1. Tea Research Institute of China Academy of Agricultural Sciences, Key Laboratory of Chemical Engineering, Ministry of Agriculture, Hangzhou 310008, China 2. College of Chemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou 310032, China
Abstract：Crude tea polysaccharides (CTPS) were extracted from low-grade green tea, separately named CTPS-Ⅰ by water-boiling extraction method and CTPS-Ⅱ by compound enzyme method, and CTPS-Ⅲ extracted from tea leaves by compound enzyme method. The content of saccharide and protein of them were determined. The homogeneity distribution and mass ratio of polysaccharides constituent were analyzed using HPGPC-ELSD, and there were 5, 4 and 7 kinds of homogeneous constituents accordingly in CTPS-Ⅰ, Ⅱ and Ⅲ. There were six kinds of monosaccharide residues (rhamnose, arabinose, xylose, mannose, glucose and galatose) in CTPS confirmed by means of GC-MS. UV spectra discovered that CTPS-Ⅰ had a distinctive peak absorption at 257 nm, while CTPS-Ⅱ showed a shoulder-shaped peak absorption in 240-270 nm, and CTPS-Ⅲ exhibited a weak double wave-shaped absorption in 250-360 nm. In addition, the mass ratio of free protein and nucleic acid in CTPS was determined. IR revealed the characteristics of tea polysaccharides complex including related protein and nucleic acid. CD spectra showed that their conformations in water were different.
Key words：Crude tea polysaccharides(CTPS);Extraction and preparation;Spectral analysis
