PROGRESSIVE DISSOCIATION OF PECTIN

The structural organization of alkaline soluble peach pectin was inves tigated over size ranges extending from micrometers to tenths of nanom eters. Analysis was by electron microscopy and high-performance anion- exchange chromatography (HPAEC). Superimposed and individual circular microgels in the micrometer size range were isolated from mesocarp tis sue of cell walls and visualized by rotary shadowing. Dilute NaCl and 50% aqueous glycerol disaggregated these microgels into rods, segmente d rods, and kinked rods, which collectively comprised the internal gel network of the microgels. Image analysis of the shadowed specimens be fore and after disaggregation followed by curve fitting of the smoothe d distributions revealed a multimodal distribution of lengths. HPAEC r evealed that the multimodal aggregates were stable for the most part t o further dissociation by increasing ionic strength.