| Food | Red chilli powder |
| Adulterant | Rhodamine B colour |
| Detection |
Take a little amount (one-fourth of a tea-spoon) of the sample in a test tube. Add in it 3 ml of distilled water and 10 drops of carbon tetrachloride. Shake the tube vigorously to mix up the contents. The disappearance of red colour as a result of the shake and reappearance of the same colour after addition of a drop of hydrochloric acid indicate the use of Rhodamine B colour in red chilli powder. |
| Food | Mustard Oil |
| Adulterant | Argemone Oil |
| Detection | Take a little amount (3 ml) of the sample in a test tube. Add 20 drops of nitric acid. Heat the tube on the flame of a spirit lamp for 3 minutes. A red colouration indicates the presence of argemone oil in mustard oil. |
| Food | Mustard Oil |
| Adulterant | Cotton seed oil |
| Detection | Take a small quantity (3 ml) of the sample in a test tube. Add in it 2 ml of amyl alcohol, 1 ml of carbon disulphide and a little amount of sulphur. Plug the mouth of the test tube and heat the tube on the flame of a spirit lamp for 3 minutes. A red colouration indicates the presence of cotton seed oil in mustard oil. |
| Food | Mustard Oil |
| Adulterant | Mineral oil |
| Detection | Take a little amount (3 ml) of the sample in a test tube. Add 20 drops of alcoholic potash. Heat the tube on the flame of a spirit lamp for 3 minutes to effect decolourization of the mixture. Add 10 drops of distilled water and shake the tube. Examine the tube to trace turbidity. Continue the operation of adding water upto 15 ml and the examination of the tube for appearance of turbidity. The appearance of turbidity indicates the presence of mineral oil in mustard oil. |
| Food | Mustard Oil |
| Adulterant | Castor oil |
| Detection | Take a little amount (3 ml) of the sample in a test tube. Add 2 ml of petroleum ether. Shake the tube to mix up the contents thoroughly. Keep the tube immersed in a salt-ice mixture or in a pot of cold saline water. Examine the tube after 5 minutes. The appearance of turbidity in mixture indicates the presence of castor oil in mustard oil. A similar test may be made to detect adulteration of mustard oil with coconut oil, or dalda. |
| Food | Edible Oil |
| Adulterant | Prohibited colour |
| Detection | Take a little amount (20 drops) of the sample in each of 4 test tubes. Prepare 3 different solutions, mixing up 1 part of distilled water, 3 parts of distilled water and 4 parts of distilled water. Add 2 ml of each solution in each of 3 test tubes and add 2 ml of hydrochloric acid in the fourth test tube. Shake each tube to mix up the contents thoroughly. A rosy colouration in the mixture of any tube indicates the presence of prohibited colour in edible oil. |
| Food | Edible Oil |
| Adulterant | Cyanide |
| Detection | Take a little amount (3 ml) of the sample in a test tube. Add 10 drops of alcoholic potash and heat the tube on the flame of a spirit lamp. Make an addition of a little amount of each of ferrous sulphate and ferric chloride in the test tube and shake it to mix up the contents thoroughly. Add 3 ml of hydrochloric acid. A blue colouration indicates the presence of hydrocyanic acid which gets produced due to presence of cyanide in edible oil. |
| Food | Edible Oil |
| Adulterant | Mobil oil |
| Detection | Take a little amount (20 drops) of the sample in a test tube. Add 10 drops of alcoholic potash. Heat the tube on the flame of a spirit lamp to decolourize the mixture. Add 10 drops of dichloroquinol chloride. Heat the tube again. The appearance of blue colour indicates the presence of a compound of triorthocrysyle phosphate (TOCP) which contributes to incidence of paralysis. Traces of this compound in edible oil to an admixture of edible oil with mobil oil. |
| Food | Edible Oil |
| Adulterant | Rancidity |
