In order to investigate the incorporation of tannin from barbatimao bark in zein nanofibers obtained by electrospinning, it was studied the effect of addition of different contents of tannin in the properties of zein nanostructured membranes and their relationship with fiber morphology. It was confirmed the interaction occurring between the tannin and zein by thermal and microscopy analysis. Addition of tannins increased the glass transition temperature of the nanofibers, suggesting higher energy input for processing for example. SEM micrographs provided evidence of a homogeneous structure for the nanostructured membranes. X-ray analysis showed the presence of zein crystals in the nanofibers. This ongoing research confirms the possibility of incorporation of barbatimao tannin in the production of bio-nanofibers that will be studied for multi-purpose applications. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.