Characterization of Soy Protein Nanoparticles Prepared by High Shear Microfluidization

Abstract

Soy protein nanoparticles were produced with a microfluidizer and characterized in terms of particle size, size distribution, morphology, rheological properties, and aggregate structure. Three stages of structure breakdown were observed when the soy protein dispersion was passed through the microfluidizer. A sudden change in the aggregate size was observed after a certain number of passes through the microfluidizer; such change was both concentration and pH dependent. Rheological measurements of these soy protein emulsions showed that both viscosity and storage/loss modulus decreased as the aggregate size of soy protein was decreased, indicating reduced interactions between the aggregates. The fractal dimension of the soy protein aggregates was estimated from the properties of a continuous matrix embedded with the aggregates.