RESUMO
Salvia Mirzaiani essential oil (SMEO) was extracted using hydrodistillation and its GC-MS analysis identified 54 compounds. SMEO nanoemulsion (SMEO-NE) was produced using ultrasound. Then, gum-based films extracted from Cordia dichotoma containing SMEO-NE were prepared at concentrations of 0 (control), 1, 1.5 and 2% (v/v). Addition of SMEO-NE increased thickness, contact angle and elongation at break of the films. It decreased moisture content, water solubility, ultimate tensile strength, water vapor permeability, percentage of light transmission in the visible and ultraviolet range with a significant change in color factors. Formation of new hydrogen bonds between SMEO-NE and film matrix was confirmed by FTIR. Besides, dynamic mechanical-thermal analysis showed a decrease in storage modulus and glass transition temperature of the films. Electron microscope images showed that presence of SMEO-NE led to changes in microstructure of the films. Furthermore, increasing the concentration of SMEO-NE increased antioxidant and antibacterial activity of the films.
Assuntos
Cordia/metabolismo , Filmes Comestíveis , Emulsões/química , Nanopartículas/química , Óleos Voláteis/metabolismo , Salvia/metabolismo , Antibacterianos/química , Antioxidantes/química , Embalagem de Alimentos , Sequestradores de Radicais Livres , Ligação de Hidrogênio , Listeria monocytogenes/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Microscopia Eletrônica , Permeabilidade , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Vapor , Temperatura , Resistência à TraçãoRESUMO
Kefiran-carboxymethyl cellulose biocomposite films incorporated with Satureja Khuzestanica essential oil were developed and characterized. Results indicated that increase in the concentration of the essential oil increased ultimate tensile strength and contact angle but decreased elongation at break, moisture content and water vapor permeability. It also significantly altered color parameters and the percentage of light transmission in the visible and ultraviolet range. Fourier transform infrared spectroscopy revealed the formation of hydrogen bonds between polymer matrix and essential oil. Scanning electron microscopy showed that the surface structure of the films was homogeneous without porosity. Increase in storage modulus and glass transmission temperature in films incorporated with the essential oil was observed through dynamic mechanical thermal analysis. Moreover, significant increase in antioxidant properties and phenolic compounds were noticed. Ultimately, results obtained from evaluation of antimicrobial characteristics of films indicated their inhibitory effects against Staphylococcus aureus and Escherichia coli bacteria.