Studies on the Gelatinization of Starch I. Competition for water by protein and cellulose derivatives

Abstract

SUMMARYSome effects of egg albumen, gelatin, methyl cellulose c(MC) and carboxymethyl cellulose (CMC) on the gelatinization of unmodified corn and waxy maize starches are reported. The effect of increasing concentrations of those four substances on gelatinization of the starch was determined at 70, 80, and 100°C, and with 40, 60, and 80% moisture. The main criterion for the amount of gelatinization was the susceptibility of the starch to beta‐amylase.Albumen, at the higher concentrations employed, inhibited gelatinization of the starches heated at 70°C with 60 and 80% moisture but did not affect degree of gelatinization at higher moisture levels or at higher temperatures. Gelatin inhibited gelatinization of the starches heated at 70°C more than did albumen, and inhibited to some degree the gelatinization of starches heated to 80°C with 60% moisture. At higher moisture levels and temperatures, gelatin had no effect on extent of starch gelatinization. Methyl cellulose significantly affected starch gelatinization at 70°C but had less and no effect at 80 and 100°C, respectively. Carboxymethyl cellulose had pronounced effect on starch gelatinization at all temperatures and moisture levels except the 80% moisture level system heated at 100°C.In bread dough containing between 36 to 38% moisture, starch gelatinization increased with temperature in the center of the loaf. The rate of increase of starch gelatinization was less than the rate of increase of temperature during baking.