Various-sourced pectin and polyethylene oxide electrospun fibers

Pectin, a naturally occurring and biorenewable polysaccharide, is derived from plant cell wall tissue and used in applications ranging from food processing to biomedical engineering. Due to extraction methods and source variation, there is currently no consensus in literature as to the exact structure of pectin. Here, we have studied key material properties of electrospun pectin blends with polyethylene oxide (PEO) (1:1, v/v) in order to demonstrate the fabrication of a fibrous and less toxic material system, as well as to understand the effects of source variability on the resulting fibrous mats. The bulk pectin degree of esterification (DE) estimated using FUR (bulk apple pomace (AP) = 28%, bulk citrus peel (CP) = 86% and bulk sugar beet pulp (SBP) = 91%) was shown to inversely correlate with electrospun fiber crystallinity determined using XRD (PEO-AP = 37%, PEO-CP = 28% and PEO-SBP = 23%). This in turn affected the trend observed for the mean fiber diameter (n = 50) (PEO-AP = 124 +/- 26 nm, PEO-CP = 493 +/- 254 nm and PEO-SBP = 581 +/- 178 nm) and elastic tensile moduli (1.6 +/- 0.2 MPa, 437 +/- 0.64 MPa and 2.49 +/- 1.46 MPa, respectively) of the fibrous mats. Electrospun fibers containing bulk AP had the lowest DE, highest crystallinity, smallest mean fiber diameter, and lowest tensile modulus compared to either the bulk CP or bulk SBP. Bound water in PEO-CP fiber and bulk pectin impurities in PEO-SPB were observed to influence fiber branching and mean diameter distributions, which in turn influenced the fiber tensile properties. These results indicate that pectin, when blended with PEO in water, produces submicron fibrous mats with pectin influencing the blend fiber properties. Moreover, the source of pectin is an important variable in creating electrospun blend fibrous mats with desired material properties. (C) 2014 Elsevier Ltd. All rights reserved.