| Food | Tea Leaves |
| Adulterant | Iron Flakes |
| Detection | Spread a small quantity (2 tea-spoon) of the sample on a piece of paper. Draw a magnet over it. Iron flakes, if present, cling to the magnet. The same test may be carried out to trace iron flakes from tea half-dust and iron filings from tea dust. |
| Food | Tea Leaves |
| Adulterant | Leather Flakes |
| Detection | Prepare a paper-ball. Fire the ball and drop a little amount of the sample on it. The presence of leather flakes emits an odour of burnt leather. |
| Food | Tea Leaves |
| Adulterant | Coal Tar Dye |
| Detection | Scatter a little amount (1 tea-spoon) of the sample on a moistened white blotting paper. After 5 minutes, remove the sample and examine the paper. A revelation of coloured spots indicates the use of the dye. |
| Food | Coriander powder and Cumin Powder |
| Adulterant | Saw Dust |
| Detection | Take a little amount (a half of tea-spoon) of the sample. Sprinkle it on water in a bowl. Spice powder gets sedimented at the bottom and saw-dust floats on the surface. |
| Food | Green vegetables like Bitter Gourd, Green Chilli and others |
| Adulterant | Malachite Green |
| Detection | Take a small part of the sample and place it on a piece of moistened white blotting paper. The impression of colour on the paper indicates the use of malachite green, or any other low priced artificial colour. |
| Food | Arhar Pulse |
| Adulterant | Kesarri Pulse |
| Detection | Kesari Pulse has a characteristic wedge shape. Larger Kesari resembles Arhar (Tur). It can be separated by visual examination. |
| Food | Black Pepper |
| Adulterant | Papaya Seeds |
| Detection | Papaya seeds do not have any smell and are relatively smaller in size. Adulteration of papaya seed with Black Pepper may be detected by way of visual examination as also by way of smelling. |
| Food | Rice |
| Adulterant | Earth, sand, grit, unhusked paddy, rice bran, talc, etc. |
| Detection | These adulterants may be detected visually and removed by way of sorting, picking, and washing. |
| Food | Wheat |
| Adulterant | Earth, sand, grit, chopped straw, bran, unhusked grain, and seeds of weeds. |
| Detection | These adulterants may be detected visually and removed by way of sorting, picking, and washing. |
|
CHEMICAL TEST |
|
| Food | Coffee powder |
| Adulterant | Cereal starch |
| Detection | Take a small quantity (one-fourth of a tea-spoon) of the sample in a test tube and add 3 ml of distilled water in it. Light a spirit lamp and heat the contents to colourize. Add 33 ml of a solution of potassium permanganate and muratic acid (1:1) to decolourize the mixture. The formation of blue colour in mixture by addition of a drop of 1% aqueous solution of iodine indicated adulteration with starch. |
| Food | Coffee powder |
| Adulterant | Powder of scorched persimmon stones |
| Detection | Take a small quantity (1 tea-spoon) of the sample and spread it on a moistened blotting paper. Pour on it, with much care, 3 ml of 2% aqueous solution of sodium carbonate. A red colouration indicates the presence of powder of scorched persimmon stones in coffee powder. |
| Food | Jaggery |
| Adulterant | Sodium bicarbonate |
| Detection | Take a little amount (one-fourth of a tea-spoon) of the sample in a test tube. Add 3 ml of muratic acid. The presence of sodium carbonate or sodium bicarbonate effects effervescence. |
| Food | Jaggery |
| Adulterant | Metanil yellow colour |
| Detection |
Take a little amount (one-fourth of a tea-spoon) of the sample in a test tube. Add 3 ml of alcohol and shake the tube vigorously to mix up the contents. Pour 10 drops of hydrochloric acid in it. A pink colouration indicates the presence of metanil yellow colour in jaggery. |
| Food | Asafoetida |
| Adulterant | Resin and colour |
| Detection |
Take a little amount of small parts of the sample in test tube. Add 3 ml of distilled water and shake the tube gently. Pure asafoetida dissolves in water very quickly and produces a milky white colour, but in case of adulteration with a chemical colour the mixture turns to be coloured. The purity of asafoetida may also be examined by taking a little amount of it on the tip of a force and placing the same on the flame of a spirit lamp. Asafoetida burns quickly, producing bright flame and leaving the impurities behind. |
| Food | Gram powder |
| Adulterant | Kesari powder |
| Detection |
Take a little amount (a half of a tea-spoon) of the sample in a test tube with 3 ml of distilled water. Add 3 ml of muratic acid. Immerse the tube in warm water. Check the tube after 15 minutes. A violet colouration indicates the presence of Kesari powder in Gram powder. |
| Food | Gram powder |
| Adulterant | Metanil yellow colour |
| Detection |
Take a small quantity (a half of a tea-spoon) of the sample in a test tube. Add 3 ml of alcohol. Shake the tube to mix up the contents thoroughly. Add 10 drops of hydrochloric acid in it. A pink colouration indicates adulteration of gram powder with metanil yellow. |
| Food | Processed food, sweetmeat or syrup |
| Adulterant | Rhodamine B colour |
| Detection |
The presence of this chemical colour
in food is very easy to detect as it shines very brightly under
sun. A more precise methods of detection is also there.
|
| Food | Processed food, sweetmeat or syrup |
| Adulterant | Metanil Yellow |
| Detection |
Take little amount (a half of a tea-spoon) of the sample in a test tube. Add 10 drops of muratic acid or hydrochloric acid in it. The appearance of rosy colour indicates adulteration of food with metanil yellow. |
| Food | Parched rice |
| Adulterant | Urea |
| Detection | Take 30 pieces of parched rice in a test tube. Add 5 ml of distilled water. Shake the tube to mix up the contents thoroughly. After 5 minutes, filter water contents and add to it a little amount (a half of a tea-spoon) of powder of arhar or soyabean. Wait for another 5 minutes and then dip a red litmus paper in the mixture. Lift the paper after 30 seconds and examine it. A blue colouration indicates the use of urea in parched rice. |
| Food | Turmeric powder |
| Adulterant | Metanil Yellow colour |
| Detection |
Take a little amount (one-fourth of a tea-spoon) of the sample in a test tube. Add 3 ml of alcohol. Shake the tube to mix up the contents thoroughly. Add 10 drops of muratic acid or hydrochloric acid in it. A pink colouration indicates the use of metanil yellow colour in turmeric powder. |
| Food | Green vegetable like green chilli etc. |
| Adulterant | Malachite Green |
| Detection |
Rub the outer green surface of a small part of the sample with a liquid paraffin soaked cotton. The sample is adulterated when the white cotton turns green. |
| Food | Dry red chilli |
| Adulterant | Rhodamine B colour |
| Detection |
Take a red chilli from the sample and rub the outer surface with a piece of cotton soaked in liquid paraffin. The sample is adulterated if the cotton becomes red. |
| Food | Dry turmeric root |
| Adulterant | Metanil yellow colour |
| Detection |
Take a piece of dry turmeric root and rub the outer surface with a piece of cotton soaked in liquid paraffin. A yellow colouration of cotton indicates adulteration of turmeric root with metanil yellow colour. |
| Food | Sweet potato |
| Adulterant | Rhodamine B colour |
| Detection | Take a small part of the sample and rub the red outer surface with a piece of cotton soaked in liquid paraffin. The cotton adhering colour indicates the use of Rhodamine B colour on outer surface of the sweet potato. |
