Effect of Milling Methods and Bran Particle-Size Control on the Quality and Noodle-Making Performance of Purple...

This study investigated the influence of milling method and particle size on the physicochemical, structural, and functional properties of purple whole wheat flour (WWF), as well as their impact on noodle quality. WWF samples were prepared using jet milling (JM) or ultracentrifugal milling (UM), along with five reconstituted blends, and compared with two commercial WWFs. JM produced much finer particles than UM (d₉₀: 15.9 vs. 451.4 µm), leading to higher flour brightness (L*: 87.0 vs. 76.1), water absorption (165.6% vs. 88.0%), and starch damage (18.4% vs. 5.7%). Microscopy revealed extensive particle fragmentation in JM, altering sedimentation and pasting behavior. JM also showed higher total phenolic content and antioxidant activity in both flour and noodles, indicating enhanced bioactive release. However, excessive fineness impaired dough mixing and cooked-noodle texture. Reconstituted WWF samples demonstrated that targeted bran particle-size control can balance nutritional and processing qualities. These findings highlight particle-size management as a key strategy for developing whole wheat noodles with both desirable quality and enhanced nutritional value. PRACTICAL APPLICATIONS: The selective application of superfine milling, particularly to bran and shorts, can enhance the antioxidant activity and functional potential of purple whole-wheat flour while preserving desirable dough handling and noodle quality, and supporting the development of high-value whole-grain foods.