Effect of moderate electric field on structural and thermo-physical properties of sunflower protein and sodium caseinate

Moderate electric field (MEF) was employed to sunflower protein isolate (SPI) and sodium caseinate (CAS) to change their structural and thermo-physical properties with a non-thermal approach. MEF treatment significantly reduced the average particle size with noticeable changes in the uniformity of SPI and CAS solutions. A maximum of 10% reduction in the surface tension was observed for 0.2% w/w SPI sample by applying 150 V for 20 s. This effect was less pronounced for CAS samples and for the protein concentration of 2% w/w. FTIR spectra provided an increased ?-helix content for SPI inducing a bulkier, loosened and more hydrophilic structure which is unlikely for CAS. Intrinsic Fluorescence Spectroscopy revealed that MEF treatments changed the tertiary structures of SPI and CAS. Denaturation temperatures and enthalpies of the SPI and CAS samples were decreased by MEF treatments.