Encapsulation of water-insoluble polyphenols and β-carotene in Ca-alginate microgel particles produced by the Leeds Jet Homogenizer

Polyphenols and β-carotene are widely studied due to their perceived multiple health functions, but their poor solubility in water inhibits their addition to foodstuffs. This provides a motivation for this study: to entrap these water–insoluble compounds into Ca-alginate microgel particles prepared via a special technique termed the Leeds Jet Homogenizer. Water-insoluble particles of polyphenols and β-carotene were successfully loaded into the microgel particles as revealed by images obtained from confocal laser scanning microscopy (CLSM). Microgel particles were separated via incorporation of magnetic nanoparticles (MNPs) into the microgels and application of a magnetic field or via centrifugation, to quantify the yield, payload, and loading efficiencies. It was found that microgel particle yields improved on introducing these water-insoluble compounds up to 10% to 30%. The payloads of compounds in the particles were only <1.5% but mainly due to the low initial concentrations were used, i.e. 0.5 and 18.5 mM for polyphenols and β-carotene, respectively. The loading efficiencies were considerably high, i.e., between 21 to 58%. In short, the results show firm evidence that useful encapsulation of such water-insoluble compounds within Ca-alginate microgel particles can be achieved via this simple and effective technique.