Benedict's test for sugars. Benedict's reagent is a chemical reagent that is used as a test for the presence of reducing sugars and aldehydes, and alpha-hydroxy-ketones (monosaccharides, lactose, maltose, fructose, etc). The reagent consists of sodium carbonate, sodium citrate and copper sulfate. Here the reagent was added to two test tubes containing 20 g/L solutions of sucrose (table sugar) and glucose. After the tubes were placed in a hot water bath for few minutes, the color of the non-reducing sugar (sucrose) solution did not change, while the color of the reducing sugar (glucose) solution changed to brick-red/brown due to formation of copper oxide precipitate.