Watermeal (Wolffia globosa) has emerged as a promising candidate as an alternative protein source due to its outstanding nutritional profile. This study evaluated the nutritional quality, functional properties, and biological characteristics of W. globosa. The protein content was found to be high at 26.76 g/100 g of dry weight (DW). Functional properties, including water and oil holding capacities, protein solubility, foaming, and emulsifying abilities across different pH levels, were assessed to determine optimal conditions. Amino acid profiling revealed that essential amino acids constitute 67% of the total amino acids. Polyunsaturated fatty acids (PUFAs), particularly α-linolenic (18:3 n-3) and linoleic acids (18:2 n-6), were identified as the predominant fatty acids. Additionally, watermeal was found to contain significant amounts of α-tocopherol (699 µg/g) and γ-oryzanol (100 µg/g), which contribute to its antioxidant capacity, as confirmed by DPPH and FRAP assays. The prominent protein bands were observed at around 62–67 kDa, likely representing a structural, metabolic protein (vicilin-like protein) of 38% of the total protein content. Overall, W. globosa demonstrates significant potential as a functional food ingredient, offering a rich nutrient profile and health-promoting properties, making it a promising choice for future diets.

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.

Rice husk (RH), an underutilized by-product of rice milling, represents a promising source of dietary fiber with health-promoting potential. This study investigated the effects of growth stage and particle size on the chemical composition and functional properties of dietary fiber isolated from green rice husk (G-RH) and ripe rice husk (R-RH). Cellulose contents ranged from 62 to 85 g/100 g DW in G-RH and from 38 to 73 g/100 g DW in R-RH, while β-glucan levels were 66–85 mg/g DW and 67–92 mg/g DW, respectively. FTIR and XRD analyses confirmed the presence of cellulose and its crystalline structure. Particle size reduction enhanced water- and oil-holding capacities (up to five-fold and two-fold, respectively) and increased phenolic, flavonoid, and phytosterol contents. G-RH exhibited higher levels of bioactive compounds and a more diverse phytosterol profile compared to R-RH, as verified by GC-MS analysis. In contrast, R-RH showed greater water-holding capacity, whereas G-RH displayed superior oil-holding capacity, underscoring the influence of growth stage on dietary fiber functionality. Overall, these findings highlight rice husk, particularly G-RH, as a promising functional ingredient for food applications.