Vitamin C, is a vital component that should be a part of the diet to keep ourselves healthy. A person with deficiency in this vitamin will have a condition called scurvy. This is because, vitamin C plays an important role in the synthesis of collagen that plays an important role in the connective tissues. Citrus fruits like oranges and lemons are sources rich in vitamin C.
The Royal society of Chemistry in its publication of global experiments,2013, has given a detailed protocol to measure the amount of Vitamin C present in our food.
Split the class room into groups and provide each team with different fruits and vegetables. Follow the procedure given below to estimate the amount of Vitamin C present in the food. Compare the results.
- Prepare your starch solution by putting a teaspoon of cornflour into a cup and ¾ fill it with hot water. Stir the suspension for a minute each time it is used.
- Use the table below to record how much vitamin C is in the tablet (A).
- Make the calibrated solution by dissolving a vitamin C tablet in 1 litre of water. Note this volume in the table (B).
- Place 10 ml of your calibrated solution in a clean plastic cup. Note this volume in the table (D).
- Add water until the cup is about half full. Add 5 ml of starch solution to your cup and stir.
- Carefully add tincture of iodine drop by drop to the cup and count the number of drops. Stir the solution gently after each drop.
- Stop adding drops when the solution turns a deep purple/black colour. Note down the total number of drops required (F).
- Calculate the mass of vitamin C that reacts with one drop of iodine(G). Calculate the average mass of vitamin C that reacts with one drop of iodine.
Similarly, the amount of vitamin C can be estimated in different kind of foods like
- Cooked v/s raw food
- Old v/s fresh food
- Boiled food v/s fried food
- Food left over night
The food that contains the most amount of Vitamin C is _________________________.
Term: Term 1