Obtention of Antimicrobial Fibers Type Core/Shell Pla/Pvoh-Lae By Coaxial Electrospinning

Coaxial electrospinning (EC) is a technology that allows the encapsulation of active compounds, such as ethyl lauroyl arginate (LAE), in shell/core structures, in order to develop new antimicrobial materials for food packaging that slow down the release of active compounds and extend the food’s shelf life. For this reason, the objective of this study was to develop antimicrobial fibers shell/core type by EC. Two polymers with different hydrophilic character, polylactic acid (PLA) for the shell and polyvinyl alcohol (PVOH) and LAE for the core, were used to obtain PLA/PVOH-LAE fibers and slow the release of the antimicrobial compound. The morphology of fibers was evaluated by optical microscopy and their thermal properties through thermogravimetric analyses (TGA). LAE release studies were carried out in a fatty food simulant (ETOH 95%), and was compared with the minimum inhibitory concentration (MIC) values of LAE against a gram-positive bacteria, Listeria innnocua. The optical micrographs showed the obtaining of the shell/core structure with an average diameter of approximately 0.6 µm, and the TGA analyses demonstrated the thermal protection of LAE by the shell of the fibers. Released LAE reached the equilibrium state in ETOH 95% during the first 3 hours, maintaining a higher concentration than the MIC value obtained in L. innnocua (10 ppm). The results demonstrate that new packaging materials with antimicrobial activity such as PLA/PVOH-LAE polymeric fibers with a shell/core structure can be obtained through the coaxial electrospinning technique. Keywords: coaxial electrospinning, ethyl lauroyl arginate, fibers, shell/core, food packaging. Resumen El electrohilado coaxial (EC) es una tecnologia que permite encapsular compuestos activos como el etil lauroil arginato (LAE) en estructuras tipo pared/nucleo con la finalidad de desarrollar nuevos materiales antimicrobianos para el envasado de alimentos que ralenticen la liberacion del compuesto y extiendan la vida util del alimento. Por tal razon, el objetivo de este estudio consistio en desarrollar fibras antimicrobianas tipo pared/nucleo mediante EC. Dos polimeros con distinto caracter hidrofilico como el poli (acido lactico) (PLA) para la pared y poli (alcohol vinilico) (PVOH) y LAE para el nucleo se utilizaron para obtener las fibras PLA/PVOH-LAE, y ralentizar la liberacion del compuesto antimicrobiano. La morfologia de las fibras se evaluo mediante microscopia optica y sus propiedades termicas mediante analisis termogravimetricos (TGA). Se realizaron estudios de liberacion del LAE en un simulante de alimentos graso (ETOH 95%), y se comparo con la concentracion minima inhibitoria (MIC) hacia una bacteria Gram positiva Listeria innnocua. Las micrografias opticas evidenciaron la obtencion de la estructura pared/nucleo con un diametro promedio de 0,6 µm aproximadamente, y el analisis TGA demostro la proteccion termica del LAE por la pared de las fibras. El LAE liberado alcanzo el estado de equilibrio en ETOH 95% durante las 3 hr iniciales, manteniendo una concentracion superior a la MIC obtenida para L. innnocua (10 ppm). Los resultados demuestran que nuevos materiales de envase con actividad antimicrobiana como fibras polimericas PLA/PVOH-LAE con estructura pared/nucleo pueden ser obtenidos mediante la tecnica de electrohilado coaxial. Palabras clave: electrohilado coaxial, etil lauroil arginato, fibras, pared/nucleo, envase de alimentos.