Abstract:The effects of hydrodynamic cavitation and enzymatic hydrolysis on the structure and physicochemical properties of skimmed okara fibers were analyzed by Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The physicochemical properties of okara fibers were strongly affected by cavitation. After 10 min cavitation, the water- and oil-holding capacities of okara fibers reached 18.43 g/g and 7.35 g/g, respectively. After 20 min cavitation, the soluble dietary fiber (SDF) content changed from 2.87% to 6.79%. Both the apparent solution viscosity and the okara fiber crystallinity decreased, and the fibers existed in the form of honeycomb sheets. In addition, enzyme-assisted cavitation could further improve the physicochemical properties of okara fibers. The properties of the products were strongly affected by the sequence of enzymatic hydrolysis and cavitation. Up to 12.52% of SDF content was obtained in okara fibers and the apparent viscosity decreased significantly when enzymatic hydrolysis was performed before cavitation. On the contrary, when enzymatic hydrolysis was carried out after cavitation, higher water- and oil-holding capacities were noted. Enzyme-assisted cavitation of okara fibers results in increased debris and small fibers. In short, the method can be an effective means to improve structural and physicochemical properties of okara fibers.
