Study on optimization of extraction condition of tea polysaccharide from tea residue

The water extraction and preliminary purification technology of tea polysaccharide(TPS) was studied. Main factors of extraction technology such as material-to-liquid ratio,extraction time,extraction temperature,and number of extraction times were researched through single-factor experiments. The optimum extraction technology was confirmed through orthogonal test of L9(34). The preliminary purification technologies of alcohol precipitation and deproteintion on tea polysaccharide were investigated. The optimal conditions were as follows:the ratio of material to liquid was 1∶30,extraction temperature was 85℃,extraction time was 2h for three times,ratio of concentrated solution to 95% alcohol was 1∶5,alcohol quiescence time was 6h,and the protein was removed with Sevage method for 3 times. Under these conditions,the final polysaccharide yield was 4.10%.