Stigmasterol Stability in Medium Chain Triacylglycerides (MCT)-in-Water Emulsions: Impact of Sodium Dodecyl Sulphate (SDS) Surfactant Micelles

The stability of the health-promoting phytosterols in emulsions can be affected by various factors such as lipid medium, storage time, and temperature. In addition to these well-studied factors, emulsions normally contain excessive amount of surfactant that self-assemble into micelles. However, the potential of these surfactant micelles to alter the stability of phytosterol is unclear. In this study, medium chain triacylglycerides(MCT)-in-water emulsion is used as a model emulsion system to report how surfactant micelles of sodium dodecyl sulphate (SDS) can affect the stability of stigmasterol. Addition of SDS micelles (0.5, 1, and 2 wt%) significantly increases the amounts of stigmasterol and stigmasterol hydroperoxides in the aqueous phase of emulsion. A large proportion of stigmasterol hydroperoxides (up to 64.14%) is solubilized into the aqueous phase although the majority of stigmasterol (>90%) remains in the oil phase. Such different distributions of stigmasterol and its hydroperoxides can be responsible for the increased storage time (19, 27, and 33 d for control, 1 and 2 wt% additional SDS, respectively) of stigmasterol in emulsions stored at 60 degrees C.

Automated summary

The addition of sodium dodecyl sulphate (SDS) surfactant micelles to emulsions can significantly increase the content of stigmasterol, leading to different distributions of stigmasterol and its hydroperoxides, which may contribute to an increased storage time.