Study by scanning electron microscopy of mixture of cereal proteins fractions (maize and wheat) from bread doughs prepared at high temperature in the presence of oxidants.

Protein from flour and doughs prepared at high temperature in presence and absence of oxidants (potassium bromate, potassium iodate and L-ascorbic acid) was fractionated according to solubility into water, salt, alcohol, acetic acid, soluble protein fractions and insoluble residue protein. All fractions were freeze-dried and subjected to scanning electron microscopy to observe visually the changes in protein structure. Acetic acid-soluble and insoluble residue protein are alike in structure, but the former was thermally denatured easily, while the latter was very stable to heat treatment. Salt and alcohol, soluble protein were not deformed, but the water soluble protein was deformed by heat treatment in the absence of oxidant. Oxidants generally promoted deformation of protein structure with the exception that bromate partly protected acetic acid-soluble protein from deformation.