Abstract:
In this study, 'Zheng 103' (hard wheat) and 'Yang 15' (soft wheat) were used as raw materials, and the moisture content was adjusted to 6%, 8%, 10%, 12%, 14% and 16% by conditioning and drying the wheat to investigate the effects of moisture content on the physical properties, mechanical properties, milling performance of wheat, and the quality of wheat flour after milling, so as to provide theoretical support for the application of low-moisture milling. The results showed that: With the decrease of moisture content, the wheat appeared to be wrinkled and the geometrical size decreased; the bulk density and hardness appeared to be significantly increased (
P<0.05), and the thousand kernel weight was significantly decreased (
P<0.05). When moisture was reduced from 16% to 6%, the rupture force of wheat kernels was elevated, but the energy consumed to undergo 50% deformation was reduced by 61% and 73% for 'Zheng 103' and 'Yang 15', respectively. The milling energy constants were reduced by 46.7% and 47.5% (corrected on a 14% wet basis), the milling rate was increased by 16.4% and 20.6%, and the energy consumption for milling was reduced by 48.0% and 45.2% (corrected on a 14% wet basis). The wheat flour protein, lipids, dietary fiber and other nutrients increased significantly (
P<0.05). Ash content increased by 144.6%, 135.0% (corrected on a dry basis), and the
L* value of wheat flour decreased significantly (
P<0.05), indicating that the processing precision of wheat flour declined; the content of broken starch declined from 16.7, 20.1 UCD to 10.1, 12.7 UCD. However, the grain size of wheat flour distribution increased, gluten quality deteriorated, pasting characteristics changed, and flour paste viscosity decreased. Low-moisture wheat seed milling can reduce the energy consumption of milling while lowering the processing precision and retaining the nutrients of wheat, and this study provides a new milling method for the processing of highly nutritious whole-wheat flour.