Emulsion templated microencapsulation of dandelion (Taraxacum officinale L.) polyphenols and β-carotene by ionotropic gelation of alginate and pectin

• Microencapsulation procedure by ionic gelation of emulsions established.
• Simultaneous entrappment of polyphenols and ß-carotene achieved.
• Reinforcement with whey proteins preserved microbead’s spherical properties.
• Higher encapsulation efficiency of hydroxycinnamic acids observed.
• Alginate in combination with whey proteins - the optimal carrier system.

This research underlines the potential of employing emulsion/internal gelation encapsulation in alginate and pectin hydrogels for the simultaneous delivery of hydrophilic (polyphenols from dandelion (Taraxacum officinalis L.) extract) and lypophilic (β-carotene) compounds. The approach of reinforcing alginate and pectin hydrogels by whey proteins and hydroxypropyl methylcellulose (HPMC) as the carriers for the design of microencapsulated delivery systems was also evaluated. Comprehensive characterization of the morphological properties, particle size, encapsulation efficiency, interactions and release in gastrointestinal conditions was achieved. A simple and effective procedure based on the ionic gelation of emulsions for microencapsulation of polyphenols and β-carotene was developed, allowing formulation of micro-sized particles ranging ≤800 μm, which retained their spherical morphological properties upon drying. Incorporation of whey proteins and HPMC in the alginate gel contributed to better encapsulation parameters i.e. the morphological properties and encapsulation efficiency in relation to plain alginate particles. The combination of alginate with whey proteins as the carrier matrix arised as the optimal delivery system, owing to its regular, spherical shape, high encapsulation efficiency of total polyphenols (77,35%) and very good retention of hydroxycinnamic acids (89,14%), while the binary mixture of alginate and HPMC as the carrier enabled the best (prolongued) release profile of these compounds from the formulated microparticles in simulated gastrointestinal fluids.

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