Plant-based oil composition modulates saltiness and bitterness in sodium-reduced double emulsions

This study investigated the effects of plant-based oil composition on the physicochemical properties, sensory perception, and digestive stability of sodium-reduced emulsions. Four edible oils (perilla, sesame, canola, and olive) were evaluated in both oil-in-water (O/W) and high internal phase double emulsion (HIPDE) systems. O/W emulsions contained either NaCl or KCl, whereas HIPDEs encapsulated KCl in the internal aqueous phase (W₁) and NaCl in the external phase (W₂). In O/W emulsions, oils rich in polyunsaturated fatty acids (PUFAs), such as perilla and sesame, produced smaller droplets, lower viscosity, and more negative ζ-potentials than those rich in monounsaturated fatty acids (MUFAs). These attributes were associated with enhanced saltiness and reduced bitterness. The effects were more pronounced in HIPDEs, where the oil type influenced the KCl encapsulation efficiency (EE) and release behavior. Canola oil showed the highest EE, whereas sesame oil exhibited faster KCl release, thereby modulating the perceived saltiness and bitterness. Headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) identified volatile compounds, including pyrazines, consistent with cross-modal odor-taste interactions related to saltiness enhancement. In vitro digestion revealed that HIPDEs containing PUFA-rich oils, particularly perilla oil, maintained their structural integrity and exhibited controlled droplet disintegration under simulated gastrointestinal conditions. These findings highlight the functional and sensory advantages of PUFA-rich plant oils in sodium-reduced emulsions and inform the development of low-sodium foods with improved palatability and structural stability.