Combined plant protein modification and complex coacervation as a sustainable strategy to produce coacervates encapsulating bioactives

Abstract Microencapsulation by complex coacervation using proteins and polysaccharides has attracted much attention due to high payload, high encapsulation efficiency, high thermal stability, and a complex structure that allows the sustained release of core materials. Animal proteins and polysaccharides are widely used to produce complex coacervates with excellent physicochemical properties. Although complex coacervates based on animal proteins offer many advantages, the production of animal proteins is linked with high cost, environmental impact, and the spread of animal diseases and drug-resistant pathogens. To mitigate these issues, plant proteins are used as an alternative to animal proteins during complex coacervation. However, plant proteins have a restricted use due to their low solubility, low flexibility and poor emulsifying properties. Although some plant proteins have low physicochemical properties, their use is regarded a sustainable solution due to their abundance in nature, low health and environmental effect. Physical, chemical and biological techniques are used to improve the properties of plant protein-polysaccharide coacervates. This review summarizes the recent advances in microencapsulation of bioactives by complex coacervation using plant protein-polysaccharide and their limitation, gaps and challenges. The design and development of complex coacervates using plant proteins and polysaccharides for bioactive encapsulation, with an emphasis on integrated plant proteins modification and complex coacervation are discussed. The potential of several modification techniques to improve functional properties of plant protein-polysaccharide coacervates and microcapsules are presented. This review delivers the key findings on the potential of integrated plant protein modification and complex coacervation for consideration in future development of encapsulation systems.