Browsing by Subject "Thymol"
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Item Unknown 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, TamerThymol (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.Item Open Access Synthesis and characterization of bio-based benzoxazines derived from thymol(John Wiley and Sons, 2019) Ertaş-Doğan, Yelda; Satılmış, Bekir; Uyar, TamerIn the present study, bio-based benzoxazine resins were synthesized from bio-based phenolic compound; thymol, and three different amines; ethylamine, aniline and 1,6-diaminohexane, and paraformaldehyde by solvent-free condensation reaction. The chemical structures of bio-based benzoxazines; T-ea (thymol, ethylamine), T-a (thymol, aniline), and T-dh (thymol, 1,6-diaminohexane) were characterized by proton nuclear magnetic resonance spectroscopy, Fourier transform infrared (FTIR) spectroscopy, elemental analysis, and high-resolution mass spectrometry. The curing studies of T-ea, T-a, and T-dh bio-based benzoxazines were performed by stepwise thermal treatment at 150, 175, 200, 225, and 250 °C. The polymerization (ring-opening and crosslinking reactions) of T-ea, T-a, and T-dh bio-based benzoxazines was investigated by FTIR spectroscopy. Cure analysis was conducted using differential scanning calorimetry and the changes in thermal properties of the T-ea, T-a, and T-dh bio-based benzoxazine resins and their corresponding thermally crosslinked polybenzoxazines PT-ea, PT-a, and PT-dh were studied by thermogravimetric analyzer. The results indicated that all the thymol-based polybenzoxazines have shown enhanced thermal stability.Item Open Access Thymol/cyclodextrin inclusion complex nanofibrous webs: enhanced water solubility, high thermal stability and antioxidant property of thymol(Pergamon Press, 2018) Çelebioğlu, Aslı; Yıldız, Zehra İrem; Uyar, TamerThe development of novel nanomaterials that provide an efficient encapsulation and protection for the active food additives is one of the main focuses of current research efforts at food application areas. From this point of view, in this study, nanofibrous webs from inclusion complexes (IC) of modified cyclodextrins (hydroxypropyl-β-cyclodextrin (HPβCD), hydroxypropyl-γ-cyclodextrin (HPγCD) and methyl-β-cyclodextrin (MβCD)) and essential oils compound (i.e. thymol) was produced through electrospinning technique. While pure thymol has a highly volatile nature, the volatility of thymol was effectively suppressed by the inclusion complexation and ~ 88-100% (w/w) of thymol was preserved in electrospun thymol/cyclodextrin inclusion complex nanofibers (Thymol/CD-IC NF). The aqueous solubility enhancement for hydrophobic thymol was demonstrated by phase solubility diagram which also suggested the 1:1 M inclusion complexation between thymol and CD molecules. Besides, Thymol/CD-IC NF displayed quite fast disintegration in water compared to poorly water soluble thymol. By inclusion complexation, high temperature stability for volatile thymol was achieved for Thymol/CD-IC NF samples. The loading of thymol in Thymol/CD-IC NF conferred DPPH radical scavenging ability to these nanofibrous webs. So, the Thymol/CD-IC NF have shown antioxidant activity along with enhanced water solubility and high thermal stability of thymol. In brief, encapsulation of essential oil compounds such as thymol in electrospun CD-IC nanofibers can promote its potential application in food and oral-care products by associating the large surface area of nanofibrous webs along with CD inclusion complexation which provides enhanced water solubility and antioxidant property, and high temperature stability for thymol.