Effect of different milling mechanical forces on the structures and properties of wheat flour.

Size reduction by milling of endosperm granules produces flour and prompts the heterogeneous distribution of nutrients, changing its properties. The effects of impact milling and frictional milling on the breakage of endosperm granules were evaluated. Comparison of both methods showed that frictional milling initially squeezed larger starch granules out of the endosperm granules, and the flour particles were smaller and exhibited decreased relative crystallinity. Meanwhile, impact milling peeled the protein off the surface of endosperm granules, and the surface of the flour particles had higher S and N contents. Moreover, the content of random coils decreased, and the V-shaped peak disappeared. The weight loss rate of the ground samples and the maximum thermal cracking temperature of the impact-milled samples increased significantly as processing progressed. Different milling mechanical forces can be used in combination to obtain the desired flour. © 2021 Institute of Food Science and Technology.