Potato Research Centre
By Gilles Boiteau
Starch Granule Difference in Heritage Potato Cultivars
Heritage potato cultivars—with their great diversity of tuber shape, color and taste—continue to serve as a valuable genetic resource for potato genetic improvement as well as for gardening. Potato starch granules were already known to be unique compared to other crop starches but recent work at Agriculture and Agri-Food Canada’s Potato Research Centre in Fredericton, N.B., revealed that the shape and size of starch granules vary among different heritage potato cultivars.
Researcher Xiu-Qing Li analyzed the starch granules in fresh potatoes of 14 heritage cultivars including Angelina Mahoney’s Blue, Bliss Triumph, Cherokee, Columbia Russet, Congo, Crotte d’Ours, Gold Coin, Green Mountain, Houma, Irish Cobbler, La Veine Rose/Belle Rose, Russet Burbank, Siberian and Up To Date. Crotte d’Ours was found to have starch granules with irregular and sand-like shape, while those in Bliss Triumph were oblong and relatively regular in shape. Russet Burbank tubers showed the largest starch granules on average while Congo, a blue cultivar, had the smallest. The observation is interesting considering the importance of starch granule morphology for starch applications in the industry.