What is the difference between starch test and protein test?
The starch test and protein test are simple laboratory tests used to identify different nutrients in food. The starch test detects the presence of starch using iodine solution, while the protein test (Biuret test) detects proteins using copper sulphate and sodium hydroxide solutions.
| Starch Test | Protein Test (Biuret Test) |
|---|---|
| Used to detect the presence of starch in food. | Used to detect the presence of proteins in food. |
| Uses iodine solution as the testing reagent. | Uses copper sulphate solution and sodium hydroxide solution as testing reagents. |
| A blue-black colour indicates the presence of starch. | A violet or purple colour indicates the presence of proteins. |
| Commonly performed on foods such as potatoes, rice, bread, and cereals. | Commonly performed on foods such as milk, eggs, pulses, beans, and paneer. |
Both tests are commonly performed in school science laboratories to identify nutrients present in different food samples.