Fabrication of Gliadin–Carboxymethyl Chitosan Composite Nanoparticles to Improve the Stability and Antioxidant Activity of Curcumin

The antisolvent precipitation method was employed to synthesize curcumin-loaded gliadin-carboxymethyl chitosan (CMCS) composite nanoparticles (GCC NPs). When the gliadin/CMCS weight ratio was 2:1, the GCC NPs with an ideal negative charge (-27.57 ± 1.07 mV) and the minimum particle size (184.13 ± 5.49 nm) were obtained. With the addition of CMCS, the encapsulation efficiency (EE) of Cur was markedly improved from 77.46 ± 1.54% to 93.88 ± 1.31%. Under various pH values and salt concentrations, the GCC NPs displayed excellent colloidal stability. Specifically, after encapsulation within the GCC NPs, the antioxidant activity of Cur was markedly improved. In ABTS and DPPH assays, the SC₅₀ values of the GCC NPs were 4.98 ± 0.07 µg/mL and 9.86 ± 0.29 µg/mL, respectively. In summary, the GCC NPs would be an effective platform for the delivery of Cur in food and pharmaceutical preparations.