The plantain (also called plátano), a very large, firm variety of banana, is also referred to as a "cooking banana" and is extremely popular in Latin American countries as well as parts of Africa, Asia and India. Its skin ranges in color from green to yellow to brownish black; its flesh, from cream to salmon-colored. Whereas the sweet banana is eaten ripe, the plantain is typically cooked when green. It has a mild, almost squashlike flavor and is used much as a potato would be, in a vegetable side dish. If it's allowed to ripen, the plantain has a slightly sweet flavor and a soft, spongy texture when cooked. Bananas are high in carbohydrates and low in protein and fats; they're also rich in potassium and vitamin C.
From The Food Lover's Companion, Fourth edition by Sharon Tyler Herbst and Ron Herbst. Copyright © 2007, 2001, 1995, 1990 by Barron's Educational Series, Inc.