关键词: 乌龙茶, 多糖, 分离纯化, 理化性质, 活性

Abstract: During the process of Oolong tea, the extraction rate of TPS and the contents of its neutral sugar and protein decreased, particularly notably after the third shaking, but the content change of uronic acid was less. It was also indicated that the inhibiting effects of polysaccharide on radicals increased before the third shaking, and then decreased on Zuoqing stage. According to the changes of polyphenol content, when it was retained 85%, the content of TPS was highest and the effect on scavenging •OH and was best, which was regarded the technical index to end shaking during the process of Oolong tea. Four fractions of OTPS was obtained by DEAE-52 column chromatography, and there were obvious differences not only in contents of neutral sugar, uronic acid and protein of OTPS, but also in inhibiting effects on hydroxyl radical (•OH) and superoxide anion radical ( ). OTPS 2-1, a main fraction of OTPS, was obtained by DEAE-52 and Sephadex column chromatography. It was found that OTPS2-1 was a trinal compound of polysaccharide containing rich uronic acid and less protein. The results also showed that the molecular average-weight of OTPS2-1 was 8.877?10⁴, and it was composed of Gal, Glu, Ara, Fuc and Rha with a molar ratio of 7.58:2.14:7.05:1.76:1.02.

Key words: Oolong tea, Polysaccharide, Separation, Physical-chemistry characteristics, Activity