THE EFFECTS OF EXTRUSION CONDITIONS ON THE PHYSICAL-PROPERTIES OF WHEAT-FLOUR EXTRUDATES

The effects of extrusion conditions (feed moisture content and rate, p rocess temperature, screw speed and geometry, and die diameter) on exp ansion ratio, bulk density, and breaking strength of wheat flour extru dates were investigated. Extrudate samples were prepared by using a Br abender single-screw extruder. Higher feed moisture content and proces s temperature were required for proper expansion. At 3.18mm die openin g, the relationship between expansion and bulk density was positive. F eed rate was the most effective factor for increasing bull: density. B reaking strength was significantly decreased with increasing process t emperature. Under extrusion conditions of 22% feed moisture, 110g/min feed rate, 160 degrees C process temperature, and 130rpm screw speed w ith 5:1 CR, wheat flour was puffed with low bulk density and breaking strength.