Development of water-soluble β-carotene formulations by high-temperature, high-pressure emulsification and antisolvent precipitation

β-carotene is one of the most common pigments in nature. The application of β-carotene as natural colorant in food and nutraceutical products requires an appropriate formulation in order to protect the active compound from degradation and overcome the low bioavailability due to a low solubility in aqueous media. This work presents a study of the formulation of β-carotene using four different modified n-octenyl succinate (OSA) starches as carrier materials by precipitation from a pressurized ethyl acetate-in-water emulsion. The best results, with encapsulation efficiencies of 70–80% and particle sizes in the sub-micrometer range, were achieved using a OSA-starch refined from waxy maize at concentrations of at least 100 g L−1. Moreover, experiments using ethanol instead of ethyl acetate as organic solvent have been carried out in order to assess the influence of the emulsification, solvent displacement and antisolvent precipitation processes on product characteristics. Equivalent particle sizes were obtained in experiments with ethanol, but with encapsulation efficiencies below 40%, indicating that the formation of an emulsion template is essential in order to achieve a high encapsulation efficiency, while particle sizes are determined by antisolvent precipitation processes.