Nanoparticles of betalamic acid derivatives with cyclodextrins. Physicochemistry, production characterization and stability

Abstract

The use of betalains as bioactive compounds has been widely investigated. However, their use as a functional food requires a more exhaustive study because of their photosensitivity and poor stability. For this reason, this works studies the stabilization of two highly bioactive betalain derivatives, phenylethylamine-betaxanthin (Ph- Bx) and indoline-betacyanin (In-Bc) by nanoencapsulation in natural a modified cyclodextrins (CDs). Methyl- β-CD (Mβ-CD) showed the best results for Ph-Bx while Hydroxypropyl-β-CD (HPβ-CD) was better in the case of In- Bc. In addition, the effect of pH and temperature on encapsulation was studied finding that the encapsulation constant (KF) value increased as the pH decreased in the case of Ph-Bx but not in the case of In-Bc. The KF decreased as the temperatures increased. The thermodynamic parameters, ΔH◦, ΔS◦ and ΔG◦, were also calculated. Molecular docking provided further insight into how the different interactions influenced the encapsulation constant. The results show that the presence of CDs during the biotechnological synthesis of Ph-Bx and In- Bc increased production by 51 and 26%, respectively, and also increased the stability of both derivatives. This study represents a first step towards increasing the production of this type of compound for introduction into functional foods.