Modified Okara Dietary Fiber Emulsion as a Fat Replacer in Cheese Sticks

This study evaluated the effects of ultrasonication, enzymatic hydrolysis, and combined ultrasonication-assisted enzymatic treatments (cellulase and xylanase) on the physicochemical and structural properties of okara insoluble dietary fiber (OIDF). U-OIDF and UE-OIDF exhibited enhanced functional group exposure and loose, porous microstructures after modification, improving emulsifying capacity, water/oil retention, and swelling. The combination of 400 W ultrasonication and enzymatic treatment yielded maximum results, with the highest emulsifying activity index (26.74 m²/g), water-holding capacity (17.81 g/g), oil-holding capacity (7.78 g/g), and swelling capacity (15.17 mL/g). Emulsions produced under these conditions demonstrated superior modulus, viscosity, and stability across pH, temperature, and ionic variations. Substituting up to 50% of cream cheese with 400UE-OIDF in cheese sticks maintained acceptable flavor and texture. These findings indicate ultrasonication-assisted enzymatic treatments as a promising approach to enhance OIDF functionality for low-fat food applications.