Production of zein nanofibers using an electrospinning technique for the encapsulation of peppermint (Mentha piperita L.) essential oil

Peppermint is a perennial herb with high inhibitory power against bacteria because its chemical profile contains menthol and menthone. In this research, peppermint essential oil (PEO) was encapsulated in various levels (0, 2.5, 5, and 10% w/v) in nanofibers (NFs) obtained from zein using an electrospinning technique. SEM, XRD, TGA, and FTIR tests were performed to investigate the characteristics of NFs after producing them. Also, the resultant NFs were evaluated regarding encapsulation efficiency (EE) and antimicrobial properties via disc-diffusion against Escherichia coli, Staphylococcus aureus, Bacillus cereus, and Salmonella enterica. The results indicated that the morphology was tubular, uniform, and free bead. Fiber diameter increased on average by increasing the amount of PEO (p<0.05). XRD results showed that PEO was amorphous in electrospun zein NFs. TGA and FTIR analyses confirmed the presence of PEO in the electrospun fibers. In addition, the FTIR spectrum showed that the zein protein changed its secondary structure because of the PEO. The results of EE showed that an increase in PEO concentration caused a relevant rise in EE (P<0.05). The electrospun NFs containing PEO showed antimicrobial properties against the target bacteria. According to the current research, NFs obtained from zein via electrospinning can be applied suitably as a substrate to encapsulate PEO as a hydrophobic component.