Cycle-optimized high-pressure microfluidization enhances techno-functional properties of faba bean protein isolate

This work investigated the influence of high-pressure microfluidization (HPM) at a constant pressure of 207 MPa for 1-6 cycles on the structural, physicochemical, techno-functional, and gelling attributes of faba bean protein (FBP) isolates. Salt-extracted FBP was used as the native protein (control). Treatment with five HPM was the most efficient treatment in reducing particle size (250 nm), while increasing protein solubility to 102.5%, antioxidant properties (DPPH: 94.77%; ABTS: 74.03%), foaming capacity, and emulsion stability index (p < 0.05). HPM also increased the absolute values of zeta potential and brightness of FBP isolates. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) displayed higher-intensity subunits with lower molecular weights (17-25 kDa) in treated samples. Fourier transform infrared (FTIR) spectroscopy and intrinsic fluorescence analyses indicated greater flexibility and mobility in its secondary and tertiary structure of HPM-treated FBP than the control. Scanning electron microscopy (SEM) demonstrated substantial degradation of protein microstructures, peaking at the fifth cycle. However, HPM treatment impaired gel properties, reducing hardness, texture, viscosity, and viscoelastic attributes, due to the breakdown of polymeric chains and intermolecular hydrogen bonds. The present results provide a promising non-thermal approach to enhance the techno-functional properties of underutilized FBP for plan-based food formulations.