Comparative effects of high-pressure and thermal processing on the nutritional and functional properties of duckweed

This study compared the effects of thermal (boiling, steaming, tray drying) and non-thermal (high-pressure processing, HPP) treatments on the nutritional and functional properties of Wolffia globosa, a rootless aquatic plant. HPP at 300 MPa significantly improved water- and oil-holding capacities, total phenolic (14.04 mg GAE/g dry weight (DW)) and flavonoid (62.14 mg QE/g DW) contents, and antioxidant activity (ABTS: 313.09 µM TE/g DW). Scanning electron microscopy showed that HPP preserved cellular structure, while boiling and drying caused collapse. HPP also reduced phytic and oxalic acids, enhancing mineral bioavailability. Steaming effectively retained chlorophyll, and tray drying moderately preserved phytochemicals. During in vitro digestion, HPP-treated samples exhibited greater phenolic and flavonoid release, though antioxidant capacity declined due to pH and enzymatic effects. Protein digestibility was highest in samples treated at 450 MPa (83.83 %), compared with thermal methods. Overall, HPP was more effective than conventional thermal treatments in maintaining and enhancing the nutritional and functional qualities of W. globosa, underscoring its potential as a sustainable ingredient in plant-based foods.