Ultrasound assisted enzymolysis of sunflower meal protein: Kinetics and thermodynamics modeling

This study examined the effect of dual-frequency ultrasound (DFU) pretreatment on thermodynamics and kinetics of sunflower-meal protein (SMP) using alcalase to improve efficiency in enzymolysis process. The concentration of hydrolyzed protein and kinetic parameters after traditional pretreatment (control) were investigated and compared with DFU-assisted enzymolysis. The results indicated that DFU-pretreatment enhanced SMP-enzymolysis efficiency at different substrate and enzyme concentrations, temperature, and pH. Kinetics analysis showed DFU-pretreatment reduced the Michaelis constant by 11.29%, while the apparent breakdown rate constant increased by 1.96%, indicating DFU-pretreatment improved the affinity among substrate and enzyme. The rate constants for DFU-pretreatment were increased by 45.96, 26.92, 21.14, and 27.89% at 293, 303, 313, and 323 K, respectively (p < .05). On Arrhenius kinetics, DFU reduced the activation energy, enthalpy and entropy by 24.28, 26.13, and 9.10%, respectively (p < .05). DFU had slight influence on Gibbs-free energy when temperature increased from 293 to 323 K. The positive impact of DFU pretreatment of sunflower meal protein on enzymatic hydrolysis kinetics makes this method suitable for use in the pharmaceutical and food process industries to yield peptides from residues of oil industry.