Research On Extrusion Of Unpolished Rice

Technics flow of brown rice extrution cooking has been established,and extrution parameters were optimized by respond surface method.The effects of extrution cooking on starch protein,lipid,phytic acid and fiber were also analyzed.The thermal analytical characteristics of brown rice and extrudates were compared.The raw material recipe was achieved through organ analysis experiments.The results indicated that during the extrusion,the gelatinization and expansion coefficient of brown rice have something to do with the rolling speed,feeding speed and temperature.In the condition that all the other factors maintain,increase the rolling speed or feeding speed would decrease the gelatinization and expansion coefficient,on the other hand heighten the temperature may better the gelatinization of brown rice.After extrusion,the expansion coefficient of brown rice increases,it indicated that after extrusion,the solidity has been enlarged,so it strengthen the drink ability,it also indicated that,there is something changed in the micro structure of brown rice.Also the results indicated that the content of free lipid and phytic acid decreased,the content of food fiber increased,starch gelatinized,and protein intented to accumulate.The difference of brown rice and its extrudates in thermal characteristics evinced that the gelatinization of brown rice was mainly attained through melting action.The optimal conditions were:moosture 15%,screw speed 350rpm,feed speed 364rpm.