Determination of molar mass distribution of tapioca starch using asymmetrical flow field flow fractionation

The apparent average molar masses (M_w,app) and apparent average radii of gyration (R_g,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 M_w,app and R_g,app distributions of native tapioca starch and Fractions (A and B) were investigated. The average M_w,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 R_g,app values of 165, 73 and 87 nm, respectively. Hydrodynamic radii (R_h) values for native tapioca starch and fractions were determined directly from AF4 experimental parameters.