Encapsulation of saffron and rose essential oils by single and double emulsion: A review of recent advances

Emulsions consist of two immiscible liquids, typically oil (O) and water (W), stabilized by emulsifiers. They include two main types: Single emulsions (SEs, O/W or W/O) and Double emulsions (DEs, W/O/W or O/W/O). Saffron and rose are two types of essential oils (EOs) with unique functional properties, such as antioxidant and antimicrobial activity, therapeutic properties, and distinctive aromas, which are widely used in the food and pharmaceutical industries. However, the bioavailability, stability, and effective delivery of these oils can be challenging due to their volatility and hydrophobic nature. This is where emulsions, specifically single- and double-emulsions, come into play as potential vehicles for their application. The outcomes of recent research studies showed that the bioavailability, stability, and delivery efficiency of these essential oils can be significantly improved by using emulsions. Double emulsions offer a more satisfying approach than single emulsions, particularly beneficial for the encapsulation of saffron and rose essential oils. Encapsulation within a double emulsion can protect essential oils from oxidation and enhance their stability. The main advantage of these delivery systems is the simultaneous delivery of antioxidant (saffron) and antimicrobial (rose) compounds, which can exhibit synergistic effects. This structure allows for a controlled and sustained release, maintaining their aromatic properties and therapeutic effects over time, which is particularly advantageous in food and cosmetic formulations.