[Changes in vitamin C content of Bintje potatoes during storage and usual culinary preparations].

In various regions of France (particularly in the North-East) potatoes have remained an important source of vitamin C. We measured by a specific method [7], the loss of ascorbic acid in the Bintje species of potatoes (grown in Pas-de-Calais) due to storage and different cooking procedures. Storage for 3 months in the dark at +12 degrees C decreases the ascorbic acid level by about 50%, storage for 6-8 months by about 66%. Cooking of peeled potatoes (in water, vapor or as French fries) causes an additional loss of vitamin C of roughly 40-45% whereas unpeeled potatoes loose only about 7% by cooking. When cooked potatoes are kept warm, on a hot plate, for an hour the loss of ascorbic acid amounts up to 70%. Thus three major factors determine the spontaneous destruction of ascorbic acid in potatoes, i.e. the length and conditions of storage (aging), the way of cooking and warming up. Potatoes, even when consumed in considerable quantities, can only supply part of the French recommended Daily Allowance [8] particularly from January through June.