The Science Behind the Color
The violet and indigo hues of these tubers result from naturally occurring pigments called anthocyanins. These compounds are a type of flavonoid, the same group of antioxidants responsible for the deep colors in blueberries, pomegranates, and red wine. Purple varieties are packed with these phytochemicals, meaning they can have two to three times the antioxidant potential of their lighter-fleshed counterparts. While the basic nutrient profile of a potato is generally consistent across varieties, the presence of anthocyanins elevates the purple tuber’s health benefits beyond simple starch and potassium content.
Distinct Varieties of Purple Potatoes
The world of purple potatoes encompasses several distinct varieties, differentiated primarily by their texture, shape, and the saturation of their interior color. One of the most commercially recognized types is the Purple Majesty, known for its uniform, deep purple flesh throughout the entire tuber. This cultivar is classified as a waxy potato, meaning it has a lower starch content, a denser texture, and holds its oval shape well after cooking.
In contrast, the Purple Peruvian is an heirloom type that often presents with an oblong, unruly, or knobby fingerling shape. Its interior is a vibrant purple, but its texture is typically starchier than the Purple Majesty, making it less dense and giving it a fluffier mouthfeel when mashed. The Adirondack Blue is another popular variety, featuring deep blue-purple skin and flesh, sometimes exhibiting a marbled pattern with flecks of white.
The Vitelotte, an old French heirloom, stands out for its elongated, finger-like shape and its dark, almost black-purple skin. Its flesh is characteristically dense and waxy, making it highly valued in European cuisine for preparations like potato salad, where maintaining the integrity of the slice is paramount. Not all purple-skinned potatoes have pigmented flesh; the Purple Viking features striking purple and pink skin but a pure white interior, classifying it as a dual-colored potato.
Preparation and Culinary Characteristics
Purple potatoes possess an earthy, slightly nutty flavor that is more pronounced than the mild taste of white potatoes. Their unique texture influences their culinary application, as most varieties have a moist, firm flesh that resists breaking down during cooking. This makes them suited for dishes like roasted medleys, gratins, and potato salads, where the goal is to maintain distinct, firm pieces.
To best preserve the vibrant color, preparation methods that avoid excessive water contact are recommended, since anthocyanins are water-soluble. Steaming or roasting are the most effective ways to ensure the deep purple hue remains saturated and does not shift to a grayish-blue color, which can happen with prolonged boiling. When making mashed potatoes, the denser, waxier varieties may require more effort to achieve a smooth texture, but they result in a striking, naturally colored side dish.