Cation starches (H-, Na-, Ca-starch) which were stored during 18 years were studied for changes in depolymerization, release of inorganie phosphate, paste consistency, orientation of their crystalline structure and morphology of granules. The results obtained indicate that ageing is accompanied by a decomposition of glycosidic linkages, ester linkages of phosphoric acid and changes of the rheological properties of starch paste. The biggest changes were observed in the case of hydrogen starch, whereas sodium and potassium starches underwent comparatively small changes.
The physico-chemical properties of starch in some uncultivated potato varieties were determined. No significant differences were found between the examined samples and cultivated potato starches except for a lower content of amylose in same samples and certain variations in the morphology of starch grains.