不同树龄武夷水仙茶多糖抗氧化活性研究

为探明不同树龄武夷水仙茶叶中主要生化成分及其茶多糖的抗氧化活性的差异,以树龄为6、30、60a的武夷水仙茶叶为试材,测定了主要生化成分含量,通过水提醇沉淀法提取茶多糖,分析了茶多糖的基本组分,并研究了3种茶多糖清除DPPH自由基和超氧阴离子自由基的活性。结果表明:3种水仙茶叶中茶多酚、游离氨基酸和黄酮类含量随着树龄的增长逐渐降低,可溶性糖含量随树龄的增长而升高;3种武夷水仙茶多糖的得率及其组分中的中性糖、蛋白质、糖醛酸、茶多酚的含量存在明显差异,茶多糖的得率随树龄的增长而提高,得率较高的老丛水仙茶多糖组分中的中性糖、蛋白质的含量也较高;3种茶多糖清除DPPH自由基的能力较为接近,其IC50分别为:0.051、0.055、0.060mg·mL-1;3种茶多糖清除超氧阴离子自由基的能力存在明显差异,其IC50分别为:1.131、1.121、0.431mg·mL-1,树龄为60a的老丛水仙茶多糖清除超氧阴离子自由基活性明显高于树龄为6和30a的水仙茶多糖,具有较强的抗氧化活性。

Study on Antioxidant Activity of Tea Polysaccharides of C.sinensis cv.Fujian-shuixian with Different Ages

In order to explore the difference of chemical components and the activity of tea polysaccharides of C.sinensis cv.Fujian-shuixian with different ages,taking three kinds of C.sinensis cv.Fujian-shuixian as materials which tea plant ages were 6,30 and 60years,the contents of flavonoids,free amino acids,soluble sugar,tea polyphenols and other major biochemical components were measured,as well as tea polysaccharides（TPS）,contents of protein,neutral sugar,uronic acid and tea polyphenol.The scavenging activity of DPPH and O-2·by TPS were compared.The results showed that the contents of flavonoids,free amino acids and tea polyphenols decreased with the increasing of tea tree age,while the content of soluble sugar increased.There was a very significant difference in the contents of uronic acid,neutral sugar,protein and tea polyphenol of TPS,and the yield rate of TPS,the content of neutral sugar and protein in TPS increased with the increasing of tea tree age.The scavenging ability of DPPH of TPS with different tea tree ages were close to each other,IC50 were 0.051,0.055 and 0.060mg·mL^-1 respectively,the scavenging ability of O-2·of TPS with different tea tree ages were significantly different,IC50 were 1.131,1.12 and 0.431mg·mL^-1 respectively,it illustrated that TPS of C.sinensis cv.Fujian-shuixian for 60 years had better radical scavenger than the other two which possessed a strong antioxidant activity.