Fabrication of zein/Persian gum particles under the effect of pH and mixing ratio and investigating their physico-chemical properties

Abstract

Abstract Zein is the main protein of corn with interesting properties such as having FDA approval for human oral consumption, biocompatibility, resistance to digestive enzymes, and easily forming nanoparticles that make it a good candidate to be used in food and pharmaceutical industries for encapsulation and stabilizing Pickering emulsions. However, hydrophobic interactions between zein nanoparticles leads them to large coagulation. Coating nanoparticles with a charged biopolymer is an efficient way to prevent aggregation behavior due to the repulsive forces in the presence of coating layer (shell). In this research, water-soluble portion of Persian gum (WPG), as an emerging polysaccharide with appropriate properties and high availability, was used to increase the zein particles’ stability. Zein/WPG composite particles were fabricated by anti-solvent method under the effect of pH (3-7) and mixing ratio (10:1-1:2) and then their properties were investigated. FT-IR spectroscopy confirmed the interaction between two biopolymers and TEM micrographs revealed a core-shell morphology in composite particles. Incorporating WPG and pH reduction caused higher fluorescence emission at 303 nm. The presence of WPG increased the relative viscosity and the highest values were measured at pH 5 for both control zein and zein/WPG particles. The mixing ratio was more effective than pH on viscosity. The average size ranged from 218.6 nm for mixed particles at 1:1 mixing ratio and pH 3 to 7.53 μm for zein particles at pH 5. The results of this study can be used for fine-tuning of nanoparticles’ characteristics made from prolamins and anionic polysaccharides for different applications like encapsulation and interfacial stabilization.