Rice, wheat gluten and soy grits
formulations, predetermined using linear programming were
mixed, packed into polyethylene bags (thickness of 195 mm) and
allowed to equilibrate overnight at 5 C. Prior to extrusion, the
moisture content of each mixture was determined using a hot-air
oven (AOAC, 1990) and these data were used to calculate the rate of
added feed moisture during extrusion.