Electrosprayed WPC/PEO Mats Coated to Fresh Figs

Abstract

Electrohydrodynamic atomization that is also defined as electrospraying is a method of producing mats that are composed of nano- or micro-scaled droplets. Unlike nanofibers that are obtained by electrospinning, the droplets are in spherical forms, and this is the result of the struggle between the applied electrostatic forces and the surface tension of the liquid (meaning polymer solution). This study aims to prepare and characterize electrosprayed biopolymer mats. The 1:2 blend of HWPC (hydrolyzed whey protein concentrate): PEO (poly (ethylene oxide)) is the polymer solution prepared in 2.5% aqueous acetic acid solvent. Physicochemical, morphological and structural analysis are applied to both solution and the electrosprayed mat. Increased viscosity in the protein solution by the addition of PEO enhanced the formation of regular beads observed through SEM images. Image J Visualization and Measurement Software was occupied to determine the diameter distributions of the droplets forming the mat. The mean diameter was found as 1.02±0.55 µm. ATR-FTIR spectroscopy analyses revealed remarkable structural changes in protein and interaction between protein and PEO in the electrosprayed mats. The HWPC/ PEO electrosprayed mat coating revealed one log decrease in the microbial load of fresh figs at the end of fourteen-day storage (4ºC). The findings of the presented research are promising for the application of this electrosprayed biopolymer mat for food coating purposes.