Estabilidade e dinâmica do complexo de inclusão ácido transcinâmico/β-ciclodextrina em ambientes que simulam matrizes alimentares

Abstract

The formation of inclusion complexes with cyclodextrins represents a promising strategy to enhance the stability and applicability of bioactive compounds with low solubility in aqueous media. In this study, the inclusion complex formed between transcinnamic acid and β-cyclodextrin was investigated, with emphasis on evaluating its behavior under conditions that simulate food matrices. The complex was synthesized in aqueous medium to obtain a 1:2 molar ratio complex and characterized by ultraviolet-visible absorption spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR), proton nuclear magnetic resonance spectroscopy (¹H NMR), and thermal analyses (TGA/DSC). The spectroscopic results indicated the formation of the inclusion complex, mainly evidenced by the occurrence of a hypochromic effect and slight changes in the absorption profile of trans-cinnamic acid, consistent with its insertion into the β- cyclodextrin cavity. The stability of the system was evaluated by spectroscopic monitoring of the complex and control physical mixtures in the presence of components commonly found in foods, including sodium chloride, sucrose, citric acid, and ascorbic acid. The samples were monitored over 48 hours by UV-Vis spectroscopy, allowing the observation of changes associated with the influence of these components on the system equilibrium. The results indicated that the composition of the medium exerts a significant influence on the spectroscopic behavior of the complex, suggesting modifications in the intermolecular interactions responsible for its stability. These findings contribute to the understanding of the performance of β-cyclodextrin-based systems in multicomponent media and provide support for future applications of transcinnamic acid in food formulations and encapsulation systems.