| Detection | Take a little amount (3 ml) of the sample in a test tube. Add in it 3 ml of hydrochloric acid. Plug the mouth of the test tube. Shake the tube to mix up the contents thoroughly. Add 3 ml of 0.1% phloroglucinol solution in ether. Shake the tube vigorously for 2 minutes and keep it aside. Examine the tube after half an hour. A red or pink colouration in acid layer indicates that the oil sample in rancid. |
| Food | Soda lemonade |
| Adulterant | Mineral acid |
| Detection | Pour 2 drops of the sample on a metanil yellow paper strip. A violet colouration indicates the presence of mineral acid in aerated water. The colour impression gets retained even after drying the paper. (Prepare metanil yellow paper strips by soaking filter paper strips in 0.1% aqueous solution and drying the paper strips). |
| Food | Milk |
| Adulterant | Sodium bicarbonate |
| Detection | Take a little amount (3 ml) of the sample in a test tube. Add 10 drops of rosalic acid solution. A rosy colouration indicates the presence of sodium bicarbonate in milk. |
| Food | Milk |
| Adulterant | Sugar |
| Detection |
Take a
little amount (3 ml) of the sample in a test tube. Add in it 2 ml
of hydrochloric acid or muratic acid. Heat the tube after adding a
bit (50 mg) of resorcinol. A red colouration indicates the use of
sugar in milk. |
| Food | Milk |
| Adulterant | Glucose |
| Detection |
Take a little amount (5 ml) of the sample in a test tube. Dip a strip of diastix in it for half a minute. A change in colouration from blue to green indicates the presence of glucose in milk. |
| Food | Milk |
| Adulterant | Cereal starch |
| Detection | Take a little amount (3 ml) of the sample in a test tube. Add a drop of 1% aqueous solution of iodine. A blue or deep blue colouration indicates the use of cereal starch in milk. |
| Food | Milk |
| Adulterant | Urea |
| Detection |
Take a little amount (5 ml) of the sample in a test tube. Add a little amount (a half of a tes-spoon) of soyabean or arhar powder. Shake the tube to mix up the contents thoroughly. After 5 minutes, dip a red litmus paper in it. Lift the paper after 30 seconds. A change in colour from red to blue indicates the use of urea in milk. |
| Food | Milk |
| Adulterant | Boric acid |
| Detection | Take a little amount (3 ml) of the sample in a test tube. Add 20 drops of hydrochloric acid and shake the tube to mix up the contents thoroughly. Dip a yellow paper strip and lift the same after a minute. A change in colour from yellow to red followed by a change from red to green by addition of drop of ammonia solution indicates the presence of boric acid in milk. (To prepare yellow paper strips, dip strips of filter paper in an aqueous solution of turmeric and dry it up). |
| Food | Milk |
| Adulterant | Dalda |
| Detection |
Take a little amount (3 ml) of the sample in a test tube. Add 10 drops of hydrochloric acid or muratic acid. Mix up a little amount (one-fourth of a tea-spoon) of sugar. Examine the mixture after 5 minutes. A red colouration indicates the use of dalda in milk. |
| Food | Sweet curd |
| Adulterant | Dalda |
| Detection | Take a little amount (5 ml) of the sample in a test tube. Add 10 drops of hydrochloric acid or muratic acid. Shake the tube gently to mix up the contents. Examine the mixture after 5 minutes. A red colouration indicates the use of dalda in sweet curd. |
| Food | Rabri, a sweetmeat prepared by condensing the films of milk. |
| Adulterant | Blotting paper |
| Detection | Take a small quantity (1 tea-spoon) of the sample in a test tube. Add 3 ml of hydrochloric acid or murateic acid and 3 ml of distilled water. Stir the contents with a glass rod. Lift the rod and examine. Adherence of finer fibres to the rod indicates the presence of blotting paper in rabri. |
| Food | Ghee |
| Adulterant | Dalda |
| Detection |
Take a little amount (3 ml) of the sample in a test tube. Add 10 drops of hydrochloric acid or muratic acid and a little amount (one-fourth of the tea-spoon) of sugar. Shake the tube to mix up the contents thoroughly. Examine the tube after 5 minutes. A red colouration indicates the presence of Dalda in Ghee. |
