Surface modification of plant protein based nanoparticles: a tool to improve their functional properties
Plant proteins often have inferior functionality than their animal counterparts. Nonetheless, the former represent a promising class of food ingredients as the latter are often more expensive and their production less sustainable. Plant protein functionality can be improved by various strategies, one of which is the formation of nanoparticles, via a process called antisolvent precipitation. This allows to form homogeneously distributed nano-sized protein aggregates with improved functionality, such as the ability to encapsulate bio-active molecules or to stabilize air-water or oil-water interfaces. However, as this is a relatively new field of study, much is still to be learned about the relationship between the surface (structural) properties of such particles and their functionality. In addition, such particles are often unstable in conditions often encountered in food systems. Here, several strategies (chemical, biochemical) to alter the surface of plant protein based nanoparticles will be investigated. The stability of these particles in food system relevant conditions (pH, salt, temperature, storage, …) will be tested. Furthermore, their structure (size, charge, hydrophobicity, rigidity) and functionality (ability to stabilize foams and emulsions) will be investigated thoroughly. All this will lead to (i) insights in the relationship between structure and function of plant protein based nanoparticles and (ii) potential novel applications of plant proteins in food systems.