Optimization of electrospinning parameters for the production of zein microstructures for food and biomedical applications.

Electrohydrodynamic techniques have been focus for the development of structures for encapsulation purposes. Their physico-chemical characteristics confer them significant benefits for food and nutraceutical applications. The study reports the optimization of zein microstructures (electrosprayed beads/electrospun fibers/films). The effect of zein polymer properties (viscosity and conductivity), flow rate, applied voltage and distance tip-collector were investigated. Results by scanning electron microscopy revealed the morphology observed with zein. The importance of chain entanglement for fibers/beads/films formation in the optimum conditions system was evaluated. Compact electrosprayed microbeads with diameters ranging from 0.9 μm to 2.0 μm were obtained for 5 wt.% zein solution. For 30 wt.% zein, uniform smooth electrospun fibers with diameters of approximately 0.60 to 0.75 μm were produced. Films with different characteristics (with more or less homogeneous matrix and more or less bubbles) were also obtained. The developed zein microstructures are potential vectors that might encapsulate bioactive ingredients for functional food, nutraceutical and medical applications.