Effects of Preheating Temperature,Moisture and Sodium Metabisulfite Content on Property of Maize Flour Dough

Processing temperature,maze flour particle size,and level of water and sodium metabisulfite were varied during the preparation of maize noodles.Preheated to 90-95 ℃ a mixture of maize flour or meal,water(43%-45% moisture) and salt enabled the preparation of noodles using a pasta extruder.Maize flour with smaller particle size yielded better noodles than did maize meal.The addition of sodium metabisulfite enabled the production of noodles at lower processing temperatures; however,cooking losses increased.Processing maize flour with higher water absorption yielded noodles that required longer cooking time but with decreased losses.The functionalities of starch and protein in raw ingredients and in products were determined.Starch gelatinized and retorgraded during processing maize noodles,as indicated by changes in pasting viscosity curves.Maize proteins contributed to the increased viscosity of dough above 40 ℃.The increased integrity of cooked maize noodles,however,corresponded to the increased amounts of gelatinized and retrograded starch.