Are Dark Green, Leafy Veggies Higher in Vitamin C Content Than Their Lighter-Colored Counterparts?

Research Questions:

• What role does Vitamin C play in the human body?
• What happens if a person has a deficiency of Vitamin C?

Vitamin C is an ascorbic acid. Without it, organisms will not be able to function correctly. It allows essential metabolic reactions to be carried out in the body, which iturnsn , allows the organism to live healthily.

When one thinks of vitamin C, pictures of oranges usually come to mind. That's because vitamin C is abundant in citrus fruits such as oranges, lemons, limes, and grapefruits. But what other foods contain vitamin C? This test will help you find out.

Materials:

• Dark Green, Leafy Veggies- Spinach, Broccoli
• Light Green Veggies- Iceberg Lettuce, Light Green Cabbage or Brussel Sprouts
• Cornstarch
• Iodine
• Water
• Beaker (if you are going to use a burner); Pot (if you are going to use a stove)
• Bunsen Burner (or a stove)
• Blender
• Strainer
• Eyedropper/pipette
• Several test tubes w/ rack
• A white piece of paper
• Pen for taking notes

Experimental Procedure:

Preparing the Vegetables

1. Since vegetables are solid, we need to turn them into liquid first before we can use the indicator solution on it.
2. Simply pulp each of the vegetables in a blender (remember to rinse the blender after each pulp to prevent contamination of results).
3. Strain and keep the juices.

Preparing the Iodine Indicator

1. Mix cornstarch (1 tbsp) and water together to make a paste.
2. Add 250ml of water and boil for about 5 minutes.
3. Using a dropper or a pipette, add 10 drops of the boiled solution to 75ml of water.
4. Add iodine to the mixture until it turns a dark-purple color.

Testing the Vegetables

1. With a dropper, add 5ml of the iodine indicator solution to a standard 15ml test tube. Using a clean dropper (to prevent contamination), add 10 drops of the juice into the test tube.
2. Clean the dropper and do the above for each juice sample.
3. Compare which one turns a darker color. The darker color means there is less Vitamin C present in that particular sample.

Terms/Concepts: Nutrients in Veggies; Nutritional Value; Vitamins & Minerals;  Vitamin C; Ascorbic Acid

References:

• Nutrition Information for Vegetables
• WebMD: The Benefits of Vitamin C
• Vitamin C, the Common Cold, and the Flu, by Linus Pauling (W H Freeman & Co,1976)