Cereal Chem 67:268-275   |  VIEW ARTICLE

Starch Fragmentation and Protein Insolubilization During Twin-Screw Extrusion of Corn Meal.

L.-F. Wen, P. Rodis, and B. P. Wasserman. Copyright 1990 by the American Association of Cereal Chemists, Inc. 

Degermed corn meal was extruded under 15 different extrusion conditions in a twin-screw extruder. Variables included moisture content (20, 25, and 30%), screw speed (100, 200, and 300 rpm), and temperature (100, 150, and 200 C). Extrudates were dissolved in dimethly sulfoxide (DMSO). Carbohydrate and protein were analyzed for solubility and molecular size changes. Carbohydrate solubility was not significantly affected by extrusion; however, protein solubility significantly decreased. Fragmentation patterns of the extruded starches were related to variables by response surface analysis. High molecular weight polysaccharide decreased as moisture content and temperature were decreased and as screw speed was raised. Protein became more resistant to solubilization in DMSO after extrusion. Sodim dodecyl sulfate-polyacrylamide gel electrophoresis indicated DMSO-soluble proteins did not fragment in an analogous manner as carbohydrate and also were not modified to any significant extent.