Modeling For Quality Evaluation And UV Fingerprint Spectra Of Biluochun Tea

Biluochun is China's famous roasted Green Tea,and gets its unique quality taking advantage of local specific climate,regional condition and intercropping system.Many problems including uneven quality,fake product and poor processing techniques affect the sustainable development of Biluochun tea industry at present.In this study,Biluochun teas from East and West mountains of Dongting was chosen as raw material.The quality evaluation model for Biluochun tea was established through principal component analysis and overall evaluation.Finally,a rapid and accurate method used the qualitative of UV fingerprint technology was established.The main results are as follows:1.The important indexes of 30 Biluochun teas from 6 plants in the East mountain with 5 grades,such as water content,dry matter content,tea polyphenol,catechin,caffeine,soluble protein and free amino acids was analyzed.The quality evaluation model for Biluochun tea based on principal component analysis was established,and sorted teas according to their score.At the same time,the cluster analysis method was adopted.The results showed that there were significant differences between the Biluochun premium tea and non premium tea based the indexes which were water content,dry matter content,tea polyphenol and caffeine.And quality evaluation model is:F?0.36581 F1+0.21503F2+0.16279F3+0.11616F4.It then could be used to identify premium Biluochun from non premium ones.The cluster analysis of Biluochun tea has similar result with the principal component analysis.2.The UV spectra of 5 grades Biluochun tea from 10 different manufacturers of the East and West mountains was scanned,and the 50 samples was analyzed by the methods of principal component analysis and partial least squares discriminant analysis.The results showed that the ultraviolet spectral fingerprint can be reflected the basic information of Biluochun tea.The methods of principal component analysis and partial least squares discriminant analysis can distinguish Biluochun tea from different areas,and Biluochun premium tea and non premium tea to some extent.