Effect of twin-screw extrusion on the functional properties of soya fibre

Dietary fibre from soya residues (by-products of soya bean curd production) before and after twin-screw extrusion were fractionated into water insoluble, 5 g kg(-1) ammonium oxalate insoluble, 40 g kg(-1) KOH insoluble and 240 g kg(-1) KOH insoluble fractions. The porous property, swelling ability in water, water holding capacity and glucose retardation capacity of each fraction were evaluated. Results showed that extrusion decreased the pore sizes and there were no significant differences between glucose retardation capacity of non-extruded and extruded fibres. The 240 g kg(-1) KOH extract of fibre might play a unique role in the functional properties of fibre.