Structural elucidation of Gluten/Zein nanofibers prepared by electrospinning process: Focus on the effect of zein on properties of nanofibers

Abstract

In this study, gluten/zein (G/Z) blends were electrospun with acetic acid as a solvent. The effects of zein content on the morphology, structure and properties of assembled gluten nanofibers were investigated. G/Z nanofibers were found to have diameters ranging from 209 nm to 462 nm, with smooth surfaces for ratios of 100:0 and rough surfaces for ratios of 30:70. The water contact angle (WCA) > 90 showed that mixed fibers were hydrophobic. SDS-PAGE showed that both proteins were present and were evenly distributed in G/Z nanofibers. The number of high molecular weight molecules decreased and the amount of low molecular weight molecules increased as the zein to gluten ratios increased. Nanofibers with α -helix structures were confirmed by FTIR, XRD, and CD analyses. The α-helix structure increased with increasing zein to gluten ratio in nanofibers, which also increased the characteristic of crystallinity and hydrophobicity. The characteristics of a miscible blend were confirmed by the single glass transition temperature (Tg) seen in the DSC thermograms of the G/Z nanofibers. With a decrease in the amount of zein in the nanofibers, the Tg dropped from 177.7 to 162 °C indicating that the mixed fibers were more flexible compared to the pure zein fiber.