Effect of surface dielectric barrier discharge plasma on the physicochemical properties of soy protein isolate-chia...

The aim of this study was to modify the soy protein isolate-chia seed gum (SPI-CSG) complex using surface dielectric barrier discharge plasma at different exposure times (2, 4, and 6 min) to improve its techno-functional potential. The present active species in the plasma were determined using optical emission spectroscopy. The results revealed that the surface properties of the complex were altered from hydrophilic to hydrophobic at 4 min treatment and then reverted to hydrophilic at 6 min due to polar group formation. The apparent viscosity and modulus decreased with increasing plasma exposure time. FTIR analysis confirmed that plasma treatment did not alter the main structure of the complex, although the intensity of the peaks changed. The main driving forces for the SPI-CSG complex formation were hydrogen bonding, hydrophobic, and electrostatic interactions. Moreover, the plasma-treated solution exhibited a reduction in particle size and increased antioxidant activity compared to the untreated solution.