We must have vitamin C to live, but our bodies do not produce it. Therefore, we must get it from what we eat. The problem is this: even if we eat a food that we know contains vitamin C, our preparation to eat it (boiling the food, for example) may cause vitamin C to leave a food.
Vitamin C (its chemical name is ascorbic acid) is one of the most important vitamins our bodies need, not only to stay alive, but also to keep in optimum health. Vitamin C is necessary in the formation of collagen, which is used to maintain skin, bones, and supportive tissue. Vitamin C strengthens the immune system and aids in healing wounds.
The process of cooking may cause vitamin C to be lost in foods, so that when we eat them, we are not getting this much-needed nutrient.
Is it healthier to eat a carrot raw or boiled regarding vitamin C? In this project, we will boil carrots in water and test the water for vitamin C content before and after the carrots have been boiled in it. If no vitamin C is present in the water before boiling, but is present afterwards, then the cooking process has removed vitamin C from the carrots, thereby making them less nutritious to eat.
Hypothesize that when carrots are boiled in water, vitamin C will be lost in the carrots. This will be evidenced by an increase in the vitamin C content of the water in which the carrots were boiled.
- One carrot
- Two large test tubes
- Teaspoon measure
- Distilled water
- Corn starch
- Vitamin C tablet (250 milligram)
- Measuring cup
- Cooking pot
- Use of a stove burner
- Vegetable peeler
- Possible adult supervision needed
When working around a hot stove, use caution. Also, do not put iodine in your mouth or bring it in contact with anything edible, because iodine is poisonous.
Pour one cup of distilled water in a cooking pot. Add ½ teaspoon of cornstarch. Heat on a stove burner. Stir until dissolved, and then set aside to cool.
Pour one teaspoon of this solution into one cup of distilled water. Add four drops of iodine and stir. The solution will turn dark blue. This is our vitamin C test solution. When vitamin C is added to this solution, the dark blue coloring will vanish.
Prove this solution will work in detecting vitamin C by dropping a 250 milligram tablet of vitamin C into the test solution. As the tablet dissolves, the water will instantly become clear.
Now that you have proven the test solution will detect the presence of vitamin C, make another batch of the test solution by pouring one teaspoon of the cornstarch solution into one cup of distilled water and adding four drops of iodine.
Place two large test tubes in holders side-by-side. Pour distilled water into one test tube until it is ¾ full. A funnel is helpful. Using an eye dropper, add drops of the vitamin C test solution until you begin to see the water turning slightly blue. It may take 50 or 60 drops before a color change can be detected. Write down the number of drops added when you first see the blue color.
Cut a carrot into small pieces or use a peeler to slice it into long, thin slivers. Place the pieces in a cooking pot with one cup of distilled water. Bring to a boil for several minutes, and then remove the pot from the heat and let it cool.
Position the funnel in the mouth of the second test tube and pour in the water from the carrot pot until the test tube is ¾ full.
With an eyedropper, add drops of the vitamin C test solution to the carrot water. If vitamin C is present in the water, the water will not show any signs of turning blue when the same number of drops are added that were added to the water before carrots were cooked in it. Can you fill the rest of the test tube and still not see any shades of blue? If so, a significant amount of vitamin C is present. The carrot lost some of its nutritional value to the water.
Write down the results of your experiment. Document all observations and data collected.
Come to a conclusion as to whether or not your hypothesis was correct.
- Can any more vitamin C be extracted from the carrot pieces? Place the carrot pieces in a fresh cup of distilled water, reheat, and then retest for the presence of vitamin C in the water. If more vitamin C came out, then some vitamin C was still in the carrot, even though some was lost initially to cooking.
- Does steaming vegetables retain more vitamin C in the vegetable than boiling them? If so, people who like their vegetables cooked, but who are concerned about maintaining a high level of vitamin C, could steam their vegetables rather than boil them.
- Can you make a tasty drink from the boiled carrot water? If so, it would be nutritious, because the boiled water contains vitamin C from the carrots.