Stop the Scurvy – Vitamin C Test

What You Do:

  1. Choose several foods to test: tomato juice, orange juice, lemon juice, mango, kiwi, etc. You may also choose a food product that says it has vitamin C added. (If it is a solid, grind it up and mix with water to make a solution.)
  2. Make indophenol solution by combining a small amount of indophenol (less than 1/8 teaspoon) with 1 cup of water. Stir until it is well mixed.
  3. Use a pipet to put 15 drops of indophenol solution into a test tube.
  4. Add one of the juices to the indophenol drop by drop. Record how many drops it takes to turn the blue indophenol colorless.
  5. Repeat with the other juices and compare the number of drops of each that you added.

 

Featured Kit
Chemistry of Food KitStudy the chemical components of everyday foods with qualitative tests for glucose, starch, protein, and vitamin C. Kit includes five experiments plus ideas for students to try on their own. Contains  test tubes, a beaker, biuret reagent, benedict’s solution, indophenol, iodine, and more. You provide items like crackers and juice. Ages 13 & up.

 

What Happened:

Vitamin C is a vital nutrient for humans that aids our immune system and helps prevent disease. Many animals can make their own vitamin C, but humans must get it from their diet, which is why the vitamin C content of the food we eat is important.

Scurvy is caused by a lack of vitamin C. At one time it was common among sailors and pirates because they had no access to fruits and vegetables at sea. Before its cause was known, scurvy claimed the lives of many long-distance ship passengers and crew.

Indophenol is an indicator that turns colorless in the presence of vitamin C. The fewer drops of juice you need for the color change, the higher the vitamin C content in the juice. Which fruits had the most vitamin C? Do you think different preserving methods (canning, drying, freezing) has an effect on vitamin C? Do some more tests to find out!