How to Test for Ascorbic Acid

Ascorbic acid, also known as Vitamin C, is an essential water-soluble nutrient required in humans and animals. It stimulates the production of collagen in the body for the maintenance and development of healthy teeth, bones, skin, joint linings and blood vessels. It is used as a nutritional supplement to treat iron deficiency and prevent scurvy, repair lost tissue, lower the risk of high blood pressure and regulate cholesterol, and to assist in a range of metabolic reactions in plants. It is found mainly in vegetables, juice and fruits, and cannot be stored in the body. Therefore, it must be replenished daily.

Things You'll Need

• Marker
• Tablespoon
• Cornstarch
• Water
• 2 large beakers
• Measuring cup
• Stove
• 2 eyedroppers
• Teaspoon
• 2% iodine solution
• 4 test tubes
• 4 different samples of fruit juices

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Instructions

• 1

  Label the four test tubes -- one for each type of juice -- with the marker. Set them aside.

• 2

  Put 1 tablespoon of cornstarch in the first beaker. Add just enough water to make a paste.

• 3

  Add one cup of water to the paste.

• 4

  Turn on the stove and set the heat to medium. Place the first beaker on the burner and boil for five minutes.

• 5

  Pour 1/3 cup of water into the second beaker.

• 6

  Use an eyedropper to add 10 drops of the boiled starch solution to the water.

• 7

  Add iodine until it turns dark blue or purple.

• 8

  Put 1 teaspoon of your indicator (the dark blue or purple solution) into each of the test tubes.

• 9

  Use the second eyedropper to add 10 drops of each fruit juice into its respective labeled test tube.

• 10

  Observe the color as it changes. The lighter the juice/indicator solution becomes, the more ascorbic acid is present in that juice.