Encapsulation of Cumin essential oil in zein electrospun fibers: Characterization and antibacterial effect

In this work, electrospinning was applied to encapsulate the Cumin essential oil in zein electrospun fibers. Initially, the Cumin essential oil was obtained and characterized by GCMS and subsequently incorporated in 27% zein solution at 0, 2.5, 5, 10, and 20% (v/v) concentrations. The SEM and Image-J results showed that encapsulation of Cumin essential oil increased the diameter of zein electrospun fibers from 459 to 855 nm for 0% and 20% loaded electrospun fibers, respectively. The 3D-images of topographic surface of zein electrospun fibers was studied using AFM, and indicated that their morphology were in tubular shapes. The XRD was applied to study the physical structure of loaded electrospun fibers, and the XRD diffaractograms indicated the amorphous structure of electrospun fibers. The DSC thermograms indicated that encapsulation of Cumin essential oil increased the thermal stability of zein electrospun fibers. The FTIR spectra indicated the interaction between zein and Cumin essential oil and FTIR spectra also indicated that adding Cumin essential oil to the electrospun fibers affected the secondary structure of zein protein. The mechanical properties evaluation of electrospun fibers indicated that tensile strength increased with increasing Cumin essential oil from 0.28 (MP) to 3.55 (MP) for 0% and 20% loaded electrospun fibers. BET analysis was used to measure pore size of fibers. The obtained pore sizes were 7, 7.5, 8, 11, and 13 nm for 0, 2.5, 5, 10, and 20% loaded electrospun fibers, respectively. Antibacterial test was carried out by disc diffusion method, and results shown that Cumin essential oil loaded fiber mats inhibited the growth of S. aureus and E. coli , B. cereus , and S. enterica . According to results of this work, Cumin essential oil loaded fibers can be considered as an active packaging to be applied in packages of various foods such as cheese, meat and some other food products.