High-speed air circulation preserves curcumin bioactivity and enables pH-dependent intestinal release in oyster-based...

Curcumin exhibits anti-inflammatory potential for inflammatory bowel disease (IBD) dietary intervention, but its thermal sensitivity and low solubility cause degradation in conventional processing. In this work, orthogonal array design L₉(3³) was adopted to optimise high-velocity air circulation (HAC) processing parameters for curcumin-fortified oyster patties, characterized curcumin structure by UV-Vis/FTIR/DSC, validated bioactivity using LPS-induced RAW264.7 cells, and evaluated gastrointestinal targeting through in vitro release. The optimal HAC conditions were 180 °C, 12 min, 2 m/s, with curcumin retention rate of 72.5 ± 1.4% (higher than traditional roasting's < 60%) and stable retention (fluctuation <5%) across 0.1-0.7 g/kg concentrations. UV-Vis/FTIR confirmed curcumin conjugated system integrity with controllable structural perturbations. 0.3 g/kg curcumin inhibited NF-κB pathway (p-NF-κB/NF-κB = 1.75, p-IκBα/IκBα = 2.17) and reduced pro-inflammatory factors/NO release, maintaining >97% cell viability. In vitro release showed <6% gastric release and 61.16% intestinal release at 8 h, realizing pH dependent targeting. The results indicated that HAC technology effectively maintained the structural integrity and bioactivity of curcumin. The oyster cake matrix provided thermal protection for curcumin and achieved pH-triggered intestinal targeted delivery, satisfying the special dietary intervention requirements of IBD patients.