Optimization and Bioactive Properties of Nanoemulsion Formulated with Hemp ( Cannabis sativa L.) Seed Oil and Aloe vera ( Barbadensis miller Stockton) Gel

Abstract The use of nanoemulsions, a nanotechnology technique, is very popular in the food industry to extend the shelf life of foods and preserve their quality. In this study, it was aimed to develop, optimize, and determine the bioactive properties of nanoemulsion containing Aloe vera gel (AVG) and hemp seed oil (HSO) for use in the food industry. Nanoemulsions containing different ratios of AVG (1 %, 2 %, and 3 %) and HSO: Tween 80(T80) (1 : 4; 20, 25, 30 %) were formulated by ultrasonication. Bioactive properties of nanoemulsions were determined by droplet size, polydispersity index (PDI), zeta potential, Transmission electron microscopy (TEM) imaging, Fourier transform infrared spectroscopy (FT‐IR), viscosity, color, whiteness index, turbidity, conductivity, pH, antioxidant (DPPH), and antimicrobial activity analyses. The pH of the nanoemulsions was between 4.74 and 4.88 due to the acidic nature of AVG. PDI was determined in the 0.17 (HA8) range to 0.26 (HA1). According to the FT‐IR spectrum, it was determined that the entire nanoemulsion formulation did not undergo any chemical degradation and their particle sizes (range between 118.9 nm and 170.5 nm) were <200 nm. The small droplet size and PDI values obtained showed that the nanoemulsions had a homogeneous and stable structure in their dispersions. TEM results determined that all nanoemulsions showed a spherical shape, but the structure detected in the HA8 group had a more homogeneous appearance. The antioxidant activity of the nanoemulsions increased depending on the increasing HSO and AVG percentages. Unfortunately, no antibacterial activity of the nanoemulsions was detected against any of the bacterial strains tested. According to the analysis results, it was determined that the best nanoemulsion formulation belonged to the HA8 group containing 3 % Aloe vera gel and 5 % HSO in terms of TEM and PDI analyses.