What is a Positive test for reducing sugar results?

Benedict's Test

- Benedict's qualitative reagent is a deep blue solution.

- Positive result: When reducing sugars oxidizes and reduces the cupric ions in Benedict's reagent to cuprous ions, the color changes from blue to green to yellow to orange, or even red-orange, indicating the presence of reducing sugar.

Fehling's Test

- Fehling's qualitative reagent consists of two solutions, Fehling's A and Fehling's B, which are mixed in equal volumes before performing the test.

- Positive result: When reducing sugar reduces cupric ions in Fehling's reagent to cuprous oxide, a red-orange precipitate forms, indicating the presence of reducing sugars.

Barfoed Test

- Barfoed's reagent is a solution containing copper acetate and acetic acid.

- Positive result: A red precipitate of cuprous oxide is formed, indicating the presence of reducing sugar.

Nylander's Test

- Nylander's reagent consists of bismuth subnitrate, sodium potassium tartrate, and sodium hydroxide in solution.

- Positive result: A black or gray precipitate forms when reducing sugars react with bismuth subnitrate to produce elemental bismuth.