Degradation of Wheat Starch in a Single Screw Extruder: Characteristics of Extruded Starch Polymers

✍ Scribed by V. J. DAVIDSON; D. PATON; L. L. DIOSADY; G. LAROCQUE

• Book ID: 108810399
• Publisher: Institute of Food Technologists
• Year: 1984
• Tongue: English
• Weight: 812 KB
• Volume: 49
• Category: Article
• ISSN: 0022-1147
• DOI: 10.1111/j.1365-2621.1984.tb12441.x

✦ Synopsis

Wheat starch was processed in a 19 mm diameter, single screw extruder to study the physical and structural modifications that occur during extrusion cooking. Structural modification of the starch polymers was investigated using gel permeation chromatography (GPC), enzymatic digestions and dilute solution viscometry. Both the GPC and intrinsic viscosity results showed that the average molecular size significantly decreased as a result of extrusion processing. The relative amount of material excluded by Bio-Gel A150m was considerably lower for extruded samples than for unprocessed wheat starch and this size reduction of the amylopectin fraction was attributed to mechanical rupture of covalent bonds. The characterization of the structural modifications of the starch polymers is reported.