With some simple methods we can test whether cooked food or a raw ingredient contains one or more of these nutrients. The tests for presence of carbohydrates, proteins and fats are simpler to do as compared to the tests for other nutrients. For carrying out these tests, we will need solutions of Iodine, Copper sulphate and Caustic soda, few test tubes and a dropper.
Note:- If the required solutions are not available in readymade form, we can prepare them as follows.
- A dilute solution of iodine can be prepared by adding a few drops of tincture iodine(Tincture of iodine or iodine of tincture is an antiseptic, it is also called weak iodine solution. It is usually 2-7% elemental iodine along with potassium iodide or sodium iodide dissolved in mixture of ethanol and water.
It was used from 1908 in pre-0perative skin preparation by Surgeon Antonio Grossich.) to a test tube half filled with water.
- Copper sulphate solution can be prepared by dissolving 2 gm. of copper sulphate in 100 ml. of water.
- 10 gm. of Caustic soda( or sodium hydroxide) dissolved in 100ml of water makes the required solution of caustic soda.