How to Test Coriander Seeds for Adulteration (Horse Dung Powder, Ergot, Sulfur Dioxide)

Coriander Seeds (Coriandrum sativum), known as Dhania, are targets for horrific adulterants like horse dung powder and toxic ergot seeds. To make old seeds look fresh, they are often bleached with sulfur or dyed with lead-based chemicals. Consuming these can lead to severe infections and neurological damage.

1. The Water Float and Odor Test:
Add a spoonful of seeds to a glass of water. If you see powdery particles floating on the surface that release a foul, animal-like odor, it confirms the presence of horse dung powder. Pure coriander seeds will mostly stay submerged and have a fresh, citrusy aroma.

2. The Visual Ergot Check:
Spread the seeds on a white plate and look for dark, curved, cigar-shaped grains that are slightly larger than the round coriander seeds. These are Ergot—a parasitic fungus that is highly toxic and can cause ergotism. If found, the entire batch must be discarded.

3. The Sulfur Sniff Test:
If the seeds look unnaturally pale or golden-white, smell them closely. A pungent, chemical, or matchstick-like odor indicates sulfur dioxide bleaching used to make old, moldy seeds appear new.

4. The Crush and Oil Check:
Crush a few seeds between two pieces of clean white paper. Pure coriander seeds will release a tiny amount of natural oil and a strong aroma. If the paper remains dry and shows dark or grayish powdery streaks, it indicates the presence of sawdust or dung fillers.

5. The Color Bleed Test:
Soak seeds in warm water. If the water turns bright yellow or green, the seeds have been artificially dyed with industrial colorants. Natural coriander will only give a very pale, yellowish tint to the water after significant time.