Sacara struktural, aci ngabentuk clusters of linked linéar polymers, where the alpha-1,4 linked chains form columns of glucose units which branch regularly at the alpha-1,6 links. The relative content of amylose and amylopectin varies between species, and between different cultivars of the same species. Pikeun conto, jagong luhung amilosa ngandung 85% amilosa, sedengkeun aci waxy corn ngandung leuwih ti 99% amilopéktin.