Recovery and encapsulation of Dunaliella salina β-carotene through a novel sustainable approach: Sequential application of an ionic liquid as naturally-derived solvent and emulsifier

Dunaliella salina is a promising source of β-carotene, widely employed in the food industry. This study aimed to evaluate the sequential application of the Ionic Liquid (IL) cholinium oleate as an extraction solvent for D. salina β-carotene recovery and, sequentially, as emulsifier for emulsion-based products obtained therefrom. The IL was evaluated regarding its ability to permeabilize the cells and recover β-carotene at different temperatures (25-65 °C) and IL concentrations (0-46%). The use of the IL as solvent greatly improved β-carotene recovery (>84%). The IL already present in the obtained extracts loaded with recovered β-carotene was sequentially used as emulsifier in the production of nanoemulsions (NE). NE presented a β-carotene entrapment efficiency of 100% and were kinetically stable for 30 days and presented droplet size, size distribution, and ζ-potential of 220 nm, 0.21, and -67 mV, respectively. These results indicate that using IL sequential as solvent and emulsifier has potential applications in the food industry.