Production of water-soluble β-carotene micellar formulations by novel emulsion techniques

β-Carotene is one of the most common pigments in nature. β-Carotene can easily suffer degradation processes in presence of light, heat and oxygen. β-Carotene formulations provide protection of the active compound and overcome the low bioavailability due to the low solubility in aqueous media. Moreover, the use of β-carotene as natural colorant in beverages requires an appropriate formulation in order to stabilize the particles of β-carotene in a water suspension and to provide the desired color. This work presents a comparative study of the production water-soluble β-carotene formulations using OSA-starch as carrier material preparing the emulsions by different techniques: Ultrasound emulsification, high-shear emulsification and precipitation from a pressurized emulsion. Formulations of β-carotene with encapsulating efficiencies of 30% and a micellar particle size less than 200 nm were obtained by ultrasound emulsification. Different parameters were investigated as time of application of ultrasound, amplitude, duty cycle and organic-water ratio. By high-shear emulsification, lower encapsulation efficiencies were obtained (below 8%), with micellar particle sizes in a similar range as with ultrasound emulsification (less than 240 nm). And regarding the precipitation from a pressurized emulsion, the encapsulation efficiencies achieved were much higher (70-80%), but micellar particle sizes increased to 400 nm.