Effect of manufacturing methods on the quality and storage stability of whole wheat meal

To investigate the effect of manufacturing methods on the quality of whole wheat meal, WWM, six types of WWM were prepared using either direct grinding or re-addition methods, with four types incorporating extrusion -puffing of bran and re-addition of germ. Quality indices of WWMs, including physicochemical properties, color parameters, particle size distribution, pasting viscosity, and storage stability, were evaluated. Additionally, the specific volume and texture of whole wheat steamed bread made from these meals were analyzed. Results indicated that WWM produced by direct grinding with a hammer mill had the largest average particle size. WWMs with germ re-addition exhibited higher crude fat and protein contents compared to those without germ, while other quality attributes showed no significant differences. WWMs containing regular wheat bran had moisture contents of 13.76% and 13.64%, significantly higher than corresponding samples. WWMs with extruded bran re-addition demonstrated significantly higher levels of soluble dietary fiber and total phenolic compounds than other groups and yielded superior-quality steamed bread. After accelerated storage for six weeks, the fatty acid values of WWF₁ (direct grinding), WWF₅（germ and extruded bran recombination）, and WWF₆ (both with extruded bran re-added) were 103.24, 92.27, and 86.99 mg/100g, respectively, while their malondialdehyde contents were 3.01, 3.06, and 3.01 mg/kg—significantly lower than those of other samples—indicating enhanced storage stability. In summary, WWF₁ (direct grinding), WWF₅, and WWF₆ (both with extruded bran re-added) exhibited greater storage stability. Moreover, WWMs with extruded bran re-addition produced higher-quality steamed bread.