Ethylene diamine tetraacetic acid
Ethylene diamine tetraacetic acid (EDTA) is an organic compound used as a preservative. Its antimicrobial effect is due to its ability to bind to trace minerals such as calcium and magnesium, rendering them unavailable for use by growing microbes. EDTA is used in its acid form and also as the sodium substituted bases disodium ethylene diamine tetraacetate (disodium EDTA) and tetrasodium ethylene diamine tetraacetate (tetrasodium EDTA). These different varieties have essentially the same properties as preservatives.
EDTA is sometimes referred to as an 'amino acid'. While true chemically (it has both an amino and a carboxyl group), it is not an amino acid in a nutritional sense and is not one of the amino acids used to make proteins nor does it have a similar shape.