Electrospun Zein Fibers as Carriers to Stabilize (-)-Epigallocatechin Gallate

• Published in: Journal of food science 2009-04, Vol.74 (3), p.C233-C240
• Main Authors: Li, Y, Lim, L.-T, Kakuda, Y
• Format: Article
• Language: English
• Subjects: (−)-epigallocatechin gallate; Animal, plant, fungal and microbial proteins, edible seaweeds and food yeasts; aqueous solutions; Biological and medical sciences; catechin; Catechin - analogs & derivatives; Catechin - chemistry; chemical concentration; Corn; diameter; Drug Stability; electrical treatment; Electricity; electrospun ultrafine fibers; encapsulation; epigallocatechin; Ethanol; fiber aging; Food industries; Food science; Fourier transform infrared spectroscopy; Fourier transforms; Fundamental and applied biological sciences. Psychology; green tea; Hydrogen Bonding; Hydrogen bonds; Hydrophobic and Hydrophilic Interactions; hydrophobicity; Microscopy, Electron, Scanning; physicochemical properties; phytochemicals; plant products; plasticization; polyphenols; protein products; Proteins; Scanning electron microscopy; solubility; solubilization; Solutions; Spectroscopy, Fourier Transform Infrared; Spectrum analysis; storage quality; Studies; swelling (materials); Tea - chemistry; Water; water treatment; zein; Zein - analysis; Zein - chemistry; Zein - ultrastructure; zein protein
• ISSN: 0022-1147; 1750-3841
• DOI: 10.1111/j.1750-3841.2009.01093.x

In this study, a method was developed for continuous electrospinning of ultrafine corn zein protein fibers with diameters ranging from 150 to 600 nm. Fiber-forming solutions with various zein concentrations (10% to 30%, w/w) and aqueous ethanol concentrations (60% to 90%, w/w) were electrospun at 15 and 20 kV. Scanning electron microscopy results showed that the morphology of zein fibers was affected by aqueous ethanol concentration, zein concentration, and the applied voltage. The optimal condition for forming bead-less fibers was found to be 20% protein, 70% alcohol, and 15 kV. The zein fibers resisted solubilization in water, although swelling and plasticization were apparent after the water treatment. The efficacy of zein fibers was tested for stabilization of a green tea polyphenol, (-)-epigallocatechin gallate (EGCG), by incorporating the EGCG in zein fiber-forming solutions. Freshly spun fibers were less effective at immobilizing the EGCG upon immersion in water (82% recovery) as compared to fibers that were aged at 0% relative humidity for at least 1 d (>98% recovery) before water immersion. Fourier transform infrared spectroscopy studies demonstrated that hydrogen bonding, hydrophobic interactions, and physical encapsulation are the major contributors to the stabilization of EGCG in zein fibers in water.