Effects of ultrasound-assisted fermentation at different power levels on fermentation quality and nutritional value of a corn protein powder-wheat bran mixture

Corn gluten meal (CGM) and wheat bran are widely recognized as two major by-products generated by the food-processing industry. The corn gluten meal–wheat bran mixture (CWM) was fermented using Aspergillus niger and Lactobacillus fermentum , and the potential of ultrasound-assisted fermentation to enhance its value was evaluated. Five fermented corn gluten meal–wheat bran mixtures (FCWMs) were prepared by applying ultrasound at 0, 130, 195, 260, and 325 W for 5 min. The results indicated that ultrasound-assisted fermentation at 195 W yielded the most favorable effects. At this power level, microbial biomass was increased, while high-molecular-weight proteins were effectively degraded, resulting in substantial increases in trichloroacetic acid-soluble protein (TCA-SP) and total free amino acid (TFAA) contents. Furthermore, the levels of beneficial metabolites, including total phenolics, flavonoids, and carotenoids, were elevated. Concurrently, antinutritional factor levels were reduced, and antioxidant capacity was enhanced.