Nutritional Composition and Bioactive Profiles of Farmed and Wild Watermeal (Wolffia globosa)

Abstract

This study assessed the nutritional composition, bioactive compounds, phytosterol content, amino acids, and fatty acid profiles of watermeal cultivated under farm conditions (WF1) and harvested from natural environments (WF2 and WF3). WF1 exhibited the highest levels of protein (22.7%), dietary fiber (16.5%), total phenolic content (3.9 mg GAE/g DW), and total flavonoid content (5.0 mg QE/g DW). Chlorophyll and β-glucan contents were comparable across all samples. WF1 also showed the highest total amino acid content, while WF2 had the highest lysine and tryptophan levels. Although essential amino acid profiles were slightly below WHO/FAO/UNU reference values, watermeal remains a promising complementary plant protein source. Fatty acid analysis revealed a consistently high α-linolenic acid content (30%) across all samples, highlighting its value as a natural source of omega-3 fatty acids. Minor differences in amino acid and fatty acid profiles suggest an influence of environmental conditions. The most pronounced difference between the farmed and naturally sourced samples was observed in phytosterol content, which was highest in the farmed sample. Overall, despite variations in cultivation sources, watermeal consistently exhibits a rich nutritional profile, reinforcing its potential as a sustainable, nutrient-rich biomaterial for functional food applications.