A Novel Approach for Solubility and Bioavailability Enhancement of Canthaxanthin Obtained from Dietzia natronolimnaea HS-1 by Canthaxanthin-V-Amylose Complex

In this study, a water dispersible delivery system of canthaxanthin as a lipophilic keto-carotenoid pigment was developed by entrapping microbial canthaxanthin in the hydrophobic inner surface of V-amylose helix. The highest recovery yields of canthaxanthin and V-amylose from complex were observed with 20 mg of canthaxanthin and 400 mg of V-amylose. DLS analysis showed that the hydrodynamic diameter of the particles was reduced by ultrasonication to 244 nm. TEM analysis also demonstrated that particles resemble spherical or oval shape after ultrasonication. The powder dispersion remained stable after 1 month. XRD diffractograms represented the amorph structure of complex despite the crystalline structure of pure canthaxanthin, and DSC curves showed the same melting point of complex and V-amylose, both showing the change of canthaxanthin structure to amorph in the encapsulation process, indicating the complete entrapment of canthaxanthin in V-amylose helices. Oxidation stability analysis of the complex revealed an increase in the oxidation resistance of canthaxanthin. Analysis of both ABTS and DPPH radical scavenging activity by the complex showed that this feature was concentration dependent. According to the obtained results, this method is a promising way to be utilized for expanding the use of canthaxanthin in food and pharmaceutical applications with improved solubility and bioavailability.