ABSTRACT
Good bread-quality wheat flour is an optimum blend of starch, proteins, lipids, pentosans, enzymes and enzyme inhibitors, and other minor components. Proteins constitute about 8 to 18% of wheat flour, yet despite a relatively minor presence, compared to starch, this component is technologically the most important. The importance of wheat flour is attributed mainly to the unique viscoelestic properties of the gluten proteins, a water insoluble complex. The high molecular-weight glutenin polymers exhibit a strong tendency to aggregate, reflecting polypeptide chain composition. The main attributes for this structure-forming behavior are a large potential for interpolypeptide chain disulphide bonds, considerable hydrogen bonding, and potential for polar bonding of the many polar side chains and low ionic character of the gluten proteins. Native wheat starch granules contain about 30% crystallite material and yield X-ray diffraction patterns corresponding to A polymorphs.
