Aggregates of octenylsuccinate oat β-glucan as novel capsules to stabilize curcumin over food processing, storage and digestive fluids and to enhance its bioavailability†
Self-aggregates of octenylsuccinate oat β-glucan (AOSG) have been verified as nanocapsules to load curcumin, a representative of hydrophobic phytochemicals. This study primarily investigated the stability of curcumin-loaded AOSGs over food processing, storage and digestive fluids. Curcumin in AOSGs showed better stability over storage and thermal treatment than its free form. Curcumin loaded in AOSGs stored at 4 °C in the dark exhibited higher stability than that at higher temperatures or exposed to light. Approximately 18% of curcumin was lost after five freeze–thaw cycles. Curcumin in AOSG was more stable than its free form in mimetic intestinal fluids, attesting to the effective protection of AOSG for curcumin over digestive environments. When curcumin-loaded AOSG travelled across mimetic gastric and intestinal fluids, curcumin was tightly accommodated in the capsule, while it rapidly escaped as the capsule reached the colon. Interestingly, the curcumin loaded in AOSG generated higher values of Cmax and area under the curve than did its free counterpart. These observations showed that AOSG is a powerful vehicle for stabilizing hydrophobic phytochemicals in food processing and storage, facilitating their colon-targeted delivery and enhancing their bioavailability.