Effects of moderate electric fields on the structural and gelling properties of soybean protein isolate gel induced by glucono-δ-lactone

To investigate the effects of moderate electric fields (MEF) treatment on the gelling properties of soybean protein isolate (SPI) gels induced by glucono-δ-lactone (GDL), SPI was treated by applying different electric field intensities (EFI) before GDL-induced gelation. The structure of SPI (4% and 6%, w/v) was characterized via particle size distribution, ζ-potential, fluorescence spectra, and total sulfhydryl content. The effects of MEF treatment on the acidification pH, rheological properties, water-holding capacity (WHC), textural properties, intermolecular forces, and microstructure of GDL-induced SPI gels were investigated. The results revealed that the SPI gels treated with EFI 4 V/cm aggregated faster during acidification, with higher storage modulus, stronger gel texture, and better deformation resistance. The WHC of the gel was enhanced, and the gel network was finer and more uniform. The results suggested that MEF treatment can improve the characteristics of vegetable protein gels.