Electrospun zein fibers as carriers to stabilize (-)-epigallocatechin gallate.

摘要

In this research, a method was developed to continuously electrospin zein-ethanol polymer solutions into ultrafine zein fibers. Scanning electron microscopy results showed that the morphology of zein fibers was affected by aqueous ethanol concentration, zein concentration, and the applied voltage. The electrospun zein fibers were tested to encapsulate (-)-epigallocatechin gallate (EGCG), a green tea polyphenol, under optimal electrospinning conditions. Zein fibers aged at 0% RH for 1 day were found to achieve an enhanced EGCG retention (> 98%) in fibers when they were submerged in water. Fourier transform infrared spectroscopy results showed that hydrogen bonding and hydrophobic interactions were the major contributors involves in the stabilization of EGCG in zein fibers. The stability of EGCG in various aqueous solutions (pH 4 - 9, 4 - 100°C) was evaluated by using high performance liquid chromatography to determine the kinetics of degradation and epimerization reactions of EGCG. Pseudo first-order degradation kinetic models were developed for both reactions, of which the rate constants increased as the temperature and pH increased. Overall, the electrospun zein fibers enhanced considerably the stability of EGCG. Potentially, the electrospun zein fibers may be used as a carrier to stabilize the fortified EGCG in food.