The meso-American practice of cooking corn with lime and serving it with beans, like the Asian practice of fermenting soy and serving it with rice, turn out to render these plant species much more nutritious than they otherwise would be.
unless corn is cooked with an alkali like lime its niacin is unavailable, leading to the nutritional deficiency called pellagra.
Corn and beans each lack an essential amino acid (lysine and methionine, respectively); eat them together and the proper balance is restored.
Similarly, a dish that combines fermented soy with rice is nutritionally balanced.
