The physicochemical characteristics and phenolic bioaccessibility of defatted millet bran powder prepared using superfine grinding

Abstract

Since defatted millet bran (DMB) is considered unpalatable and its poor application performance means that it is only used as animal feed, this product is wasted and underutilized. This study altered the shapes of processed DMB particles using superfine grinding technology, physically overcoming the binding forces within the material. This reduced the particle sizes and surface roughness while increasing the tap density, peak temperature, and angles of repose and slide. Superfine grinding significantly disrupted the cell wall matrix, substantially increasing the total phenolic content (TPC) and antioxidant properties compared to coarse and fine powders. Additionally, the superfine powder exhibited high phenolic compound bioaccessibility (vanillic, protocatechuic, syringic, ferulic, and isoferulic acid, and 2,3-dihydroxybenzoic). These findings highlighted the potential use of superfine grinding technology to expand DMB application as a functional food.