Dual natural antioxidant-loaded chitosan-graft-oleic acid micelles by ultrasound-assisted self-assembly: Potential additives for antioxidant active packaging

Natural antioxidants are beneficial additives for active packaging due to their ability to resist oxidative damage. Polymeric micelles are effective in delivering natural antioxidants in aqueous environments. However, individual encapsulation of a single antioxidant may not be sufficient to meet the needs of modern food packaging. A dual natural antioxidant-loaded micellar system (i.e., vitamin E [VE] and curcumin [Cur]) was developed to achieve combined functionality and high loading concentration. Chitosan-graft-oleic acid (CSOA) micelles were employed as carriers to co-encapsulate VE and Cur through a facile ultrasound-assisted self-assembly method. The prepared VE and Cur co-loaded micelles (CSOA/VE/Cur) exhibited a uniform spherical structure with an average particle size of 210.6 nm and a zeta potential of +29.5 mV. Moreover, the co-encapsulation of VE and Cur showed a significant enhancement in both entrapment efficiency, loading capacity and stability as compared to the individual encapsulation of either VE or Cur. In addition, the CSOA/VE/Cur micelles showed improved antioxidant activity than free VE/Cur at the same concentrations, as evidenced by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. Moreover, the micellar materials were utilized to fabricate regenerated cellulose (RC) films with antioxidant properties, highlighting their potential as additives for antioxidant active packaging.