Nanofibrillated cellulose derived from rice bran, wheat bran, okara as novel dietary fibers: Structural, physicochemical, and functional properties

The structural, physicochemical, and functional properties of nanofibrillated cellulose (NFC) derived from rice bran (RB), wheat bran (WB), and okara were investigated and explored its potential as novel dietary fibers (DF). Cellulose microfibers (CMF) with cellulose purity of 87.4 % (RB), 92.1 % (WB), and 95.1 % (okara) were prepared by alkali and bleaching treatment, respectively. Subsequently, cellulose microfibers were prepared into NFCs with nanoscale diameters by dynamic high-pressure microjet treatment. Fourier transform infrared (FTIR) spectroscopy demonstrated a significant decrease in the intensity of characteristic absorption peaks of lignin and hemicellulose after chemical treatment. X-ray diffraction results indicated the order of relative crystallinity is: NFC (56.9 %) > CMF (50.8 %) > DF (26.1 %). Moreover, NFC exhibits higher water/oil holding capacity, swelling capability, nitrite/cholesterol/sodium cholate adsorption capacity than CMF and DF. Besides, NFC exhibited superior ability to inhibit starch and lipid digestion compared to DF. Consequently, NFC holds great promise as a novel dietary additive in the food industry.