Quality Protein Maize (QPM) is a family of maize varieties. QPM grain contains nearly twice as much lysine and tryptophan, amino acids that are essential for humans and monogastric animals but are limiting amino acids in grains. QPM is a product of conventional plant breeding (i.e., it is not genetically modified) and an example of biofortification. QPM was developed by Surinder Vasal and Evangelina Villegas at the International Maize and Wheat Improvement Center (CIMMYT) in the late 1990s. For their achievement, they won the 2000 World Food Prize. Need for quality protein maize In Central and South America, Africa, and Asia, several hundred million people rely on maize as their principal daily food, for weaning babies, and for feeding livestock. Unfortunately maize (corn) has two significant flaws; it lacks the full range of amino acids, namely lysine and tryptophan, needed to produce proteins, and has its niacin (vitamin B3) bound in an indigestible complex. The Mayans and Aztecs used to boil maize in alkaline limewater, nixtamalization, which broke down the complex so that the Niacin became available. However, in the main this practice did not transfer to the Old World or settlers in the "New World" which resulted in epidemics of Pellagra from the 16th century onwards. In addition diets high in corn produce a condition known as wet-malnutrition a person is receiving sufficient calories, but her or his body malfunctions due to a lack of protein. A chronic lack of protein in the diet leads to kwashiorkor. Thus, conventional maize is a poor-quality food staple; unless consumed as part of a varied diet which is beyond the means of most people in the developing world. QPM produces 70–100% more of lysine and tryptophan than the most modern varieties of tropical maize. These two amino acids allow the body to manufacture complete proteins, thereby eliminating wet-malnutrition. In addition tryptophan can be converted in the body to Niacin, which theoretically reduces the incidence of Pellagra. Development Modified maize with higher protein content dated back to the 1920s, and the "opaque-2" variety had been developed in 1963. While its lysine and tryptophan levels were better than those of conventional maize, opaque-2 had lower yields and a soft, chalky kernel, which made it more susceptible to ear rot and insect damage. Moreover, the taste and kernel appearance dissatisfied consumers, who ultimately rejected the enhanced-protein varieties in the market. Vasal-Villegas team Surinder Vasal and