Optimization and Characterization of Curcumin Loaded in Octenylsuccinate Oat β-Glucan Micelles with an Emphasis on Degree of Substitution and Molecular Weight

The dependence of the curcumin loading capacity (CLC) of octenylsuccinate oat beta-glucan (OSG) micelles on the structural parameters (degree of substitution, DS; molecular weight, M-w) of OSG was unknown and explored in this study. Meanwhile, the curcumin-loaded OSG micelle (COM) was first characterized. The results from response surface methodology revealed that the linear effects of M-w and stirrer input power, as well as the quadratic effect of DS, were significant (p<0.05). The maximum CLC value of the OSG micelle was obtained as 4.21 mu g/mg. Dynamic light scattering showed that the average size and zeta potential of the COM were 308 nm and -10.8 mV, respectively. Transmission electron microscopy and atomic force microscopy evidenced that the COM was elliptical in shape. Fourier transform infrared spectroscopy, differential scanning calorimeltry, and X-ray diffraction revealed that curcumin was loaded in OSG micelles in an amorphous form by interacting with OSG molecules.