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 DFUpretreatment
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.