Involvement of Polyphenols in the After‐Cooking Darkening of Gamma Irradiated Potatoes

Peeling of potatoes prior to boiling reduces the intensity of gamma irradiation induced after‐cooking darkening of the tuber flesh. Polyphenols in the flesh of cooked whole tubers, pre‐peeled tubers and in the cooking water were determined to examine its role in the darkening. Pre‐peeling results in increased leaching of polyphenols from the flesh into the cooking water thus reducing the amount available for the formation of iron‐phenolics complex responsible for darkening. The results indicate a strong correlation between low polyphenol levels and the reduction in after‐cooking darkening of pre‐peeled potatoes.