Anthocyanin is the pigment responsible for the red, pink, purple and blue colours in flowers, fruits and leaves.
Affected tubers show purplish red stripes and flameshaped discolouration of the flesh, the result of anthocyanin formation in the cell sap. Light seems
to play a role in the development of this defect because the production of anthocyanin in tuber flesh has been associated with tuber greening in the field. Proper
hilling reduces this problem.
This defect is rare and usually affects only certain cultivars. The varieties Mainestay and Frontier Russet are susceptible to anthocyanin discolouration.
Purplish-red Pigmentation
