PARTICULARITIES IN THE STRUCTURE OF AMYLOPECTIN, AMYLOSE AND SOME OF THEIR DERIVATIVES IN SOLUTION

Because of a well defined supramolecular architecture of the native st arch granules the preparation of molecularly dispersed starch solution s is achieved only after autoclaving at temperatures of 135 to 160 C. A detailed analysis of static light scattering data allowed the determ ination of the molecular parameters of both the amylopectin and amylos e. The results were confirmed by (1) measurements in the iron sodium t artrate complex FeTNa, (2) by extrapolation of the data obtained with degraded starches to no degradation and (3) by sedimentation field-flo w-fractionation sFFF. Above the overlap concentration strong aggregati on due to H-bonding commenced and eventually led to gelation. The proc ess is promoted by the amylose content and could be followed by static and dynamic light scattering. Cationic starches and cationic amyloses display remarkably different behavior. The branched amylopectin expan ded uniformly when the ionic strength was lowered but the correspondin g amylose exhibited an unusual helix-disorder transition.