Construction And Application Of Fujian Tieguanyin Fingerprint

HS-SPME-GCMS was used to anlyze the volatile components in the lingering charm type Tieguanyin tea from different producing areas and different seasons.The similarity calculation,peak overlap caculation,cluster analysis and principal component analysis were used to visualize the fingerprint of Tieguayin.Then using HPLC as the detection method,the external standard method was used to quantitatively analyze 8 catechin compounds and caffeine in 15 Tieguanyin tea belong to different lingering charm type,and the principal component analysis was used to construct the quality fingerprint of Tieguanyin,the results were as follows:(1)The number,sensitivity and repeatability of the volatile components of the extraction of Tieguanyin from three kinds of extraction fiber of PDMS,PDMS/DVB and PDMS/CAR/DVB were compared.The 50/30 ?m DVB/CAR/PDMS SPME fiber is the optimum SPME for extracting the volatile components in the Tieguanyin tea.The best extraction time is 60 min and the optimal extraction temperature is 70°C.(2)Analyzing the volatile components of Tieguanyin tea in different seasons,the number of volatile components in spring tea is less than the number of volatile components in autumn tea.The content of ?-farnesene,nerolidol and indole,which are the highest in Tieguanyin,are diverse in different seasons.Cluster analysis and principal component analysis were used for the seasonal identification of Tieguanyin in 6 different habitats.Both of them show a good discrimination effect for the different Tieguanyin picking seasons in other five producing areas except of a few samples from Xiandu.The combination of principal component analysis and cluster analysis can effectively improve the accuracy of identification of all samples.(3)Choosing the cosine value similarity,peak overlap ratio,cluster analysis and principal component analysis methods,analysis of the volatile components of Tieguanyin from six different production areas,and build the fingerprint of Tieguanyin from different producing areas.The cosine similarity and the peak overlap ratio can reflect the discrepancy in different producing areas to a certain extent.Cluster analysis shows good discrimination effect on Anxi producing areas;Principal component analysis method has better discrimination effect on some producing areas of Anxi,Datian and Hua'an.(4)Quantitative analysis of eight catechins and caffeine in the chemical composition of Tieguanyin methanol elution by HPLC.Analysis of catechin compounds in two level Tieguanyin species found that there was a significant difference in the content of EGCG between superior Tieguanyin and good-grade Tieguanyin,the content of EGCG in superior Tieguanyin is about twice as that of the good-grade Tieguanyin.Different quality Tieguanyin HPLC fingerprints constructed using principal component analysis can distinguish Tieguanyin of different qualities.