High-pressure treatment unlocks the emulsification potential of Desmodesmus protein extract for stable high internal...

The crude protein extract from Desmodesmus sp. QL96 (DPE), a novel microalgal strain previously isolated and characterized by our team, exhibited promising antioxidant and emulsifying properties. This study investigated its potential as a sustainable stabilizer for high internal phase emulsions (HIPEs), focusing on how high-pressure treatment at 200 MPa or 400 MPa modulated its interfacial characteristics, in comparison with whey protein (WP). Moderate treatment at 200 MPa induced controlled protein unfolding, resulting in a reduced particle size (235.2 nm), enhanced surface hydrophobicity, and improved wettability (74.9°). These structural changes promoted the formation of a more viscoelastic interfacial film with elevated β-sheet content. Compared to WP, DPE subjected to 200 MPa (DPE-200) exhibited superior interfacial adsorption kinetics and lower interfacial tension. Consequently, DPE-200-stabilized HIPEs demonstrated a higher elastic modulus and significantly improved stability against long-term storage, outperforming both DPE, DPE subjected to 400 MPa (DPE-400), and WP-stabilized counterparts.