Estefania Júlia Dierings de Souza; Felipe Nardo dos Santos; Juliani Buchveitz Pires; Elder Pacheco da Cruz; Laura Martins Fonseca; Eliezer Avila Gandra; Alvaro Renato Guerra Dias; Elessandra da Rosa Zavareze
ABSTRACT
Encapsulation of essential oils may broaden their application in the food chain by promoting their protection. Thus, starch ultrafine fibers are effective green vehicles to increase the thermal stability of bioactive compounds. The objective of this study was to evaluate the antimicrobial activity of tea tree essential oil (TTEO) and perform its encapsulation in yam starch ultrafine fibers by electrospinning. The TTEO was evaluated by chemical composition, thermal properties, and antimicrobial action against Escherichia coli and Staphylococcus aureus bacteria. The ultrafine fibers containing TTEO were evaluated by morphology, size distribution, water contact angle, Fourier transform infrared (FTIR) spectra, thermal properties, and loading capacity (LC). The main compounds of TTEO were 4-terpineol (49.13%) and α-terpineol (11.46%). The free TTEO presented inhibition zones ranging from approximately 5 to 20 mm for E. coli and S. aureus bacteria. The polymeric solutions presented a maximum electrical conductivity of 3.44 mS·cm−1 and pseudoplastic behavior by rheological measurements. The ultrafine fibers containing TTEO displayed continuous morphology, mean diameters ranging from 187 to 231 nm, and LC ranging from 12.1% to 13.4%. The increase in TTEO concentration in the ultrafine fibers promoted an increase in the contact angle with water, reducing its hydrophilicity. Yam starch ultrafine fibers are a promising structure for the encapsulation of TTEO, increasing its thermal stability for future applications in the food chain.