Films from Oat Spelt Arabinoxylan Plasticized with Glycerol and Sorbitol

The development of packaging films based on renewable materials is an important and active area of research today. This is the first extensive Study focusing on film-forming properties of an agrobiomass byproduct, namely, oat spelt arabinoxylan. A plasticizer was needed for cohesive film formation, and glycerol and sorbitol were compared. The tensile properties of the films varied with the type and amount of the polyol. With a 10% (w/w) ptasticizer content, the films containing glycerol had higher tensile strength than the films containing sorbitol, but with a 40% plasticizer content, the result was the opposite. Sorbitol-plasticized films retained their tensile properties better than films with glycerol during 5 months of storage. The films were semicrystalline with similar crystallinity indices of 0.20-0.26. The largest crystallites (9.5 nm) were observed in the film with 40% glycerol. The softening of films with 40% (w/w) glycerol started at a significantly lower relative humidity (RH) than that of the corresponding sorbitol-containing films. The films with sorbitol also had lower water vapor permeability (WVP) than the films with glycerol. The films plasticized with 100% (w/w) sorbitol had a WVP value of 1.1 g mm/(m(2).d.kPa) at the RH gradient of 0/54%. The oxygen permeability of films containing 10% (w/w) glycerol or sorbitol was similar: 3 cm(3).mu m/(m(2).d.kPa) at 50-75% RH. A higher plasticizer content resulted in more permeable films. Permeation of sunflower oil through the films was not detected. (C) 2009 Wiley Periodicals, Inc. J AppI Polym Sci 114: 457-466, 2009