aspartame /aspär″tām, as″pərtām/ , a white, almost odorless crystalline powder that is used as an artificial sweetener. It is formed by binding the amino acids of phenylalanine and aspartic acid. Approximately 180 times as sweet as the same amount of sucrose, it is used mostly to sweeten cold or uncooked foods. Unprotected aspartame tends to lose its sweetness in the presence of heat, moisture, and alkaline media. Use of this nonnutritive sweetener should be avoided by patients with phenylketonuria (PKU) because the substance hydrolyzes to form aspartate and phenylalanine.
