Food-grade protein-based nano- and microparticles are attracting more attention given their potential application in the formulation of novel nutrient delivery systems. Gliadin is currently under-utilized in the food industry, as its application is hampered by its low solubility in water at neutral pH. Deamidation is an effective way to modify the solubility of wheat gliadin as it leads to the conversion of uncharged amide groups (glutamine residues of gliadin) to charged acidic residues (glutamate). Deamidation is, hence, a suitable technique to increase electrostatic repulsion between the protein molecules and dissociate protein-polymer clusters. In this project, only moderate levels of deamidation are focused upon as it is important that gliadin molecules will still aggregate in nano- and microparticles. As such, the effect of deamidation on particle formation kinetics will be explored. Particle formation in this project is done through liquid antisolvent precipitation. The ζ-potential of the untreated and deamidated gliadin over the pH range of 2-9 was monitored. A sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS-PAGE) test on the native and deamidated gliadin was conducted to monitor the molecular weight upon deamidation. The isoelectric point (IEP) of gliadin was shifted from pH 6.5 in native gliadin to pH 4.5 in deamidated gliadin. This IEP shift to more acidic pH conditions could improve the stability of gliadin-based nanoparticles at neutral pH conditions. The results of SDS-PAGE show an increase in molecular weight of the protein in function of deamidation degree. This can be indicative of crosslinking in deamidated gliadin and requires further study. This project will yield a better understanding of the interactions and structures underlying particle formation in function of deamidation degree. This will boost the rational development of highly customizable protein-based nano- and microparticles for nutrient-delivery and food structuring applications.

Assessing the physicochemical properties of nano- and microparticles produced with chemically modified gliadin

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.