Ultrasound-assisted binary probiotic fermentation of sugarcane bagasse dietary fiber-containing synbiotics yogurt: Increased galactitol content to improve yogurt rheological properties and flavor.

The effect of ultrasound-assisted binary probiotic fermentation on the quality of sugarcane bagasse dietary fiber (SBDF)-added synbiotics yogurt were investigated. The results showed that 0.25 % (w/v) of SBDF significantly reduced yogurt syneresis. Furthermore, ultrasound-assisted fermentation with L. plantarum CGMCC 1.5953 and L. fermentum CGMCC 1.7434 improved the yogurt's texture, rheology, microstructure, and sensory scores. These improvements were supported by metabolomic analysis, which showed an 11.91-fold upregulation of galactitol and decreased concentrations of L-phenylalanine, L-glutamic acid, and L-allothreonine. Integrated sensory and molecular analyses (HS-SPME-GC-MS, UHPLC-MS) identified that enhanced texture scores were associated with SBDF-derived metabolites, including L-erythrulose, α-lactose, and erythritol. Meanwhile, the improved odor scores were associated with increased levels of ethyl acetate, hexanoic acid, and 2-nonanone. Key pathways involve galactose, tyrosine, glycine-serine-threonine metabolism, amino acid biosynthesis, and lysine degradation. This study provides valuable insights for the high-value utilization of sugarcane bagasse dietary fiber and the production of premium-quality yogurt.