Effects of temperature, moisture and residence time in the properties of full fat soybean flour produced in a twin extruder / Efectos de temperatura, humedad, y tiempos de residencia en las propiedades de harinas de soya integral producidas en un extrusor gemelo

RESUMO

soybeans were dehulled, roll-milled into grits, conditioned to 18 or 21 per cent moisture and continuously cooked in a twin extruder at three temperature programs and two residence times. The resulting extrudates were further dired and rool-milled into flour and characterized for their physical, chemical and funtional properties. The urease activity and nitrogen solubility index (NSI) decreased with increased extrusion temperature, residence time and soybean grits moisture content. The best pre-cooked full fat flours had a urease activity lower than 0.2 and a NSI higher than 15 per cent