Preparation Of Functional Zein/Polyphenols Fiber Composites And Their Property

Polyphenols are sensitive to heat, pH and light and easily influenced by external conditions. Under normal conditions, their storage period is not very long due to they are easy to be oxidized when exposed to air,therefore their scope of application have been limited. In order to improve the storage stability of polyphenols, zein was selected, and the polyphenols were encapsulated by electrospinning technique. The characteristics of controlled release, antioxidant capacity and antibacterial activity were studied.The proanthocyanidins encapsulated in zein (zein-PA) fibers was via electrospinning technique. The kinetics and antioxidant capacity of PA from zein fibers was investigated by cyclic voltammetry. Circular dichroism was used to investigate the secondary structure change of zein and its influence on the shape of fibers. The addition of PA caused a significant increase inviscosity and made fibers wider. These hydrogen bonds between zein and PA molecules would favor the a-helix change and decrease the ?-folds of zein in electrospinning solutions,leading to a round-shaped tendency of fibers and enhancing the thermal properties slightly.Zein-PA fibers showed high encapsulation efficiency close to 100%, and the encapsulated PA retained its antioxidant capacity in fibers. Zein-PA fibers showed a good controlled release toward PA, and the predominant release of PA from fibers was Fickian diffusion, which could be well described by first-order model and Hixson-Crowell model.The aim of the present study was to evaluate the release kinetics and antibacterial activities of curcumin loaded in zein (zein-CUR) electrospun fibers towards Escherichia coli (E. coli, 8099) and Staphylococcus aureus (S. aureus, ATCC 6538).CUR was successfully loaded in zein fibers by electrospinning technique, and the encapsulation efficiency was close to 100% and the encapsulated CUR still retained its antioxidant capacity. The morphology and size of fibers strongly depended on CUR contents. The interaction between CUR and zein matrix was confirmed to be intermolecular hydrogen bonds, and the addition of CUR caused a slight increase in the Tg of zein matrix. The electrode process of CUR electrooxidation was diffusion-controlled and could be preceded by chemical reaction. The predominant release of CUR from fibers was Fickian diffusion, and First-order model andHixson-Crowell model could well describe this diffusion behavior. The zein-CUR fibers showed good antibacterial activity towards S. aureus and E. coli, and the inhibition efficiency increased with the increase of CUR contents. However, the antibacterial activity towards S. aureus was better than that towards E. coli.