Aspartame sweetener. Polarised light micrograph of crystals of Aspartame, an artificial sweetening food additive. Aspartame is a registered trademark for L-alpha-Aspartyl-L-phenylalanine Methyl Ester, and is also known under the NutraSweet trade name. Its main uses are in canned drinks and foods, and as a consumer-added sweetener in the form of tablets and granules. Magnification x5 at 35mm size.