Heat Coagulation of Wheat Flour Albumins and Globulins, their Structure and Temperature Fractionation

Abstract

Abstract Albumins and globulins were fractionated by coagulation at 70, 100, and 120°C and were studied by microscopic and electrophoretic methods. The coagulated albumins of a U.S. commercial hard red winter (HRW) wheat blend sample included larger aggregates than those of an Israeli spring wheat (SW). Dialyzed globulins appeared as finger-like patterns with embedded oil droplets and heat-coagulated globulins appeared as aggregates with fibril-like patterns. An increase in size of coagulated aggregates was observed as temperatures increased (70, 100, and 120°C). Differences in capillary zone electrophoresis (CZE) and sodium dodecyl sulfate (SDS) – polyacrylamide gel electrophoresis (PAGE) patterns between coagulates from samples of an Israeli SW and a U.S. commercial HRW wheat were seen at all the coagulation temperatures. SDS-PAGE patterns of coagulates obtained at lower temperatures exhibited relatively more intense bands of higher molecular weight components, and those obtained at higher temperatures exhibited relatively more intense bands of lower molecular weights.