Hemp seed oil nanoemulsion with Sapindus saponins as a potential carrier for iron supplement and vitamin D

Vitamin D3 and iron are important components of a balanced diet. Supplementing meals with these is essential to support the recovery of humankind’s malnutrition. It is necessary to develop effective delivery systems to ensure the high bioavailability of these hydrophobic components. For this purpose, emulsions were prepared based on hemp seed oil and with soap nut extract (Sapindus mukorossi fruits) as a natural emulsifier. To characterize the differences in the properties of the emulsions depending on the content of the oil phase and the emulsifier, measurements were performed to determine the following parameters: the color characteristics, transparency of the samples, infrared spectrum, particle size distribution, polydispersity of the system, and the rheological properties of the emulsions. The results showed that the highest stability was observed in systems with a relatively low oil concentration, i.e., 1%. These samples also had an average particle size not exceeding 200 nm. In turn, the low oil content significantly reduced the dynamic viscosity of the emulsions. At the same time, microscopic observations indicated that the presence of an oil phase was advantageous, not only because of the possibility of providing vitamin D but also because of the high hydrophobicity of the iron particles. Therefore, the realized research made it possible to identify the optimal emulsion composition. The created system can find applications in delivering dietary supplements such as vitamin D3 and iron by providing high dispersion of components and high stability.