Binding, stability, and antioxidant activity of curcumin with self-assembled casein–dextran conjugate micelles

ABSTRACTThis work studied the potential of self-assembled micelles of casein–dextran conjugates (CD) as a protective carrier for bioactive curcumin. CD was prepared through the Amadori rearrangement of the Maillard reaction. In casein micelles and CD micelles, the addition of curcumin can quench the intrinsic fluorescence of casein gradually. According to the double logarithm equation, the binding constants were determined as 3.9 × 104 and 1.8 × 105 M−1 for the binding of curcumin with casein micelles and CD micelles, respectively. The higher affinity of hydrophobic binding of curcumin with CD micelles was ascribed to the more hydrophobic and compact structure of casein core surrounded by the hydrophilic dextran shell, which was supported by the fluorescence spectrum and fluorescence anisotropy of curcumin. Furthermore, CD micelles were found to be superior to casein micelles for improving the stability and radical scavenging activity of curcumin.