Enzyme-Assisted Extraction of Plant Proteins

Enzyme-assisted extraction (EAE) is an environmentally friendly green processing technique used to aid protein extraction from different plant sources. This is due to its mild operating conditions, reduced waste generation and low energy consumption compared to chemical and physical extraction approaches. A range of food grade carbohydrase and protease preparations have been employed to aid protein extraction/solubilisation from different plant sources by hydrolysis of the plant cell wall and the proteins therein. Different statistical tools can be employed to optimise enzyme treatment parameters including enzyme:substrate, pH, incubation temperature and hydrolysis duration to yield maximal protein recovery. While EAE facilitates protein recovery, it may also enhance the nutritional (digestibility) and techno- and bio-functional properties of the extracted proteins, particularly when using protease-assisted extraction. Combining EAE with physical techniques, e.g., ultrasonic processing, for biomass pre-treatment can enhance plant cell wall disruption with a view to enhancing protein extraction efficiency. This approach can facilitate economic feasibility by reducing the energy required and the quantity of enzyme used and, therefore, the overall cost of the extraction process. An overview of the application of EAE in protein/peptide recovery from different plant sources including oilseeds, nuts, cereals, pulses and algae is provided herein.