Reactions of Glucose, Fructose, Galactose, Maltose, Sucrose, and Lactose in Select Qualitative Tests

Glucose in Molisch's Test (Observation)

Purple Ring at the junction of two liquids (Glucose)

Glucose in Molisch's Test (Inference)

Glucose is a carbohydrate

Glucose in Benedict's Test (Observation)

Brick red precipitate (color does depend on the amount of sugar, but brick red is the color for MOST sugar) (Glucose)

Glucose in Benedict's Test (Inference)

Glucose is a reducing carbohydrate

Glucose in Barfoed's Test (Observation)

Scanty red precipitate at the bottom of test tube (Glucose)

Glucose in Barfoed's Test (Inference)

Glucose is a reducing monosaccharide.

Glucose in Seliwanoff's Test (Observation)

Cherry red color is not observed. (Glucose)

Glucose in Seliwanoff's Test (Inference)

Glucose is not a keto hexose.

Glucose in Osazone Test (Observation)

Needle shaped crystal (Glucose)

Glucose in Osazone Test (Inference)

Confirmatory test for glucose, as the crystals are needle shaped.

Fructose in Molisch's Test (Observation)

Purple ring at the junction of two liquids. (Fructose)

Fructose in Molisch's Test (Inference)

Fructose is a carbohydrate

Fructose in Benedict's Test (Observation)

Brick red precipitate (color depends on the precipitate) (Fructose)

Fructose in Benedict's Test (Inference)

Fructose is a reducing carbohydrate.

Fructose in Barfoed's Test (Observation)

Scanty red precipitate at the bottom of the test tube. (Fructose)

Fructose in Barfoed's Test (Inference)

Fructose is a reducing monosaccharide

Fructose in Seliwanoff's Test (Observation)

Cherry red color is observed. (Fructose)

Fructose in Seliwanoff's Test (Inference)

Fructose is a keto hexose.

Fructose in Osazone Test (Observation)

Needle shaped crystals (Fructose)

Fructose in Osazone Test (Inference)

Fructose, glucose, mannose form similar crystals.

Galactose in Molisch Test (Observation)

Purple ring at the junction of two liquids. (Galactose)

Galactose in Molisch Test (Inference)

Galactose is a carbohydrate.

Galactose in Benedict's Test (Observation)

Brick red precipitate (color depends on the amount of sugar) (Galactose)

Galactose in Benedict's Test (Inference)

Galactose is a reducing carbohydrate.

Galactose in Barfoed's Test (Observation)

Scanty red precipitate at the bottom of the test tube. (Galactose)

Galactose in Barfoed's Test (Inference)

Galactose is a reducing monosaccharide.

Galactose in Seliwanoff's Test (Observation)

Cherry red color is not observed (Galactose)

Galactose in Seliwanoff's Test (Inference)

Galactose is not a keto hexose.

Galactose in Osazone Test (Observation)

Rhombic plate shaped crystals (Galactose)

Galactose in Osazone Test (Inference)

Confirmatory test for galactose

Maltose in Molisch's Test (Observation)

Purple ring at the junction of two liquids. (Maltose)

Maltose in Molisch's Test (Inference)

Maltose is a carbohydrate.

Maltose in Benedict's Test (Observation)

Brick red precipitate (color depends on the amount of sugar) (Maltose)

Maltose in Benedict's Test (Inference)

Maltose is a reducing carbohydrate.

Maltose in Barfoed's Test (Observation)

No color change (Maltose)

Maltose in Barfoed's Test (Inference)

Maltose is not a monosaccharide.

Maltose in Osazone Test (Observation)

Sunflower shaped crystals

Maltose in Osazone Test (Inference)

Confirmatory test for maltose

Lactose in Molisch's Test (Observation)

Purple ring at the junction of two liquids (Lactose)

Lactose in Molisch's Test (Inference)

Lactose is a carbohydrate.

Lactose in Benedict's Test (Observation)

Brick red precipitate (Color depends on amount of sugar) (Lactose)

Lactose in Benedict's Test (Inference)

Lactose is a reducing carbohydrate.

Lactose in Barfoed's Test (Observation)

No change in color (Lactose)

Lactose in Barfoed's Test (Inference)

It is not a monosaccharide. (Lactose)

Lactose in Osazone Test (Observation)

Powder puff/Hedge hog shaped crystals

Lactose in Osazone Test (Inference)

Confirmatory test for Lactose

Sucrose in Molisch Test (Observation)

Purple ring at the junction of two liquids (Sucrose)

Sucrose in Benedict's Test (Observation)

No color change (Sucrose - Benedict)

Sucrose in Benedict's Test (Inference)

Sucrose is not a reducing carbohydrate.

Sucrose in Barfoed's Test (Observation)

No color change (Sucrose - Barfoed)

Sucrose in Barfoed's Test (Inference)

Sucrose is not a monosaccharide.

Sucrose in Seliwanoff Test (Observation)

Cherry red color

Sucrose in Seliwanoff Test (Inference)

Sucrose is a ketohexose, containing disaccharide.

Sucrose in Hydrolysis (Inversion) Test (Observation)

The hydrolytic products give a positive reaction with Benedict's and Barfoed's reagents.

Sucrose in Hydrolysis (Inversion) Test (Inference)

Confirmatory test for Sucrose

Sucrose in Osazone Test (Observation)

No reaction (Sucrose)

Sucrose in Osazone Test (Inference)

Sucrose does not form any osazone crystals

Maltose in Molisch's Test (Observation)

Purple ring at the junction of two liquids.

Maltose in Molisch's Test (Inference)

Maltose is a carbohydrate.