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Abstracts - Joslaine Jacumazo

Type of the Presentation: Poster

MICROCAPSULES OF CHITOSAN-SDS FOR CONTROLLED DELIVERY SYSTEM OF EUGENOL FOR AGRICULTURAL APPLICATIONS

Joslaine Jacumazo1*, Francisco de Assis Marques1, Rilton Alves de Freitas1 and Beatriz Helena Lameiro de Noronha Sales Maia1

1 Universidade Federal do Paraná – UFPR, Curitiba, Paraná, Brasil;

joslainejacumazo@ufpr.br; tic@ufpr.br; rilton@quimica.ufpr.br; noronha@ufpr.br;

* Correspondence: joslainejacumazo@ufpr.br or joslainej@yahoo.com.br

The Eugenol (4-allyl-2-methoxyphenol) is a natural phenolic compound and is a major component of the essential oils extracted from plants as clove, cinnamon, basil and nutmeg. It exhibits antibacterial, antifungal and insecticidal activity, besides being an excellent repellent. However, it presents sensitivity to light, oxygen and heat, besides being highly volatile and chemically unstable which limites its application. The encapsulation of eugenol can minimize its loss during exposure in different environments1-4. The aim of this work was to evaluate the formation of microstructures through the interaction of the anionic surfactant sodium dodecyl sulfate (SDS) and the cationic chitosan polymer to develop a controlled release system of eugenol and, at a later stage, to apply them to agricultural crops. The particles were characterized by ζ-potential, atomic force microscopy and confocal microscopy and the incorporation efficiency was obtained by ultraviolet–visible spectroscopy. The emulsions were prepared containing the eugenol in the organic phase and in the aqueous phase the SDS. An ultrasonic sonication system (25 kHz and 750 W) was used at 25 °C for 3 min. The SDS solution was prepared at a concentration of 5.0 mmol L-1 and different masses of eugenol were used (0.5, 1 and 1.5 mg). After this stage, the emulsions were subjected to zeta potential analysis by titration with aliquots of chitosan solutions (2, 6 and 10 mg mL-1). The SDS and chitosan were both dispersed in sodium acetate buffer pH 4.63 (0.01 mol L-1). The formed particles were stored in solution at 25 ºC and characterized. From experiments, using ζ-potential was possible to obtain the exact concentration of chitosan to be added and no excess of polymer in the coating medium was observed obtaining stable microstructures. The confocal microscopy and atomic force microscopy images shows the formation of microstructures with rough surface and irregular shape and confirms the electrostatic interaction between chitosan and SDS and thus the confinement of eugenol in the emulsion followed by coating with polymer. The high values of eugenol incorporation efficiency (%) (92.2 ± 1.65, 74.7 ± 1.22 and 76.3 ± 2.31 for 0.5, 1 and 1.5 mg, respectively) proves the system proposed to be suitable. This work presents relevant results concerning the development of microstructures containing eugenol coated with chitosan to act as controlled release systems in agriculture.

Refs.

1. Jirovetz, L. et al., J. Agric. Food Chem.54, 6303–6307, 2006.

2. Marchese, A. et al., Critc. Rev. Microbiol. 1–22, 2017.

3. Choi, M.J. et al., Food Res. Int.42, 148–156, 2009.

4. Kashyap, X. et al., Int. J Biol. Macromol.77, 36–51, 2015.