Studies on after-cooking blackening. V. Changes in after-cooking blackening and the chemistry of Majestic and Ulster Beacon tubers during the growing season

Research paper by J. C. Hughes, J. L. Evans

Indexed on: 01 Mar '69Published on: 01 Mar '69Published in: Potato Research


Variations in the concentrations of the main biochemical factors responsible for after-cooking blackening have been followed during the growing season in two varieties with widely differing blackening behaviour (Majestic andUlster Beacon). In both varieties the intensity of blackening decreased and the distribution changed from bud to stem end during the growing season. These changes in blackening were associated with changes in the amount and distribution of citric acid and chlorogenic acid. Highly significant correlation coefficients were found between blackening and chlorogenic acid, blackening and citric acid, and between blackening and the ratio of chlorogenic acid to citric acid. At each harvestMajestic tubers blackened more thanUlster Beacon tubers and always contained larger amounts of chlorogenic acid.