Browsing by Subject "Zein"

Now showing 1 - 3 of 3

Open Access
Antibacterial electrospun zein nanofibrous web encapsulating thymol/cyclodextrin-inclusion complex for food packaging
(Elsevier, 2017-10) Aytac Z.; Ipek, S.; Durgun, Engin; Tekinay, T.; Uyar, Tamer
Thymol (THY)/γ-Cyclodextrin(γ-CD) inclusion complex (IC) encapsulated electrospun zein nanofibrous webs (zein-THY/γ-CD-IC-NF) were fabricated as a food packaging material. The formation of THY/γ-CD-IC (1:1 and 2:1) was proved by experimental (X-ray diffraction (XRD), thermal gravimetric analysis (TGA), 1H NMR) and computational techniques. THY/γ-CD-IC (2:1) exhibited higher preservation rate and stability than THY/γ-CD-IC (1:1). It is worth mentioning that zein-THY/γ-CD-IC-NF (2:1) preserved much more THY as observed in TGA and stability of THY/γ-CD-IC (2:1) was higher, as shown by a modelling study. Therefore, much more THY was released from zein-THY/γ-CD-IC-NF (2:1) than zein-THY-NF and zein-THY/γ-CD-IC-NF (1:1). Similarly, antibacterial activity of zein-THY/γ-CD-IC-NF (2:1) was higher than zein-THY-NF and zein-THY/γ-CD-IC-NF (1:1). It was demonstrated that zein-THY/γ-CD-IC-NF (2:1) was most effective in inhibiting the growth of bacteria on meat samples. These webs show potential application as an antibacterial food packaging material.
Open Access
Carvacrol loaded electrospun fibrous films from zein and poly(lactic acid) for active food packaging
(Elsevier B.V., 2018) Altan, A.; Aytaç, Zeynep; Uyar, Tamer
The composite fibrous films were developed from zein and poly(lactic acid) (PLA) by incorporating carvacrol at three different concentrations (5, 10 and 20%) using electrospinning. The morphology and size of fibers obtained from both zein and PLA were affected by the level of the incorporated carvacrol. The Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA) results showed that carvacrol was encapsulated in electrospun zein and PLA fibers. The antioxidant activity of carvacrol loaded zein fibers ranged from 62 to 75%, while antioxidant capacity of PLA fibers varied from 53 to 65% for 5-20% carvacrol content. The composite fibrous films showed a sustained diffusion controlled release behavior. Preliminary studies on whole wheat bread samples showed that carvacrol loaded electrospun zein and PLA fibers are able to preserve bread samples, indicating that they are good candidates for active food packaging applications to extend the shelf life of whole wheat bread.
Open Access
Electrospinning of cyclodextrin functionalized nanofibers and their applications
(2016-08) Aytaç, Zeynep
Electrospinning is a widely used versatile method to produce nanofibers with high surface to volume ratio and porous structure. Owing to the unique properties, electrospun nanofibers are of great importance as a carrier matrix for drugs; antioxidant, and antibacterial agents, flavour/fragrances. Though polymers are material of choice for producing electrospun nanofibers, it is likely to obtain nanofibers from low molecular weight molecules. Cyclodextrin (CDs) are intriguing molecules having the capability of forming inclusion complex (IC) with numerous guest molecules such as drugs, food additives, flavour/fragrances, antioxidant and antibacterial agents. Therefore, CD-ICs enhance solubility, reduce volatility, and provide controlled release of the guest molecules. Integrating CD-ICs with electrospinning opens a new door to produce remarkable materials. In this thesis, nanofibers containing CD-ICs of bioactive agents including antioxidant/antibacterial and flavour/fragrance molecules were produced via electrospinning technique. Firstly, CD-ICs of antioxidant/antibacterial compounds (gallic acid, α-tocopherol, quercetin, and thymol) were synthesized and then, added into polylactic acid or zein solutions to produce CD-IC incorporated electrospun polymeric nanofibers. Afterwards, the release behavior, antioxidant and antibacterial activity of these nanofibers were investigated. In addition, the potential use of these nanofibers as active food packaging and delivery material was revealed by packing meat samples by these nanofibers. Secondly, electrospun nanofibers were developed as a releasing material from CD-ICs of volatile flavour/fragrance molecules (geraniol, limonene, and linalool) without using polymeric matrix. The preservation of volatile compounds is shown to be possible to a great extent with antibacterial CD-IC nanofibers. Furthermore, the shelf life of flavour/fragrance molecules has been enhanced at least 50 days by CD-IC nanofibers. Finally, for the first time in the literature core-shell nanofibers were designed by using CD-IC of curcumin, an antioxidant molecule and polylactic acid solutions as core and shell, respectively. The ability of core-shell nanofibers as a drug delivery carrier was suggested by release and antioxidant activity tests. To conclude, CD-IC incorporated electrospun nanofibers produced by three different approach is shown to be used as efficient material for various applications particularly for food packaging and drug delivery.