These seeded pods of various legumes are among the oldest foods known to humanity, dating back at least 4,000 years. They come in two broad categoriesfresh and dried. Some beans, such as the black-eyed pea, lima bean and cranberry bean, can be found in both fresh and dried forms. Fresh beans are commercially available in their fresh form and are generally sold in their pods. The three most commonly available fresh-bean varieties are the green bean (eaten with its shell or pod), and the lima bean and fava (or broad) bean, both of which are eaten shelled. Store fresh beans in a tightly covered container in the refrigerator for up to five days; after that, both color and flavor begin to diminish. If cooked properly, fresh beans contain a fair amount of vitamins A and C; lima beans are also a good source of protein. Dried beans are available prepackaged or in bulk. Some of the more popular dried beans are the black bean, chickpea, kidney bean, pink bean and pinto bean. Dried beans must usually be soaked in water for several hours or overnight to rehydrate them before cooking. Beans labeled "quick-cooking" have been presoaked and redried before packaging; they require no presoaking and take considerably less time to prepare. The texture of these "quick" beans, however, is not as firm to the bite as regular dried beans. Store dried beans in an airtight container for up to a year. Gas and beans: The flatulence caused by dried beans is created by oligosaccharides, complex sugars thatbecause they're indigestible by normal stomach enzymesproceed into the lower intestine where they're eaten (and fermented) by friendly bacteria, the result of which is gas. Dried beans are rich in protein, calcium, phosphorus and iron. Their high protein content, along with the fact that they're easily grown and stored, make them a staple throughout many parts of the world where animal protein is scarce or expensive.
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.