Multivariate optimization for the production of OSA-starch microcapsules containing clove and white thyme essential oils: Antifungal potential against penicillium digitatum

Estefania Júlia Dierings de Souza; Felipe Nardo dos Santos; Dianini Hüttner Kringel; Jaqueline Ferreira de Souza; Danielle Tapia Bueno; Amanda Fonseca Leitzke; André Ricardo Fajardo; Eliezer Avila Gandra; Claudio Martin Pereira de Pereira; Alvaro Renato Guerra Dias; Elessandra da Rosa Zavareze

ABSTRACT

The objective of this study was to optimize the conditions for the production of microcapsules based on OSA-starch and clove (CEO)and white thyme (WTEO) essential oils (EOs) obtained by electrospraying. The antifungal activity against the fungus Penicillium digitatum was assessed using both the well diffusion method and volatile release action. The microcapsules were characterized bymorphology, loading capacity (LC) presence of functional groups (FTIR), and thermal properties (TGA). Spherical microcapsuleswere formed in all treatments evaluated, with an average diameter ranging from 0.803 to 1.500 μm. The morphology of the materi-als was not affected by the variation of the solution parameters (ethanol: 20% and 30%, OSA-starch: 40% and 50%, CEO and WTEO,and EO concentration: 0.2% and 0.4%). The LC ranged from 30.6% to 97.9%, and TGA and FTIR analyses for all treatments con-firmed the interaction of EOs with OSA-starch. Microcapsules from OSA-starch with CEO showed greater efficiency in reducingthe mycelial growth of P. digitatum through the release of volatiles. These results serve as a basis for future studies to evaluate thetechnological applicability of these capsules in a food matrix or packaging material for controlling the fungal growth of P. digitatum.

http://dx.doi.org/10.1002/pat.70040