PHYSICOCHEMICAL CHARACTERIZATION OF ASTAXANTHIN-Cu COMPLEXES

Astaxanthin (ASX) is a natural biological antioxidant acceptable as a dietary supplement and food colorant. ASX has unique molecular characteristics which form stable formations in the presence of metal ions. This study aims to analyze the astaxanthin-Cu complex using FTIR, SEM-EDS, and XRD. The synthesis of the complex carried on ratios 1:1, 1:2, and 2:1. Complex formation was determined using UV-Vis spectrum and then confirmed using FTIR. Although the profile spectrum UV-Vis has no differences between ratios, FTIR analysis showed an interaction between ASX with Cu. The SEM-EDS microstructure analysis showed that the ASX-Cu complex is a more regular form than astaxanthin alone. The analysis results based on X-ray diffraction showed that the crystal of astaxanthin, Cu, and each complex had different structures, asymmetric, and atomic arrangements. In conclusion, the ASX-Cu complex with a ratio of 1:1, 1:2, and 2:1 has been successfully made at the incubation time of 5 minutes at 20oC.