Abstract
This study aimed to investigate the physical properties of black cumin oil (Nigella sativa) emulsions at different oil: water (w/w) ratios. Black cumin oil (BCO) emulsions were prepared as 80:20, 70:30, 60:40 (w/w) water in oil using 0.1%, 0.25%, 0.5%, 1%, 2% and 3% (w/w) lecithin by high speed homogenizer. The emulsion capacity, emulsion stability, viscosity, droplet size, texture, and color were determined. The physical properties of BCO emulsions were compared to those of sunflower oil (SFO) and corn oil (CO) emulsions. The emulsion capacities of BCO emulsions (13.6-94.7%) were lower than the emulsion capacities of SFO emulsions (19.1-99.3%). Emulsion capacity, emulsion stability, and viscosity of SFO and CO emulsions increased with the increase of lecithin levels. However, in the BCO emulsions, irregular changes in emulsion capacities, emulsion stabilities, and viscosities were observed as the lecithin ratio increased. As the BCO content decreased in emulsions, L* value increased, and a* and b* values decreased. Heterogeneous distribution of droplet size was observed in BCO emulsions according to microscope images, and the particle size analysis results. Due to the health benefits of the BCO and valuable physical properties of BCO emulsions, they can be used in food or the cosmetic industry alone or as a combination with other vegetable oils.