Abstract: Rice protein was grafted with dextran of 20 kD in solution by using microwave radiation. Based on the degree of graft(DG) ,the single factors affecting the graft reaction were tested firstly. Then by means of orthogonal design,the optimal reaction conditions are determined as follows:concentration of rice protein 3 mg/ml,weight ratio of rice protein to dextran 1:6,power of microwave radiation 500 W,and reaction time 20 min. The results of amino acids analysis and HPLC showed that the contents of Arg and Lys decrease and the area of macromolecular increases. With the increase of DG,the solution and emusifying propertise improve greatly.

Key words: rice protein, dextran, graft reaction, microwave radiation, functional property