How to Check Food Adulteration

Food adulteration is the addition or subtraction of any substance to or from food, so that the natural composition and quality of food substance is affected


Detecting presence of water
  • Put a drop of milk on polished slanting surface
  • Pure milk either stays or flows slowly, leaving a white trail behind
  • Milk adulterated with water will flow immediately without leaving a mark
Detecting presence of detergent
  • Take equal parts of milk and water. Shake thoroughly
  • If adulterated, dense lather will form
  • Pure milk will form a thin layer of foam


Detecting mashed potato, sweet potato and other starches
  • Take half teaspoon of ghee/butter, add 2-3 drops of tincture of iodine
  • Blue colour indicates starch adulteration
Detecting other oils in coconut oil
  • Place oil in refrigerator (not freezer) for 30 minutes
  • Coconut oil will solidify


Detecting malachite green in green vegetables
  • Rub the outer surface of a small part of the green vegetable with cotton soaked in water or oil
  • If the cotton turns green, then it is adulterated
Detecting green colour in green peas
  • Place a few green peas in a glass of water
  • Let them stand for half an hour
  • Clear separation of colour in water indicates adulteration


Detecting adulterants in chilli powder
  • Add a teaspoon of the powdered spice to a glass of water and examine the residue
  • A gritty residue indicates presence of brick powder or sand
  • If residue is smooth but soapy, soap stone is present
  • If sawdust is present, it will float
Detecting foreign resin in asafoetida (hing)
  • Burn a small quantity of asafoetida in a stainless steel spoon
  • The pure spice will burn with a bright flame like camphor
Papaya seeds in black pepper
  • Place a few corns of black pepper in water. Papaya seeds will float


Detecting presence of used leaves in fresh tea leaves
  • Spread few tea leaves on a filter paper
  • Sprinkle with water to wet the filter paper
  • Wash the filter paper under tap water and observe the stains against light
  • Pure tea leaves will not stain the filter paper
  • If coal tar is present, it will immediately stain the filter paper
Chicory in coffee
  • To a glass of water add a teaspoon of coffee powder
  • Coffee powder will float while chicory will sink

 Wheat Flour

Detecting adulteration
  • When dough is prepared from pure flour, less water is needed
  • Chapatis will taste somewhat sweetish. Those prepared from adulterated flour are tasteless


Detecting presence of chalk
  • Stir a spoonful of salt in a glass of water
  • If chalk is present, the water will turn white. Other insoluble impurities will settle down