M5: CARBOHYDRATES (Part 2)

Moore’s Test

[+] Yellow turns dark brown solution with caramel odor; Presence of Reducing sugars (Aldoses & Ketoses)

1% NaOH

Strong base

1% Ba(OH)2

Weak base

Tollen’s Test (Silver Mirror Test)

[+] Silver mirror on the innerside of the test tube; Presence of Reducing sugars (Aldoses)

Fehling’s Test

[+] Blue solution w/ Brick red precipitate; Presence of Reducing sugars (Aldoses & Ketoses)

Nylander’s Test

[+] Black Precipitate; Presence of reducing sugar

Benedict’s Test

[+] Brick red precipitate; Presence of Reducing sugar

No reducing sugar (Benedict’s Test)

Blue

Traceable (Benedict’s Test)

Green

Low (Benedict’s Test)

Yellow

Moderate (Benedict’s Test)

Orange red

High (Benedict’s Test)

Brick red

Iodine (Iodine-potassium iodide)

Staining distinguishes starch from monosaccharides or disaccharides, and other polysaccharides. The basis for this test is that starch is a coiled polymer of glucose, iodine interacts with these coiled molecules and becomes [+] bluish black.

Starch (Iodine Test)

Bluish black

Amylodextrin (Iodine Test)

Blue- purple

Erythrodextrin (Iodine Test)

Red

Achroodextrin (Iodine Test)

Colorless

Glycogen

[+] Red brown solution

Glucose

[+] Light yellow/ Colorless solution