Molecular mechanism underlying coencapsulating chrysophanol and hesperidin in octenylsuccinated β-glucan aggregates for improving their corelease and bioaccessibility

Abstract

Chrysophanol and hesperidin are natural nutraceuticals that exhibit synergistic bioactivities, but their hydrophobicity limits their applications, and it is unclear whether coencapsulation can improve their solubility and release behaviors. The objective of this work was to coencapsulate chrysophanol and hesperidin by octenylsuccinated β-glucan aggregates (OSβG-Agg) and to reveal how coencapsulation improves their release and bioaccessibility. Mechanisms underlying the hypothesis of beneficial effects in coloading, corelease and bioaccessibility were revealed. The solubilization of OSβG-Agg was due to hydrogen-bonding among β-glucan moieties of OSβG and hydroxyl groups of chrysophanol and hesperidin and hydrophobic interactions among octenyl chains of OSβG and hydrophobic moieties of chrysophanol and hesperidin. Structural analyses confirmed the hypothesis that chrysophanol molecules were nearly embedded deeper into the interior of hydrophobic domains, and most of hesperidin molecules were incorporated into the exterior of the hydrophobic domains of OSβG-Agg due to the strength of these interactions, but they interacted in OSβG-Agg with a dense and compact structure rather than existing in isolation. The combined effects delayed their release and enhanced their bioaccessibility because of dynamic equilibrium between the favorable interactions and unfavorable structural erosion and relaxation of OSβG-Agg. Overall, OSβG-Agg is effective at codelivering hydrophobic phenolics for functional foods and pharmaceuticals.