Common food adulterants and their testing methods

1. Mixing yellow coloured lead chromate powder to turmeric powder.
2. Mixing toxic kesari dal to arhar dal.
3. Mixing powder dung to dhania powder.
4. Mixing dried papya seeds to black pepper.
5. Mixing sugar/jaggery to honey.
6. Adding starch,and water to milk.
7. Mixing brick powder/saw dust to red chiili powder.

TEST OF ADUTERATION

Test for vanaspati in butter:
Heat about 2 g of butter in a test-tube and add1-2 ml of conc. HCl and a pinch of sugar. Shake the test-tube, and keep it undisturbed for 5 minutes. Appearance of deep red layer confirms the presence of vanaspati in butter.

Test for argemone oil in edible oil:
Heat 4-5 ml of oil with 2-3 ml of conc.HNO₃ in a test tube, and observe the colour of the lower layer in the test tube. A red lower layer confirms the presence of argemone oil in the given sample of the edible oil.

Test for metanil yellow in dal:
Take 4-5 g of dal,5 ml of water,and a few drops of conc. HCl in a test tube. If a pink colour is obtained, presence of metanil yellow in the given sample of dal is confirmed.

Test for presence of water in milk:
Take a drop of milk on clean glass plate and hold it vertically. Observe it.
a) If the drop of milk remains sticking on the glass plate or move down slowly leaving being a white trail, then the milk sample is pure.