Impact of salt and homogenization on yield, aggregation, and mechanical characteristics of wheat gluten separated by batter procedure

We investigated the effects of salt addition (0%, 1%, 2%, 3%) and homogenization speed (4000, 6000, 8000, 10,000 rpm) on the yield and aggregation characteristics of gluten fractions separated through a laboratory-scale batter procedure. The gluten yield was linearly correlated with the A-starch yield and increased with salt con-centration and the homogenization rate. Adding salt and increasing the homogenization rate reduced the surface hydrophobicity and enhanced the hydration of gluten. The difference in the water-binding capacity of gluten, A -and B-starch granules is the basis for the centrifugal separation. The increase in gluten water-binding capacity promotes the separation of the three phases. Meanwhile, hydration shifted the secondary structure of gluten to beta-turn, which enhanced its tensile resistance. In the presence of salt and mechanical forces, free sulfhydryl groups undergo cross-linking reactions to generate disulfide bonds, leading to the polymerization of glutenin macro-polymer and the increase of gliadin in SDS-extractable proteins.