Improved material properties of solution-cast starch films: Effect of varying amylopectin structure and amylose content of starch from genetically modified potatoes. (5th October 2015)

• Record Type: Journal Article
• Authors: Menzel, Carolin; Andersson, Mariette; Andersson, Roger; Vázquez-Gutiérrez, José L.; Daniel, Geoffrey; Langton, Maud; Gällstedt, Mikael; Koch, Kristine
• Is Part Of: Carbohydrate polymers. Volume 130(2015)
• Page Start: 388
• Page End: 397
• Publication Date: 2015-10-05
• Subjects: High-amylose potato starch -- Film forming -- Molecular structure -- Chain-length -- Amylopectin -- Microscopy; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2015.05.024
• Languages: English
• ISSNs: 0144-8617

Abstract

Highlights: Targeted gene suppression in potato resulted in starches with increased amylose content. High-amylose starch exhibited changed granular and molecular structures with longer amylopectin chains. Starch with high amylose and long-chain amylopectin improved physical properties of films. Starch films were stiffer and stronger probably due to interconnected starch network. Results suggest great potential of these starches for renewable barrier coatings. Abstract: High-amylose potato starches were produced through genetic modification resulting in changed granule morphology and composition, with higher amylose content and increased chain length of amylopectin. The increased amylose content and structural changes in amylopectin enhanced film-forming behavior and improved barrier and tensile properties in starch films. The molecular structure in these starches was related to film-forming properties. Solution-cast films of high-amylose starch revealed a homogeneous structure with increasing surface roughness at higher amylose content, possibly due to amylose aggregation. Films exhibited significantly higher stress and strain at break compared with films of wild-type starch, which could be attributable to the longer chains of amylopectin being involved in the interconnected network and more interaction between chains, as shown using transmission electron microscopy. The oxygen permeability of high-amylose starch films was significantly decreased compared with wild-type starch. The nature of the modified starches makes them an interesting candidate for replacement of non-renewable oxygen and grease barrier polymers used today.