Nanoencapsulamento de vitamina c obtida de suco de camu-camu (Myrciaria dubia) concentrado por nanofiltração: estudo da estabilidade, liberação controlada e potencial de aplicação tecnológica

Abstract

This study aimed to develop and characterize nanoencapsulation systems containing vitamin C from camu-camu (Myrciaria dubia) juice concentrated by nanofiltration, with the purpose of improving its stability and evaluating its controlled release. The juice was subjected to nanofiltration in a tangential-flow system, and the concentrated extract was subsequently incorporated into polymeric formulations based on xanthan gum and gum arabic, Brazil nut oil, and Tween 80 using high-pressure homogenization. Initially, four formulations were evaluated: blank xanthan gum, xanthan gum containing extract, blank gum arabic, and gum arabic containing extract. These formulations were characterized by dynamic light scattering, zeta potential, and transmission electron microscopy, whereas the extract-containing formulations were subjected to photostability assays. Among the nanofiltration conditions evaluated, the combination of 14 bar and 400 rpm resulted in a 66.19% increase in vitamin C content. The formulations showed mean hydrodynamic diameters ranging from 136.6 to 149.0 nm, within the submicrometric range. The xanthan gum formulation containing extract showed a mean hydrodynamic diameter of 136.6 nm, a PDI of 0.212, and a zeta potential of −39.6 mV. The micrographs revealed differences in morphology and dispersion among the systems, with visually more homogeneous particles in the xanthan gum formulation containing extract. In the photostability assays, this formulation showed the best performance among the evaluated systems, retaining 96.34% of vitamin C under white light and 93.55% under ultraviolet radiation. Considering the overall performance observed and the time available to complete the analyses, the xanthan gum formulation containing extract was selected for the subsequent stages of the study. Therefore, infrared spectroscopy, apparent encapsulation efficiency determination, and controlled release testing were primarily conducted using this formulation. FTIR analysis revealed bands consistent with possible interactions between the extract constituents and the xanthan gum matrix, without independently confirming encapsulation. The apparent encapsulation efficiency was estimated at 92 ± 5%. After 96 hours, the concentration detected in the receptor medium reached 57.08 mg/100 mL, corresponding to the reported release of 9.30% according to the original calculation procedure. The results indicate that the xanthan gum formulation has potential for protecting and modulating the release of vitamin C from camu-camu in functional foods, nutraceuticals, and cosmetics, subject to further studies on stability, safety, and performance.