Abstract Electrospun nanofibers from gelatin (G), chitosan (CS), and chitosan-polyvinyl alcohol (CS-PVA) were developed by electrospinning process. Mechanical properties were determined by the tensile test, the elastic modulus values of the nanofibers were G (15.418-34.34 MPa) and CS-PVA (17.44-126.427 MPa). The morphological characterization by SEM revealed that the systems with 15% G and 6% CS-PVA showed morphological homogeneity. Structural characterization by FTIR indicated an interaction among some functional groups of the component. Thermal analysis by DSC and TGA showed degradation temperatures for G (330 °C), CS (210 °C to 370 °C), and PVA (310 °C to 420 °C). The contact angles values denoted the hydrophilic nature of the material. Finally, the antimicrobial assay proved that both 15% G and 7% PVA on the CS-PVA system presented the best antimicrobial effect. The results indicate that the electrospun nanofibers fabricated with G or CS-PVA can be used as wound healing dressings.

Abstract Gray mold in grape clusters caused by Botrytis cinerea, is one of the diseases that most affect the table grape market. To control this disease sulphur dioxide releasing pads (SO2) and systemic fungicides are used, currently in regulatory review. In this work, it was proposed to use an extract of garlic (EHA), allicin, dialyldisulfide (DADS) and dialyltrisulfide (DATS) in volatile form to evaluate the incidence of gray mold on clusters of table grapes of the Flame seedless variety. Treatments were impregnated with cellulose, which allowed the release of the volatile compounds on clusters of grape inoculated with 1x106 spores of B. cinerea/mL. The results showed that the volatile emitted by allicin and DADS had a lower effect than that of EHA and DATS. Those compounds similarly inhibited (P≤0.05) disease development in clusters of grape for 14 days at 4 and 25 °C, showing increased effectiveness at low temperature (4 °C). This is a result of particular relevance in the problematic of this disease that occurs during grape cold storage. The effectiveness of garlic-derived compounds applied in their volatile form opens the possibility to use them as an alternative to the traditional fungicides for controlling post-harvest diseases.

Resumen La pudrición gris en racimos de uva causada por Botrytis cinerea, es la enfermedad que más afectan al mercado de la uva de mesa. Su control es mediante almohadillas liberadoras de dióxido de azufre (SO2) y fungicidas sistémicos, actualmente en revisión regulatoria. En este trabajo se planteó evaluar en forma volátil un extracto de ajo (EHA), alicina, dialildisulfuro (DADS) y dialiltrisulfuro (DATS), sobre la incidencia de pudrición gris en racimos de uva variedad Flame seedless. Los tratamientos fueron impregnados en celulosa, que permitió la liberación de los compuestos sobre los racimos de uva inoculados con 1 x 106 esporas de B. cinerea/mL. Los resultados mostraron que los volátiles emitidos por alicina y DADS tienen menor efecto que el EHA y DATS, los cuales inhibieron de manera similar (P≤0.05) el desarrollo de la enfermedad en los racimos durante 14 días a 4 y 25 °C, presentando mejor efectividad a bajas temperatura (4 °C). Resultado de particular relevancia en la problemática de esta enfermedad, que se presenta durante el almacenamiento en frío de la uva. La efectividad mostrada por los compuestos derivados de ajo, aplicados en su forma volátil, abre la posibilidad de su utilización como una alternativa a los fungicidas tradicionales para el control de enfermedades postcosecha.