In order to enable the applicability of the essential oil of Lippia origanoides Kunth, increasing its stability and dispersion in aqueous base, were prepared nanogels of chitosan modified with ferulic acid to be used in their encapsulation. The results obtained by FTIR and C SSNMR revealed the formation of CS-FA link in the different synthesized nanogels, while the studied by DLS showed particles with varied sizes and positive charge. A satisfactory encapsulation capacity of the essential oil was obtained for the nanogels. However, the nanogel synthesized with the highest proportion of ferulic acid in relation to chitosan 0.760 g of ferulic acid (CF1) showed the highest encapsulation efficiency of 20%. The results indicate the CF1 nanogel potential to encapsulate important components of the essential oil of L. origanoides, being able to guarantee the constituents, preservation, moreover facilitate the dispersion and release, expanding its use.

No abstract

In this study, a nanogel was developed from a natural polymer, chitosan, to be used in the Lippia origanoides essential oil encapsulation. The encapsulation process was used in order to improve the functional capacity of this essential oil as an antioxidant. To obtain the nanogel, the chitosan was modified with caffeic acid using EDC coupling agent. The obtained material was characterized by FTIR and TGA, revealing the formation of the chitosan-caffeic acid bond. The size, morphology and essential oil amount incorporated to the nanogel were investigated by DLS, SEM and gravimetric analysis, respectively. SEM and gravimetric analysis indicated that oil were efficiently trapped inside the CS-CA matrix, with encapsulation efficiency of 42 ± 2%. The EDL studies showed that the encapsulation of essential oil in the nanogel significantly affected your structure, with a average particle size of 417.26 ± 55.96. After essential oil incorporation into the CS-CA nanogel it was also observed a increase in its antioxidant capacity in terms of elimination of DPPH and ABTS radicals, and ferric reducing antioxidant power (FRAP). The successful development of this CS-CA nanogel loaded with L. origanoides essential oil will lead to a better applicability of this essential oil as an effective antioxidant.

Determinação do Teor de Ácido Ascórbico e Capacidade Antioxidante dos Frutos de Buchenavia tomentosa Eichler Resumo: Neste estudo, cinco soluções extratoras diferentes foram utilizadas para avaliar o teor de ácido ascórbico das polpas in natura e liofilizada dos frutos de Buchenavia tomentosa Eichler. Também foram avaliadas as capacidades antioxidantes da polpa liofilizada por diferentes ensaios. As concentrações de ácido ascórbico encontrados na polpa dos frutos in natura variaram entre 7315,70 e 13272,63, já na polpa liofilizada os teores estiveram entre 1337,67 a 1503,33 mg 100 g-1. O teor de compostos fenólicos totais foi igual a 161,58 ± 24,69 mg de ácido gálico g-1 e o de flavonoides igual a 5,93 ± 0,40 mg de quercetina 100 g-1 de polpa. As atividades antioxidantes obtidas nos ensaios DPPH e FRAP foram de 50,29 ± 0,61 g de polpa desidratada g-1 de DPPH e de 3303,81 ± 50,47 mM de sulfato ferroso g-1 , respectivamente. Em contrapartida, para o sistema β-caroteno/ácido linoleico a amostra comportou-se como pró-oxidante, devido ao elevado conteúdo de ácido ascórbico.