Effects of extrusion and glycerol content on properties of oxidized and acetylated corn starch-based films

• Published in: Carbohydrate polymers 2012-01, Vol.87 (1), p.707-712
• Main Authors: Yan, Qianqian, Hou, Hanxue, Guo, Pei, Dong, Haizhou
• Format: Article
• Language: English
• Subjects: Applied sciences; Biodegradable film; Biological and medical sciences; biopolymers; corn; Exact sciences and technology; Extrusion; Food industries; Fundamental and applied biological sciences. Psychology; General aspects; glycerol; Handling, storage, packaging, transport; heat; melting; Natural polymers; oils; Oxidized and acetylated corn starch; permeability; Physicochemistry of polymers; plasticizers; Properties; starch; Starch and polysaccharides; temperature; tensile strength; water vapor
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2011.08.048

► Films were made from oxidized and acetylated starch and pullulan blends. ► Extrusion and glycerol content significantly influenced the properties of films. ► The tensile strength of the films were much higher than previous reports. ► Oxidized and acetylated corn starch was an excellent material to make film. Oxidized and acetylated corn starch-based films were prepared by casting with glycerol as a plasticizer. The present study investigated the effects of extrusion prior to film-making and glycerol content on the properties of starch films. The films with extrusion exhibited lower tensile strength, higher elongation at break, higher water vapor permeability and higher oil permeability than those without extrusion. Extrusion reduced heat sealability of the films. With the increase of glycerol content, the films became more flexible with higher elongation at break and lower tensile strength. Water vapor permeability, oil permeability and the range between the onset temperature and the melt peak temperature rose as glycerol content increased. The thermograms indicated that plasticizers and biopolymers were compatible. These results suggested that extrusion did no good to starch films while glycerol content had apparent effect on the mechanical and barrier properties of the films.