THE DEFORMATION OF THIN-FILMS MADE FROM EXTRUDED STARCH

The deformation properties of thin starch films, approximately 2 mum t hick, have been investigated. The films were made by casting from solu tions of maize grits extruded at different temperatures and the strain to form shear deformation zones was measured. It was seen that the in itial processing conditions of the starch affected the properties of t he thin films. The deformation zones were initiated at granule remnant s in films made from both unextruded maize grits and grits extruded at low temperatures. More homogeneous films were produced from maize gri ts extruded at higher temperatures and these films exhibited a higher strain for deformation zone formation. However, degradation was believ ed to be responsible for lowering this strain for films made from