Microstructure of Mixed Gelatin‐Egg White Gels: Impact on Rheology and Application to Microparticulation

Abstract

The microstructure of mixed gelatin‐egg white gels was examined by using both light and electron microscopy. Interpenetrating polymer network morphology was observed in mixed gels that were macroscopically single‐phase systems. For two‐phase gels, phase volumes were determined by optical image analysis and used to predict the composite shear modulus. Rheological properties were related to observable changes in the gel microstructure. For systems containing 5.6% egg white protein and greater than 5% gelatin, the dispersed egg white phase formed capsules of roughly 1–2 μm in diameter, with a dense outer coat and a less dense interior containing voids. From this, a method for the microparticulation of proteins based on aqueous phase partitioning was developed.