Abstract

To investigate the quality characteristics of different size of flour particle in Qinghai-Tibet Plateau, coarse flours from twelve spring wheat varieties were sifted with sieves of 150, 75 and 44 µm. Four subfractions and the coarse flour were evaluated for protein content, ash content, protein components, and rheological properties. Mean weight percentages of >150, 75-150, 44 to 75 and <44 µm subfractions were 43.8, 37.4, 14.4 and 4.5%, respectively. The different size of flour particle had different quality characteristics. Subfraction <44 µm had the lowest protein content. 44 to 75 µm had the highest protein content, gliadin content and globulin content. It also had relatively high glutenin content. Therefore, it had the biggest SDS sedimentation value. Although subfraction >150 µm had the highest glutenin content, its SDS sedimentation value was the lowest, and its rheological properties were worse than the coarse flour and 75 to 150 µm. This indicated that big particles were not conducive to formation of nice dough.

Key words: Wheat, granularity, subfraction, quality.