Probiotic encapsulation in electrospun polyvinyl alcohol/cellulose acetate hybrid fibers

Probiotic microorganisms are known to be important for health. Although, they have sensitivity to various factors. Encapsulation techniques are used to increase the resistance of probiotics towards different conditions. In this thesis, polyvinyl alcohol (PVA) ̶ cellulose acetate (CA) hybrid fibers (PVA/CA fibers) were produced by using angled dual nozzle electrospinning system. The aim of this study is to produce encapsulation material, resistant to digestive system conditions by using CA. CA was used for the first time for probiotic encapsulation with this project. However, the solvents of CA, may have toxic effects on microorganisms. This undesirable effect was prevented by angled double nozzle electrospinning system to avoid the contact of the solvent with the microorganism. Escherichia coli Nissle 1917 (EcN), which was inoculated into PVA, was encapsulated in hybrid fibers without exposure to the toxic solvent of CA. Firstly, the solutions which were used to produce hybrid fiber, were optimized. Then, EcN was encapsulated into PVA/CA fibers (PVA/CA-EcN fibers). It was observed that the electrospinning process had no significant adverse effect on viability. Encapsulation efficiency was found to be over 90%. Digestive resistant of encapsulated probiotic microorganisms was investigated by in vitro simulation. It was observed that higher viability results were obtained from PVA/CA-EcN fibers, compared to not only free EcN but also PVA/PVA-EcN fibers. It was found that the stabilization of probiotics encapsulated with PVA/CA-EcN fibers could be protected for a long time. The results of the study showed that PVA/CA fibers provided remarkable resistance to digestive system conditions.