HS-SPME/GC-MS. Geraniol, Methyl salicylate, Linalool, Linalool oxide and Phenylethyl alcohol were the mainly components that made Shaanxi Black tea has unique floral and sweet fragrance. Xixiang green tea is mainly including Geraniol, Linalool oxide, Linalool,2,4-dimethyl-Benzaldehyde, Pentanol, Hexanal and 3-Hexen-1-ol that made Shaanxi Green has refreshing and floral fragrance. Besides, Dehydro-β-ionone(woody), 1,2,3-Trimethoxybenzene, 1,2-dimethoxybenzene, β-Ionon-5,6-epoxide and Dihydroactinidiolide can make a distinction between Fuzhuan tea and other tea.