Emulsion stability and sensory characterization of coconut oil-based O/W and W/O/W salad dressings for sodium reduction

Reducing sodium while maintaining optimum saltiness perception can be achieved by manipulating emulsion microstructure in high-sodium foods such as dressings. This study evaluated the use of coconut oil–based double emulsions as a strategy to reduce salt in emulsion-based salad dressing. Coconut oil-based salad dressings (COSDs) were produced by incorporating sodium chloride (NaCl) in the inner aqueous phase of water-in-oil-in-water emulsions (COSD-W₁/O/W₂), while conventional oil-in-water emulsions (COSD-O/W) served as controls. COSDs containing 0.15-2.00% NaCl were assessed for their stability during 60 days of ambient storage. Saltiness perception was assessed using the three alternative-forced choice (3-AFC) method, and overall sensory acceptability was determined through an acceptance test. The results showed that the physical and chemical stability of COSDs were dependent on NaCl concentration. Higher salt concentrations increased pH in all formulations, while there were no changes in creaming behaviour throughout storage. Initially, COSD-W₁/O/W₂ showed the highest viscosity at 2% NaCl but was the least viscous at the end of storage. Moreover, COSD-W₁/O/W₂ had significantly (p < 0.05) lower peroxide values compared to COSD-O/W. Regarding sensory outcomes, COSD-W₁/O/W₂ samples were perceived as significantly (p < 0.05) saltier than COSD-O/W, especially at 0.15% NaCl. These findings suggest that incorporating W₁/O/W₂ emulsions into salad dressings could be an effective strategy for sodium reduction.