Test the presence of adulterant metanil yellow in dal
Metanil yellow is a synthetic dye which is not permitted to use as food colour. However it is used extensively in India to give yellow colour to Dal (pulses) and turmeric. Metanil yellow is toxic by nature and it has adverse effects on liver, intestine and brain.
To test the presence of metanil yellow in dal, take the following steps:
- Take approximately 5 gms of dal in a test tube and add 5 ml of water.
- Shake the test tube well.
- Add few drops of concentrated hydrochloric acid to the test tube. (This activity should be done in the presence of your school teacher).
- The appearance of a pink colour in the solution confirms the presence of metanil yellow in dal
(MCQs asked in CBSE examination)
Q1: Metanil yellow changes the colour of solution of dal to
(a) green
(b) pink
(c) blue
(d) dark red