Protein gel shrinkage during solvent exchange: Quantification of gel compaction, mass transfer and compressive strength

In this work, we experimentally investigate into one step solvent exchange of cylindrical shaped whey protein isolate (WPI) gels, where the pore fluid water inside pores is replaced by ethanol. Solvent has three major impacts on macroscopic gel properties, leading to an increase in compressive strength, shrinkage cylinders diameter and consequently a change spatial distribution. 1D-Raman spectroscopy was employed for in-situ investigation composition density distribution, together with conventional camera track during exchange. Compressive strength measured ex-situ using universal testing machine. For gels different concentrations, report comparable about 85% initial size, most taking place first stages exchange, when ethanol detected outermost layers only. Further prevented sharp mechanical stiffness gels. leads inhomogeneous distribution compaction towards radial center. We showed complex interaction kinetics dependent matrix controls final size gel.