A common artificial sweetener found in Equal®, NutraSweet®, and many diet sodas is aspartame (C14H18N2O5). Would a sample of pure aspartame test positive or negative for reducing sugars? (The pure sample does not contain other ingredients, such as dextrose, maltodextrin, or calcium silicate.)

Answer: Negative

Explanation:

Any kind of sugar that develops ketone or aldehyde groups in the presence of alkaline solution of the reducing sugar. The kind of reducing sugars includes fructose, lactose, glucose, and maltose but sucrose is not a reducing in nature. Also, a reducing sugar reduces certain kind of chemicals in the oxidation reaction.

The aspartame is an artificial sweetener. It consists of amino acids L-phenylalanine and L-aspartic acid. The sugar is absent in this composition. Since, there is no reducing group available in this dipeptide molecule thus aspartame gives negative result for the reducing sugar test. Aspartame does not form ketone and aldehyde groups in presence of alkaline solution.

Thus the sample with pure aspartame test will give negative result for reducing sugars.