Encapsulation of cannabidiol in hemp seed oleosomes

Oleosomes are natural lipid droplets that can be extracted intact from oil seeds, forming oil/water emulsions. Their lipid cores, surrounded by a monolayer of phospholipids and proteins, make oleosomes suitable as carriers of hydrophobic bioactive compounds like cannabidiol (CBD). As CBD is crystalline at room temperature, it first has to be liquified to allow better encapsulation. This was done by heating (80 °C for 4 h) or by pre-solubilizing CBD in ethanol and then the liquified CBD was mixed with oleosome dispersions for the encapsulation. Both methods exhibit good encapsulation efficiency, but the results were significantly influenced by the ratio of CBD to lipid contents, regardless of the encapsulation method applied. At higher concentrations of CBD relative to that of the lipid in the oleosomes, the encapsulation efficiency decreased as saturation was attained. Moreover, the in vitro digestion analysis was conducted to investigate the potential of oleosomes as carriers to transport CBD. The relatively slow and steady release of CBD from oleosomes indicates that oleosomes are a slow-release carrier for hydrophobic functional ingredients. An important finding is that the encapsulation and in vitro digestive properties of the oleosomes remain unaffected by the presence of CBD, heating treatment or ethanol, which could bring more opportunities for the applications of oleosomes as carriers in various fields.