Nanoencapsulation of food bioactives in supramolecular assemblies based on cyclodextrins and surfactant

Abstract

The bioavailability of poorly soluble food ingredients can be achieved by their encapsulation into the 3D macrocyclic structure or self-assembled surfactant micelles. In this study, the mixed self-assembly of cyclodextrins (CDs) and cationic surfactant, 1-hexadecyl-4-(2-(1-methylpyridin-1-ium-4-yl)vinyl)pyridin-1-ium chloride, was studied by a set of physicochemical methods. It was shown using tensiometry and conductometry that the presence of CDs in the micellar medium of this surfactant increases the critical aggregation concentration. Moreover, NMR spectroscopy and spectrophotometry revealed the interaction between the alkyl tail of surfactant and the internal cavity of CDs. It is interesting to note that in the case of γ-CD and HP-β-CD there was additional binding by the vinyl group of surfactant. The observed patterns of aggregation behavior were confirmed by the method of solubilization of hydrophobic substances. Spectrophotometric monitoring of the solubilization of hydrophobic flavonoids (rutin and quercetin) demonstrated that mixed assemblies enriched with surfactant are capable of binding the flavonoid, while they show poor binding ability towards flavonol compound in the presence of a small amount of surfactant.. Variation of the component ratio in the supramolecular CD–surfactant system also allows adjusting the biological properties. Systems with an excess of CD are less toxic to the cells of test microorganisms, herewith, an increase of the surfactant content in a mixture with CD leads to an increase in both antimicrobial and hemolytic activities. Therefore, when using CD complex-based supramolecular approach for food safety, it is necessary to take into account the toxic properties of the base components of the supramolecular mixture.