This project aimed to investigate a novel way to process plant-based proteins into functional materials, such as microcapsules and packaging films. Plant-based proteins are natural polymers that can be obtained from renewable biomass sources, such as leguminous crop residues, making them a promising candidate for replacing petroleum-based plastics. In particular, proteins have a unique ability to form various structures at molecular level, including highly crystalline beta-sheets and amorphous random coil. This offers various physical properties that are not available in other biopolymers. However, many commercial plant-based proteins are denatured and aggregated largely during the extraction process, making them highly crystalline with high amount of beta-sheet structure. This leads to their poor solubility in water, and thus it is challenging to process them into functional materials. As a result, current approaches are often limited to a laboratory scale.
This research aimed to address this issue by investigating interaction between plant-based proteins and various solvents. Protein-solvent interaction is a core for the formation of various protein secondary structures. Controlling protein-solvent interactions and tuning protein-protein interactions opens new route for processing these proteins into materials. Such approach has a potential to enable thermoplastic processing of plant-based proteins, where polymeric materials are melted at high temperature and solidified into a shape upon cooling down. Thermoplastic processing is a particularly scalable approach and commonly used in industry to process petroleum-based polymers, thereby this will help us scale up the generation of plant-based protein materials and introduce a new sustainable plastic alternative into our society. This part was explored in WP1 and WP2 in this project.
Furthermore, this research aimed to utilize the knowledge on solubility of plant-based proteins in various solvents to encapsulate hydrophobic ingredients by a protein shell. By improving the dissolution of plant proteins in solvents, a range of phase behaviours can be explored. Having access to these phases behaviours allows us to use more efficient and benign encapsulation techniques instead of traditional spray-drying methods. With such improved functionality and performance, these microcapsules can offer alternative solutions to the petroleum-based microcapsules widely used in personal and homecare products. This part was explored in WP3 and WP4.
