optimizing the condition for production of masa flour

corn tortiilas are flat breads made from corn dough (masa) which is prepared through the nixtamalization process (alkaline cooking). corn, in nixtamalization, is cooked in a lime solution then the boiled maize is steeped in cooked liquor , following by washing out and milling to obtain wet masa flour. drying wet masa flour in air oven produce dry masa flour. cooking temperature, cooking time , lime concentration ,and steeping time significantly affect the quality of masa flour and final product( tortilla). in this research the cross effects of these four factors , to determine the best treatment for production of masa flour, were studied. effects of cooking temperature (75,85,95°c) , cooking time ( 0,30,60 min) , lime concentration(0, 0.5 , 1%) and steeping time ( 10,14,18 hr) by measuring ph, protein content , ash content , color parameters, water absorption index (wai) and using central composite design were investigated. statistical analysis revealed the best treatment for production of masa flour as: cooking temperature 85°c, cooking time 30 min, lime concentration 0.5%, and steeping time 14 hr.