Abstract: To study the effect ofdifferent extrusion temperatures on extrusion puffing rice protein and starch physicochemical properties.With the increase of extrusion temperature,the amount of water loss increased,and the rate of rice powderdissolutionand the rate of water absorption increased,and the repose angle and sliding angle of puffed powder samples was big trend.The scanning electron microscope analysis results showed that starch grains became larger and the surface became smoother,internal cavity increased significantly,but the Xray diffraction curve was not obvious with the increasing of extrusion temperature.The different extrusion temperature did not change protein composition significantly among expanded rice powder,but resulting in a protein subunit polymerization,it appeared in the high molecular weight subunits.Compared to the original rice,the content of amino acid changed,and some amino acid changed more obviously (such as cysteine,methionine and lysine).This study revealed the reasons of the effects of different extrusion conditions on the product characteristics,at the same time,provided the theoretical basis for the rational use of selenium rich rice food.〖

Key words: extrusion, natural selenium enriched rice, physicochemical properties