Antimicrobial Activity of Edible Electrospun Chitosan/Cellulose Acetate/Gelatin Hybrid Nanofiber Mats Incorporating Eugenol

Antimicrobial nanofiber mats were successfully fabricated via electrospinning. Polymer solutions of chitosan, cellulose acetate and gelatin were blended at a volume ratio of 4:1:5. Eugenol at concentrations of 0 to 10.0% (v/v) was directly incorporated into the mixed polymer solutions. Electrospinning was performed at 23 kV with a flow rate at 0.7 ml/h and collector distance of 10 cm. The average diameters of fibers incorporated with eugenol ranged from 152.32±41.48 to 288.92±77.69 nm. Fibers with larger diameters and junctions appeared when the concentration of eugenol was increased. Eugenol release was observed within 300 min. The burst release of eugenol at 0.1, 0.75, and 1.5% (v/v) reached equilibrium after 60 min while the burst release at 3.0, 5.0 and 10.0% (v/v) continued to increase gradually. The phase transition temperatures of nanofiber mats incorporated with eugenol ranged from 129.69 to 161.84 °C. The thermal characteristic demonstrated that the melting point decreased in accordance with the increase of incorporated eugenol. The nanofiber mats with eugenol at less than 5.0% (v/v) showed better thermostability than mats incorporated with eugenol concentrations greater than 5.0% (v/v). Antibacterial activity was tested against Salmonella Typhimurium and Staphylococcus aureus. The results demonstrated that the edible electrospun CS/CA/Gel nanofiber mats incorporated with eugenol could effectively retard the growth of both bacteria. Our results suggest that eugenol incorporated nanofibers have potential applications as antimicrobial materials in active food packaging, air filtration, antibacterial textiles, wound dressing, drug delivery and others.

Keywords: antimicrobial nanofibers; electrospinning; edible electrospun; eugenol; chitosan

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                                           E-mail: rtepsorn@tu.ac.th