Cereal Chem 68:227- 234   |  VIEW ARTICLE

Extrusion Cooking of Corn Meal and Sugar Beet Fiber: Effects on Expansion Properties, Starch Gelatinization, and Dietary Fiber Content.

S. Lue, F. Hsieh, and H. E. Huff. Copyright 1991 by the American Association of Cereal Chemists, Inc. 

Sugar beet fiber of different particle sizes (10-200 mesh) was mixed with corn meal and extruded with a twin-screw extruder. The variables studied were fiber particle size, fiber percentage, and extruder screw speed. Expansion properties, dietary fiber contents, and total and gelatinized starch contents of the products were determined. Increasing the percentage of sugar beet fiber resulted in less radial expansion and more elongation of the products. Decreasing the particle size of sugar beet fiber improved both radial and longitudinal expansion. Increased screw speed favored elongation but decreased radial expansion. Regardless of the dietary fiber content (0-30%), the starch in raw materials was completely gelatinized after extrusion as determined by an enzymatic method. The insoluble, soluble, and total dietary fiber (IDF, SDF, and TDF) contents were not significantly different among extruded products containing 30% sugar beet fiber. However, compared with the dietary fiber contents of the raw materials, IDF decreased by 0.6-1.7 g/100 g of dry solid after extrusion cooking. SDF increased slightly and TDF decreased slightly, but the differences were not statistically significant.