Interaction of Curcumin and Bixin with β-Cyclodextrin: Complexation Methods, Stability, and Applications in Food

This work aimed to compare methods for the formation of complexes of bixin and curcumin with P-cyclodextrin (beta-CD) and to evaluate the stability of the complexes formed by these methods and their food applications. The stoichiometric relationship between curcumin and beta-CD was 1:2 and that between bixin and beta-CD was 1:1. Curcumin-beta-CD and bixin-beta-CD complexes formed by kneading, coprecipitation, and simple mixing were evaluated by differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), or nuclear magnetic resonance (NMR-H). For both curcumin and bixin, the best method of complexation was coprecipitation. Complexation of colorants with beta-CD promoted an intensification of color and increased water solubility; however, stabilization in the presence of light occurred only for bixin. Application of curcumin-beta-CD in cheese and yogurt and bixin-beta-CD in the curd did not alter the initial characteristics of the products, which were sensorialy well accepted. Therefore, the complexation of these natural colorants with beta-CD favors their use in low-fat foods, broadening the field of industrial application.