A mechanistic study of water-in-fat-in-water high internal phase double emulsion system with various fat types

This study investigated the effects of different fat types on the physicochemical properties and the saltiness perception of water-in-fat-in-water high internal phase double emulsions (W 1 /F/W 2 HIPDEs) containing 80% primary emulsion (W 1 /F). Sodium chloride was added to the internal aqueous (W 1 ) phase, with four different oils (canola, olive, coconut, and palm oil) mixed with palm stearin in ratios of 4:6, 5:5, 6:4 (w/w) to fabricate the spreadable the W 1 /F/W 2 HIPDEs. The results demonstrated that emulsions with higher unsaturated fatty acids (UFA) content, such as canola and olive oils, exhibited larger droplet sizes, faster inner water release, and high spreadability, which in turn enhanced saltiness perception. Conversely, emulsions with saturated fatty acid (SFA)-rich oils, such as coconut and palm oil, formed smaller droplets, leading to lower spreadability and reduced saltiness intensity. Viscosity exhibited non-Newtonian behavior and was more influenced by LCFA than by SFA. Principal component analysis highlighted the relationship among fatty acid composition, physicochemical properties, and saltiness perception. Consequently, the physicochemical, structural, and rheological properties influenced the saltiness perception that the emulsions with canola and olive oil had high scores for salty taste intensity. Overall, this study provides insight into the effects of fat type on the physicochemical properties and saltiness perception of W 1 /F/W 2 HIPDEs, which could benefit the development of tailored emulsion-based food products. • The fatty acid composition determined physicochemical properties of the emulsions. • Droplet size effected the release of NaCl in the double emulsion system. • The emulsions with coconut and palm oils formed firmer textures. • The emulsions with canola and olive oils had high saltiness intensity.