Developed in 1890 and promoted as a health food at the 1904 St. Louis World's Fair, peanut butter is a blend of ground shelled peanuts, vegetable oil (often hydrogenated) and usually a small amount of salt. Some contain sugar and additives to improve creaminess and prevent the oil from separating. It takes around 850 peanuts to produce an 18-ounce jar of peanut butter. Reduced-fat peanut butter only contains about 60 percent of the peanuts of the regular version, replacing them with maltodextrin (a type of cornstarch) and soy protein. Both versions contain the same number of calories per serving (about 190), but reduced-fat peanut butter has 12 grams of fat, compared to 16 grams for the regular. Natural peanut butter uses only peanuts and oil, usually peanut oil. Peanut butter is sold in two forms smooth or chunky, which contains bits of peanut. It can be easily made at home in a blender or food processor. Natural peanut butter must be refrigerated after opening and can be stored in this manner up to six months. Most other commercial peanut butters can be stored at room temperature for up to six months. Peanut butter is high in fat and contains fair amounts of iron, niacin and protein.
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.