| Abstract: | Starch damage of 10.9 and 15.7%, respectively, in break and reduction flours of commercial hard wheats was increased to 16.0 and 28.6%, respectively, by pin milling. Attrition milling and cryofreezing prior to pin milling resulted in less pronounced starch damage, apparently due to reduced heat evolution and mechanical stresses as evidenced by the intensities of the X-ray diffraction patterns. Pin-milled flours exhibited chipping and splitting of starch granules as compared to surface abrasions and deep pitting on the granules from attrition-milled flours. It appeared that the latter flours would be more suitable for air classification of hard wheat flours into protein concentrates and starch fractions. |
