Purple potatoes

The purple potatoes are a kind of sweet potatos (Ipomoea batatas) of the family Convolvulaceae. They are not very common, native to South America, where they are very known and used, purple potatoes begin to expand everywhere. The characteristic purple color is given by anthocyanins, molecules with important health properties. Anthocyanins, found in both the peel and in the flesh, help indeed fight the aging process, they are a protection for the cardiovascular system from stroke and heart attack and have an anti-cancer action. The purple potatoes contain also good amounts of potassium, important for the control of blood pressure. A study, conducted in 2012 and published on the Journal of Agricultural and Food Chemistry, shows that purple potatoes help to lower the blood pressure. As for the preparation, as reported in the book "The Smartfood diet" written by Eliana Liotta, the boiling, as well as the cooking in the microwave and steaming, increase the availability of anthocyanins: for this reason a good way to prepare the purple potatoes is to boil them with peel and eat them once cooled.