Amino acids are used as food additives because it combines to make proteins. Amino acids are used as additive in fortification of rice with L-threonine and L-lysine, supplementation of bread with L-lysine and fortification of soya and peanut protein with methionine. When an individual consumes food that contains protein, their digestive system breaks the protein down into amino acids. The body then associations the amino acids in different ways to carry out body functions.