Nanoprecipitation of native pea starches treated in alkaline media at various temperatures employing a dedicated microwave reactor

Starch dispersions/solutions were prepared by heating native pea starch in 1 M NaOH(aq) at various temperatures (50–100°C) using a dedicated microwave reactor. The influence of temperature upon the apparent molecular and hydrodynamic characteristics was investigated employing asymmetrical flow field flow-fractionation coupled with multi-angle light scattering and a RI detector (AF4/MALS/RI). Apparent molar masses, apparent radii of gyration and hydrodynamic radii decreased as a function of increasing processing temperature. Treated starch solutions were precipitated in either ethanol or methanol and the resultant precipitates were dried on either glass or Teflon surfaces. The shapes and sizes of the starch nanoprecipitates (evaluated from SEM images) were influenced by a number of factors including, temperature employed for preparing aqueous starch dispersion/solutions, solvent employed during the precipitation phase, and the nature of drying surfaces.