Interaction between soy hull polysaccharide and mucin with sodium-/potassium-ion treatment: interfacial property

Abstract The interaction between soy hull polysaccharide and intestinal mucus is influenced by different ions. This study investigates the effects of various concentrations of Na + /K + on the stability, interfacial activity, and viscoelasticity of the microwave-assisted ammonium oxalate extraction of soy hull polysaccharide (MASP) in simulated intestinal fluids (SIFs) in terms of particle size, zeta potential, surface hydrophobicity, Fourier-transform infrared spectroscopy, shear rheology, and microstructure. Results showed that 1.5 % Na + /K + causes MASP and mucin in SIFs to bind through physical adsorption; the average particle size of the MASP/SIF miscible system increases from 1,659 to 1,881 and 1,736 nm. When the ion strength is 0.5 %, MASP rapidly reduces the SIF interfacial tension. The addition of Na + /K + causes a slight redshift in the protein amide I band and an increase in the α-helix content with respect to the decrease in the β-turn and β-sheet corner content. Furthermore, 0.5 % content of Na + and K + causes small MASP particles to adsorb onto the surface of mucin, while 1.5 % content of Na + and K + causes MASP particles to arrange above mucin after 12 h. These findings provide reference for a deeper understanding of the selection of macroelements (sodium and potassium) in the intake of polysaccharide.