Plant-protein stabilized emulsions as β-carotene delivery systems: colloidal stability and behaviour during in vitro digestion conditions

). In terms of colloidal stability, at both pH levels the Tween 80 nanoemulsion remained stable with a consistent size of ∼0.2 µm. At pH 3.0, wheat protein emulsions were highly stable, forming fine droplets (0.42 µm) and increased electrostatic repulsion (+15 mV). Conversely, soy and pea emulsions were unstable at pH 3.0 (droplets >6 µm) but stabilized at neutral pH, where wheat emulsions destabilized (droplets >7 µm). The small size of the Tween 80 nanoemulsion enabled the fastest (24.5%/min0.5) and most complete (79.5%) lipid digestion, while protein emulsions digested slower. Notably, wheat protein emulsions at pH 3.0 achieved a superior β-carotene bioaccessibility (14.5%), comparable to the Tween 80 nanoemulsion (12.5%). This performance was attributed to efficient proteolysis and micelle formation. Soy and pea proteins had lower bioaccessibility (8-10%). These findings show that wheat protein at acidic pH is a promising clean-label strategy for enhancing both emulsion stability and nutrient bioaccessibility.