HPMC-GG microcapsules for co-delivery of mannose and curcumin: enhanced intestinal targeting in functional foods

Polysaccharide-based delivery systems offer significant potential for improving the bioavailability of bioactive compounds in functional foods. Using mannose and curcumin as model bioactives with contrasting solubility profiles, we developed novel hydroxypropyl methylcellulose-guar gum microcapsules (CM-HPMC@GG MPs) via spray-drying to achieve synchronous intestinal-targeted release. The HPMC-GG matrix formed a robust 3D hydrogen-bonded network, enabling amorphous encapsulation of both compounds, as confirmed by FTIR, DSC, XRD, and Raman spectroscopy. Optimized CM-HPMC@GG-1:2 MPs exhibited superior sustained release: mannose followed zero-order kinetics (83.4 % cumulative release at 12 h), while curcumin showed pH-dependent Super Case-II transport (86.6 % intestinal release). Encapsulation efficiencies reached 84.2 % (mannose) and 81.9 % (curcumin), with enhanced thermal stability (55 % curcumin retention at 40 °C/7 days vs. 34 % free curcumin). Molecular dynamics revealed GG-dominated van der Waals/hydrogen bonding as the key mechanism. This work provides a scalable, food-grade platform for co-delivery of bioactives with divergent solubilities, advancing functional food design.