Effects of superfine grinding on the quality characteristics of whole-wheat flour and its raw noodle product

• Superfine grinding reduced the particle size and increased starch damage of WWF.
• Superfine grinding effectively reduced the starch pasting viscosities of WWF.
• The color and cooking properties of WWN were improved by superfine grinding.
• Texture property and microstructure of WWN were enhanced as WWF at 72-μm.
• Excessive starch damage in WWF had adverse effects on the quality of WWN.

Four particle size distributions of whole-wheat flour (WWF) with mean particle sizes (MZ) of 125-μm, 96-μm, 72-μm, and 43-μm were obtained by superfine grinding. Starch damage and Farinograph water absorption were significantly affected by the reduction of particle size, while dough development time, stability, tolerance index and time to breakdown of WWF were little changed. The peak viscosity, trough, and final viscosity of WWF significantly decreased as particle size reduced. Although finer WWFs produced by superfine grinding caused more discoloration of whole-wheat noodle (WWN) after 24 h storage, they still showed brighter noodle appearance (higher L∗) than coarser WWFs. A significant increase in the cooking yield of WWN was noticed from the 125-μm WWF group to the 43-μm group, perhaps due to increasing damaged starch, while the 72-μm group exhibited the smallest cooking loss of WWN. Additionally, the hardness, cohesiveness, and resilience values of texture profile analysis (TPA) of cooked WWN significantly increased from the 125-μm group to the 72-μm group, and scanning electron microscope (SEM) analysis showed that the 72-μm group revealed the largest coverage of starch granules and degree of protein network connectivity among the WWF groups. The results demonstrated that the superfine grinding technique could improve the quality of WWN by significantly reducing the particle size of WWFs.