Assembled protein nanoparticles in food or nutrition applications

Proteins are one of the essential components of nutritional food materials and an excellent source for food-grade nanomaterials. This review focuses on select examples of nanoparticles assembled naturally, found in food-relevant materials, major approaches in assembling nanoscale structure from proteins, and general applications of protein nanoparticles in food or nutrition. Animal-sourced casein and non-animal grain storage proteins and legume storage proteins are discussed in terms of their structural assemblies. Protein solubility is a key factor in assembling protein nanoparticles with desired functional properties. Desolvation is the most common technique to prepare protein nanoparticles for insoluble proteins. Well-hydrated protein assemblies have been extensively studied through electrostatic complexes, assembled with fatty acid and starch, reassembled protein structure, and nanogels. These protein-based nanoparticles have been utilized for filler materials of films, encapsulation of bioactive molecules, and stabilization of emulsions. Most studies exploiting protein-based nanoparticles have focused on developing technologies in extraction of proteins from sources and assembly of nanoparticles in different environmental conditions.