Encapsulation and Binding Properties of Curcumin in Zein Particles Stabilized by Tween 20

This work studies the encapsulation and binding properties of curcumin in zein particles stabilized by Tween 20. The addition of Tween 20 is found to increase the encapsulation efficiency, stability, and radical scavenging ability of curcumin. As Tween 20 concentration (CTween 20) increases from 0 to 0.2 g/L, curcumin encapsulated in zein particles exhibits more pronounced increase in the absorption intensity than that at CTween 20 = 0.2–1.8 g/L, which is consistent with the changes of fluorescence intensity and anisotropy of curcumin. The encapsulation and spectroscopic properties of curcumin are explained by the bindings of curcumin in the hydrophobic cavities and the micellar like Tween 20 aggregates in zein particles, which are closely dependent on Tween 20 concentration. The binding constant results further suggest stronger binding affinity between curcumin and zein particles at CTween 20 above 0.2 g/L.