Interface behavior, competitive substitution, and saltiness perception of switchable water-in-oil high internal phase emulsions-based delivery carrier for sodium salt regulated by OSA starch

With the increased public awareness of health risks, the development of low-fat and low-salt salad dressings has garnered widespread attention. A switchable delivery carrier for sodium salt, based on water-in-oil high internal phase emulsions (W/O HIPEs) and regulated by octenyl succinic anhydride (OSA) starch, was created. The saltiness perception, physical stability, interfacial property and water-oil distribution of W/O HIPEs were analyzed. Incorporating 2 mg/mL OSA starch in the internal aqueous phase was a key regulatory point to achieve switchable delivery of sodium salt in W/O HIPEs. It was related with the synergistic effect between OSA starch and polyglycerol polyricinoleate (PGPR). The formation of a stronger viscous response interfacial layer, coupled with the reduction of free water mobility, reduced their instability index (0.045). In contrast, the competitive effect between OSA starch (4, 6 mg/mL) and PGPR promoted the formation of the fragile water-in-oil interfacial layers, enhanced the oil mobility and the movement of the droplets, thereby accelerating the droplets aggregation (6.580 μm) and increasing the instability index (0.301). The targeted oral instability of W/O HIPEs mediated by α-amylase contributed to the release of sodium salt and enhanced saltiness perception ( I max ≥5.12). Overall, these findings would be beneficial in developing new low-fat and low-salt alternatives to salad dressings.