Effects of Chlorination and Heat-Treatment of Wheat Flour on Starchy Foods

Chlorination of wheat flour improved the pancake textures (higher springiness and lower gumminess) and increased the pancake volume. From results of the pancake baking tests with reconstituted wheat flours, the improvement of the pancake textures was dependent on chlorinated prime starch fraction, and the increase of pancake volume was dependent on the chlorinated gluten fraction. Microscopic observation showed that the nature of the chlorinated starch granule changed from hydrophilic to hydrophobic (lipophilic), which had relationship to the improvement of the pancake textures. Protease experiments of the chlorinated wheat starch granules and model experiments using protein-coated chlorinated glass powder that the hydrophobicity (lipophilization) was caused by the change of starch granule surface proteins. The pancake textures also showed the same improvement when wheat flour was heat-treated. Heated wheat starch granules also showed strong hydrophobicity (lipophilization), which is also caused by the change of starch granules surface proteins. These chlorinated and heated wheat starch granules have shown to bind to the tailings fraction in wheat flour and the same phenomenon was also observed in pancake crumb baked with this treated wheat flour. The binding of these fractions was caused by the hydrophobicity of the starch granules and rigid cake cell wall could be formed and showed good pancake textures (higher springiness and lower gumminess).