Duckweed as a sustainable protein source: extraction methods, functional properties, and applications in food systems

Duckweed has gained significant attention as a sustainable protein source due to its rapid growth, high protein content (up to 45 % dw), and well-balanced amino acid profile. Its potential as alternative to traditional plant-based proteins is explored, focusing on the extraction and purification methods that enhance protein yield and bioactivity. Techniques, including ultrasound-assisted extraction, high-pressure processing, and pulsed electric field, are highlighted for their ability to improve protein efficiency and functionality. Duckweed proteins exhibit valuable properties such as emulsification, foaming, and gelling, along with potential to produce bioactive peptides with health-promoting benefits. However, challenges such as heavy metal contamination, allergenicity, and the need for pure production remain barriers to large-scale commercialisation. A systematic search was carried to write this review article using PRISMA. Future research is essential to develop bioengineering solutions and optimise cultivation methods to fully explore duckweed's potential in contributing to sustainable food systems and the circular economy.