Antimicrobial electrospun ultrafine fibers from zein containing eucalyptus essential oil/cyclodextrin inclusion complex

Abstract

The aim of this study was to produce ultrafine fibers from zein incorporated with a complex of eucalyptus essential oil (EEO) and β-cyclodextrin (β-CD) with antimicrobial properties by electrospinning technique. The EEO was characterized by chemical composition and antimicrobial tests against three Gram positive and four Gram negative bacteria. The inclusion complex (IC) was prepared with β-CD and EEO by co-precipitation technique and added at different concentrations in zein polymer solution using aqueous ethanol as solvent. The morphology, thermal properties, functional groups, and antimicrobial activity against L. monocytogenes and S. aureus of the ultrafine fibers were evaluated. The composite membranes containing 24% IC exhibited a greater reduction of growth as compared to the fibers without addition of IC. For L. monocytogenes the growth reduction was 28.5% and for S. aureus it was 24.3%. The electrospun IC-β-CD/EEO composite membranes are promising for use in antimicrobial applications, such as food packaging.

Phytochemical-loaded electrospun nanofibers as novel active edible films: Characterization and antibacterial efficiency in cheese slices

“…Figure 1 and Figure S1 in the Supplementary Material), the loaded fibers had thinner fiber diameters with homogeneous size distributions and the use of an acidic solvent to prepare the starting solutions facilitated the formation of beadless morphologies with smooth surfaces. It is worth mentioning that most of the previous works dealing with zein electrospinning were carried out using ethanolic aqueous solutions that give raise to thicker beaded or flat fibers (Antunes et al, 2017;Silva et al, 2018), while the combination of ethanol and acetic acid used in this work has demonstrated to provide improved fiber morphology, considerably reducing fiber diameter.…”

“…Encapsulation of substances using these techniques is rather straightforward, with generally high encapsulation yields and allowing a sustained release of the encapsulated compounds (Anu Bhushani & Anandharamakrishnan, 2014;Fabra, Lopez-Rubio, & Lagaron, 2016). Several EOs have been already loaded into nanofibers through electrospinning including cinnamon (Wen et al, 2016), thyme (Lin, Zhu, & Cui, 2018), peppermint and chamomile (Huang et al, 2019), clove (Cui, Bai, Rashed, & Lin, 2018), eucalyptus (Antunes et al, 2017), ginger (Silva et al, 2018), chrysanthemum (Lin, Mao, Sun, Rajivgandhi, & Cui, 2019) and orange (Tavassoli-Kafrani, Goli, & Fathi, 2018). Concretely, because of their great abundance and excellent potential, essential oils from bay (Laurus nobilis) and rosemary (Rosmarinus officinalis) have attracted great interest, having major volatile compounds (terpenes, terpenoids, phenols), which can modify cell membrane permeability and integrity of bacteria, thus acting as strong antimicrobial natural cocktails (Okoh, Sadimenko, & Afolayan, 2010).…”

Electrospinning of Essential Oils

“…So far a wide variety of essential oils have been electrospun, including cinnamon [39][40][41][42][43][44], oregano [45][46][47][48], peppermint [44,[49][50][51][52], clove [41,[53][54][55][56][57], thyme [58][59][60][61], lavender [62][63][64], eucalyptus [65], ginger [66], tea tree [67,68], Manuka [68], black pepper [69], and sage [69]. This review focuses on works that report the addition of EOs to polymeric solutions before conducting the electrospinning process.…”

β-Cyclodextrins as Encapsulating Agents of Essential Oils

“…These inclusion complexes are relatively more hydrophilic and larger in size than the non-associated active compound, which helps to increase the retention of the encapsulated substance. They are also very interesting because they can mask undesirable flavors and odors that the encapsulated compounds may present [21,56,72,101,102,[106][107][108][109][110].…”