Modification of cellulosic dietary fiber and comparison of its physicochemical and functional properties

Sporisorium reilianum is an emerging fungal resource rich in dietary fiber (DF), but conventional extraction yields suboptimal functionality. Using Sporisorium reilianum as raw material, the extraction process of modified dietary fiber (DF) was optimized through response surface methodology by adjusting the compound enzyme concentration, enzymatic hydrolysis time, material-to-liquid ratio, pH, and temperature. The optimal modification conditions for xylanase were a material-to-liquid ratio of 1:14.8 (g/mL), enzymatic hydrolysis temperature of 63 ℃, and pH of 6.24, with an average yield of modified soluble DF (S-SDF) of 15.1%. The swelling power, water-holding capacity, and oil-holding capacity of S-SDF were significantly higher than those of unmodified SDF. The overall adsorption capacities for cholesterol and sodium cholate of S-SDF and modified insoluble DF (S-IDF) were higher than those of unmodified IDF and SDF. The glucose adsorption capacity followed the order: S-IDF > IDF > S-SDF > SDF, and it exhibited dose-dependence. The modified DF still retained crystallinity having the same crystalline form. The monosaccharides remained predominantly composed of glucose. The modified DF showed superior adsorption capacities, enabling applications in cholesterol-lowering foods and gut health products.