Isolation,Purification and Antioxidant Activity of Polysaccharide from Tieguanyin Tea Dust

To achieve the reuse of the waste tea resources,and to explore the antioxidant activity of Tieguanyin tea at the end of the activity of polysaccharide,the extraction of crude polysaccharide from Tieguanyin tea was optimized by water extraction and alcohol precipitation and then by DEAE cellulose and Sephadex-G100-glucan gel grade two purification,and the purity identification,infrared spectroscopy,the determination of molecular weight as well as the determination of antioxidant activity in vitro were determined. The results showed that the yield of 90% ethanol was 1.97%. TPS-1A and TPS-4C were obtained after two times of fractional purification and the purity was 96.2% and 95.1%,respectively. Infrared spectrum showed that both polysaccharides were beta glycoside bond polysaccharides. The molecular weights were 15792 and 21722 Da,respectively. The antioxidant activity of TPS-1A and TPS-4C increased gradually with the increase of component concentration. When the mass concentration was 1.2 mg/mL,the scavenging rate of DPPH radical was 95.41% and 97.71%,and the hydroxyl radical scavenging rate was 93.39% and 94.21%,respectively. The absorbance value of the total reducing force was 0.699 and 0.712.This indicated that Tieguanyin tea powder polysaccharide had strong antioxidant activity,and TPS-4C was stronger than TPS-1A.