Nutrition

Maize provides 70 percent or more of food energy calories in parts of Mexico, Central America, Africa, and Romania. In these regions, adult workers consume some 400 grams of maize daily, a diet marginally sufficient in calories, protein, vitamins, and minerals, depending on how the maize is processed and the supplementary foods with which it is combined. Maize is a better source of energy than other cereal grains because of its higher fat content. Ground maize meal has 3,578 calories per kg, mostly carbohydrate, with about 4.5 percent “good” fat (fat-rich varieties are double this figure), and is high in essential linoleic and oleic fatty acids. It contains about 10 percent protein, roughly half of which is zein that is low in the amino acids lysine and tryptophan. The protein quality is enhanced in traditional Latin American maize diets by alkali processing and consumption with legumes that are high in lysine. Potatoes, if eaten in sufficient quantity, also yield a considerable amount of lysine and consequently often complement maize in highland South America and parts of Europe. Of course, incorporating animal proteins improves the nutritional quality of any diet with grain or tubers as the staple.

Maize is also naturally low in calcium and niacin, but calcium, niacin, and tryptophan content are all enhanced by traditional alkali processing (in which the kernels are cooked and soaked in a calcium hydroxide - lime or ash - solution), which adds calcium and increases the available tryptophan and niacin in the kernels or dough. White maize, usually the favored type for human food, is also low in vitamin A, although this nutrient is higher in properly stored yellow maize. Moreover, in its traditional heartland, maize is combined with chilli peppers, other vegetables, and various kinds of tomatoes and spices, all of which enhance the amount of vitamin A delivered to the consumer, along with other vitamins and minerals. In Africa and Asia, additional vitamins and minerals are added to maize diets when wild or cultivated greens, other vegetables, peanuts, and small bits of animal protein are combined in a sauce. Potash, burned from salt grasses, also enhances the otherwise poor mineral content of the diet (FAO 1953).