Size separations of starch of different botanical origin studied by asymmetrical-flow field-flow fractionation and multiangle light scattering.

Summary, in English

Asymmetrical-flow field-flow fractionation combined with multiangle light scattering and refractive index detection has been revealed to be a powerful tool for starch characterization. It is based on size separation according to the hydrodynamic diameter of the starch components. Starch from a wide range of different botanical sources were studied, including normal starch and high-amylose and high-amylopectin starch. The starch was dissolved by heat treatment at elevated pressure in a laboratory autoclave. This gave clear solutions with no granular residues. Amylose retrogradation was prevented by using freshly dissolved samples. Programmed cross flow starting at 1.0 mL min(-1) and decreasing exponentially with a half-life of 4 min was utilised. The starches showed two size populations representing mainly amylose and mainly amylopectin with an overlapping region where amylose and amylopectin were possibly co-eluted. Most of the first population had molar masses below 10(6) g mol(-1), and most of the second size population had molar masses above 10(7) g mol(-1). Large differences were found in the relative amounts of the two populations, the molar mass, and hydrodynamic diameters, depending on the plant source and its varieties.

• Author: Karl-Gustav Wahlund; Mats Leeman; Stalin Santacruz
• Department/s: Centre for Analysis and Synthesis; Department of Chemistry
• Publishing year: 2011
• Language: English
• Pages: 1455-1465
• Publication/Series: Analytical and Bioanalytical Chemistry
• Volume: 399
• Links: http://dx.doi.org/10.1007/s00216-010-4438-5
• Document type: Journal article
• Publisher: Springer
• Topic: Analytical Chemistry
• Status: Published
• ISBN/ISSN/Other: ISSN: 1618-2642