Abstract: The apparent average molar masses (Mw,app), apparent average radii of gyration (Rg,app), of native sago starch and fractions were determined using asymmetrical flow field-flow fractionation coupled with multi-angle light scattering and refractive index detectors (AF4/MALS/RI). Amylose-type (Fraction A) and amylopectin-type (Fraction B) were chemically separated from native sago starch. Native sago starch and Fractions (A-B) were dissolved in 1M KSCN using a high pressure microwave vessel. The effect of varying cross flow rates at a fixed channel flow rate upon the Mw,app and Rg,app distributions of native sago starch and Fractions (A-B) were investigated. The average Mw,app values of native sago starch, Fraction (A) and Fraction (B) were 60 x 106 g/mol, 1.5 x 106 g/mol and 60 x 106 g/mol, respectively, with average Rg,app values of 142 nm, 75 nm and 127 nm, respectively. The sphere-equivalent hydrodynamic radii (Rh) values for native sago starch and fractions were determined from AF4 experimental parameters.
Abstract: The apparent average molar masses (Mw,app) and apparent average radii of gyration (Rg,app) of native tapioca starch and fractions were determined using asymmetrical flow field flow fractionation (AF4) coupled with multi-angle light scattering and RI detectors (AF4/MALS/RI). AM-type (Fraction A) and AP-type (Fraction B) were chemically separated from native tapioca starch. Native tapioca starch and Fractions (A and B) were dissolved in 1 M KSCN using a high pressure microwave vessel. The effect of varying cross flow rates at a fixed channel flow rate upon the Mw,app and Rg,app distributions of native tapioca starch and Fractions (A and B) were investigated. The average Mw,app values for native tapioca starch, Fraction (A) and Fraction (B) were 59 × 106, 2.1 × 106 and 19 × 106 g/mol, respectively, with average Rg,app values of 165, 73 and 87 nm, respectively. Hydrodynamic radii (Rh) values for native tapioca starch and fractions were determined directly from AF4 experimental parameters.
Abstract: The apparent average molar masses (Mw,app), apparent average radii of gyration (Rg,app), diffusion co-efficients (DT), and hydrodynamic radii (Rh) of normal corn (maize) starch and fractions were determined using asymmetrical flow field-flow fractionation coupled with multi-angle light scattering and refractive index detectors (AF4/MALS/RI). AM-type (Fraction A) and AP-type (Fraction B) were chemically separated from normal corn starch. Normal corn starch and Fractions (A–B) were dissolved in 1 M KSCN using a high pressure microwave vessel. The effect of varying cross flow rates at a fixed channel flow rate upon the Mw,app and Rg,app distributions of normal corn starch and Fractions (A–B) were investigated. The average Mw,app of normal corn starch, Fractions (A) and Fraction (B) were 41 × 106, 1.4 × 106 and 39 × 106 g/mol, respectively, with Rg,app values of 129, 60 and 129 nm, respectively.
Abstract: The molar mass (Mw), radius of gyration (Rg), diffusion co-efficient (D), and hydrodynamic radius (Rh) of amylopectin (waxy maize starch) has been determined using asymmetrical flow field-flow fractionation coupled with multi-angle light scattering and refractive index detectors (AF4/MALS/RI). A high pressure microwave vessel (HPMV) was used to dissolve amylopectin in 1 M KSCN. The effect of varying the flow rates on the Mw and Rg distributions of amylopectin were investigated to determine the optimum flow rates. The average Mw and Rg values of amylopectin determined using the Berry and Debye equations. D and Rh values were determined directly from the AF4 retention times and compared to values obtained by dynamic light scattering.
