Extrusion conditions and zea mays endosperm hardness affecting gluten-free spaghetti quality

The effects of extrusion temperature (80, 90 and 100 degrees C) and flour moisture content (27%, 31% and 35%) on corn spaghetti quality were evaluated according to a factorial experimental design. Flours obtained from a soft and hard endosperm were processed in a Brabender single screw extruder. Corn spaghettis with good cooking characteristics and resistance to overcooking were obtained by extrusion at 27% flour moisture content for the three temperatures used. They have higher resistance to hydration, long cooking time (around 11 vs. 7 min for poor quality) and low cooking loss (lower than 9% for a 10-min overcooking). Softer endosperm allowed obtaining better spaghetti quality. Among different physicochemical properties, enzyme susceptibility could be used as an indicator of mechanical energy dissipated by friction. During extrusion cooking, the native structure is partially destroyed, and new crystalline ones, corresponding to the amylose-lipid complex, are formed.