Barfoed's Test is used to identify a Monosaccharide.
1 mL of Barfoed's Reagent, copper (II) acetate in acetic acid, was added to 0.5 mL of each sample.
Samples were then heated for 2 min in boiling water, followed by cooling in an ice water bath.
Monosaccharides will be oxidized in the reaction, while the copper (II) acetate will be reduced to copper (I) oxide, producing a red precipitate that will settle to be bottom of the test tube.
To better identify the samples that reacted, 1 mL of phosphomolybdic colour reagent was added to each sample after heating. The copper (I) oxide will react with the phosphomolybdic to produce a dark blue colour when the phosphomolybdic is reduced.

Take note that if polysaccharides and disaccharides are heated too long, the glycosidic bond may be broken, resulting in the production of monosaccharides. This may result in a false positive result of Barfoed's test.

Blue colour change = Monosaccharide

Negative Control = Distilled Water
Positive Control = 1 % (w/v) Glucose
Positive Control = 1 % (w/v) Lactose
Positive Control = 1 % (w/v) Starch
Unknowns Tested = 12

Alphabetical list of Samples:
0% Skim Milk, 2% Milk, 2% Lactose-free Milk, 2%+ Milk (+ Protein), 5% Light Cream, 10% Table Cream, 35% Whipping Cream, Almond Milk, Cashew Milk, Coconut Milk , Oat Milk, Soy Milk