1. Food Tests
Grade8

2. Test for starch Collect the food sample (liquid) in a test tube.
Add few drops of iodine solution.(yellowish brown)
If the colour changes from yellowish brown to blue black then this substance contains STARCH

3. Test for fat Collect the food sample (liquid) in a test tube.
Add ethanol and shake well.
Add water.
If a cloudy mixture appears then the food sample contains FAT.

4. Test for protein Collect the food sample (liquid) in a test tube.
Add 5 drops of copper sulphate.
Add 5 drops of sodium hydroxide.
If the colour changes from blue to purple then the food sample contains PROTIEN.

5. Test for sugar (glucose)
Collect the food sample (liquid) in a test tube.
Add few drops of Benedict’s solution.
Place the test tube in a boiling water bath.
If the colour changes from blue to green to orange to a red deposit, then the sample contains SUGAR (GLUCOSE)
The colour change depends on the concentration of sugar in the sample.

6. Food tests These are some of the most common food tests:
Turns cloudy white
Emulsion test
Fats
Turns purple
Biuret test
Proteins
Turns red
Benedicts solution
Sugars
Turns blue-black
Iodine
Starch
Result
Test
Substance tested