Application of nanofibers with jackfruit leaf extract via electrospinning to control phytopathogens in Averrhoa carambola L

An antifungal coating of zein nanofibers with jackfruit leaf extract was successfully elaborated by electrospinning. The nanofibers were characterized based on thickness, tensile test, water vapor permeability, water solubility, differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy, and presumptive identification of some compounds in the extract and fibers with extract by HPLC-Masses. The average diameter of the pure nanofibers was 305 nm and for the nanofibers with extract was 731 nm. An encapsulation efficiency of 72% was obtained. FTIR results demonstrated that the jackfruit leaf extract was successfully encapsulated in the zein fibers and did not show strong chemical interactions with the extract. The TGA analysis showed that the zein fibers offered thermoprotection to the compounds in the extract. Inhibition of mycelial growth and spore germination of jackfruit leaf extract against Cladosporium tenuissimum and Aspergillus sydowii in vitro showed good results which were attributed to the antimicrobial activity of some phenolic compounds in the extract such as caffeic acid, kaempferol 3–O– rutinoside, and catechin. The preventive and curative treatments evaluated with the application of the nanofibers showed a decrease in the severity and incidence in the infected Averrhoa carambola L. fruits. The results indicate the encapsulation of the jackfruit leaf extract, as well as the thermoprotection and release of antimicrobial compounds from this matrix. Graphical Abstract