Cereal Chem 67:350-355 | VIEW
Chemical Changes During Sponge-Dough Fermentation.
K. Shiiba, Y. Negishi, K. Okada, and S. Nagao. Copyright 1990 by the American Association of Cereal Chemists, Inc.
It was demonstrated that differences in mixing tolerance between unfermented and fermented dough were not caused by organic acids produced during fermentation. Foaming activity of doughs significantly increased during fermentation. As fermentation time was increased, the amounts of acetic-acid-soluble proteins (soluble glutenin) decreased remarkably, whereas proteins soluble in 70% ethanol increased. Two hydrophilic polypeptides of the soluble glutenin increased (detected by reversed-phase high-performance liquid chromatography), and these polypeptides were characterized by their high contents of glycine. Surface hydrophobicity of acetic-acid-soluble proteins in doughs increased gradually with fermentation time when hydrophobicity was determined by hydrophobic fluorescence probe cis-parinaric acid. Molecular weight profiles by gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of all proteins from the doughs at various fermentation times showed no change. Specific lipoxygenase activity (units per milligram of protein) increased constantly during fermentation, whereas proteinase activity decreased. Those results suggested that rheological changes during fermentation were due to a decrease in surface hydrophobicity of soluble glutenin induced by binding of oxidation products of lipoxygenase.