Wheat starch carbamate: Production, molecular characterization, and film forming properties. (15th September 2017)

• Record Type: Journal Article
• Authors: Menzel, Carolin; Seisenbaeva, Gulaim; Agback, Peter; Gällstedt, Mikael; Boldizar, Antal; Koch, Kristine
• Is Part Of: Carbohydrate polymers. Volume 172(2017)
• Page Start: 365
• Page End: 373
• Publication Date: 2017-09-15
• Subjects: Wheat starch -- Film formation -- Molecular structure -- Urea -- Microscopy -- Carbamate; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2017.05.053
• Languages: English
• ISSNs: 0144-8617

Abstract

Highlights: Thirteen wheat starch carbamates with varying degrees of substitution were produced. Successful up-scaling of starch carbamate production. Films of starch carbamates could be produced without catalyst (sulfuric acid). Apparent cross-linked starch carbamates showed best film-forming properties. The described method requires no use of toxic organic solvent or hazardous substance. Abstract: Wheat starch carbamates of different degrees of substitution were produced in laboratory experiments and for the first time their film forming performance were investigated. The carbamation reaction between urea and starch was investigated using a factorial design. Long reaction time, 2 h, and high urea content, 10 and 25%, resulted in a high degree of substitution, 0.07 and 0.15, respectively. These starch carbamates were assumed to be cross-linked and showed best film forming properties resulting in continuous and firm films. Furthermore, a high degree of carbamate substitution favored a decrease in glass transition temperature (Tg ) in cast films. The addition of acid as a catalyst for carbamation of starch produced inconsistent results and mainly lead to degradation of starch molecules that caused brittle films. FTIR and 13 C NMR analyses confirmed the covalent bonding between urea and starch in starch carbamates. In a final step, production of starch carbamates was successfully scaled up. A potential industrial use of these starches is as oxygen barrier in multilayer food packaging.