Duckweed as a Sustainable Source: Extraction and Applications of Bioactive Nutrients for Industrial Applications

Abstract

Duckweed, a fast-growing aquatic plant belonging to the Lemnaceae family, has been most commonly studied and utilised as a food source due to its excellent palatability and nutrient profile. Other genera, such as Lemna, Spirodela, and Landoltia, are less commonly consumed by humans due to factors such as poor palatability. However, they remain of interest for animal feed and bioresource applications. Therefore, duckweed is recognised as a sustainable, nutrient-rich food source, offering a viable solution to global challenges in food security, environmental sustainability, and nutrition. Across its diverse species, duckweed exhibits considerable variation in macro-and micronutrient composition, including 25-40% protein by dry weight, significant amounts of starch, polyunsaturated fatty acids (PUFAs), essential amino acids, vitamins, and minerals, contributing to its balanced and functional profile as an ingredient for food formulations. Various extraction methods have been employed to isolate bioactive compounds from the duckweed matrix. Advanced techniques, such as enzymatic hydrolysis, microwave-assisted extraction, and ultrasonication, have been applied explicitly to duckweed to facilitate the efficient recovery of high-quality starch, fats, proteins, and bioactive compounds while preserving their functional properties and nutritional value. Additionally, novel analytical methods, including chromatography, mass spectrometry, and proteomic profiling, enhance the understanding of duckweed's species-specific nutrient composition. This review emphasises the nutritional diversity of duckweed and explores innovative technologies for extracting and purifying its active ingredients. Furthermore, it discusses the various industrial applications of duckweed, including functional foods and nutraceutical preparations, and addresses safety and public acceptance challenges. By highlighting the potential of duckweed for developing new food products, this review underscores its role in promoting global food security, alleviating nutrient malnutrition, and contributing to sustainable food systems. This area remains a research gap. Given its rapid growth, high nutrient content, and positive ecological impact, duckweed emerges as a critical resource capable of meeting the needs of a growing population.