QUICK TESTS FOR SOME ADULTERANTS IN FOOD

 

P R E F A C E

M I L K  &  M I L K   P R O D U C T S

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P R O D U C T S

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M I S C E L L A N E O U S   F O O D S

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D E V E L O P I N G   A  S I M P L E 
K I T

P R E C A U T I O N S  T O  B E  T A K E N

MISCELLANEOUS FOODS
Name of Food Article Adulterant

Simple Method for detection of Common Adulterants

 Remarks
Common Salt









Tea Leaves















Coffee





White powdered stone







Exhausted tea or tur or gram dal husk with colour










Iron filings

Chicory






Tamarind seeds powder and date seed powder 		saffron is prepared by soaking maize cob in sugar and colouring it with coal tar colour. the colour dissolves in after if artificially coloured. A bit of pure saffron when allowed to dissolved in water will continue to give its saffron colour so long as it lasts.

Stir a spoonful of sample of salt in a glass of water. The presence of chalk will make solution white and other insoluble impurities will settle down.

Take a filter paper and spread a few tea leaves. Sprinkle with water to wet the filter paper. If coal tar immediately stain the filter paper. Wash the filter paper under tap water and observe the stains against light.

Spread a little slaked lime on white porcelain tile or glass plate, sprinkle a little tea dust on the lime. Red, orange or other shades of colour spreading on the lime will show the presence of coal tar colour. In case of genuine tea, there will be only a slight greenish yellow colour due to chlorophyll, which appear after some time.

By moving a magnet through the sample, iron fillings can be separated.

Gently sprinkle the coffee powder sample on the surface of water in a glass. The coffee floats over the water but chicory begins to sink down within a few seconds. The falling chicory powder particles leave behind them a trail of colour, due to large amount of caramel.

Sprinkle the suspected coffee powder on white filter/blotting paper and spray 1 percent sodium carbonate solution on it. Tamarind and date seed powder will, if present, stain blotting paper/filter paper red. 		 
Supari Pan Masala



Catachu Powder

Silver Leaves		 Colour

Saccharin


Chalk


Aluminium leaves		 Colour dissolves in water.

Saccharin gives excessive and lingering sweet taste and leaves bitter taste at the end.

Chalk gives effervescence (gives off bubbles) with concentrated Hydrochloric acid.

i. On ignition, genuine silver leaves burn away completely, leaving glistering white spherical ball of the same mass whereas aluminium leaves are reduced to ashes of dark grey blackish colour.

ii. Take silver leaves in test tube, add diluted Hydrochloric acid. Appearance of turbidity to white precipitate indicates the presence of silver leaves. Aluminium leaves do not give any turbidity or precipitate.

iii. Take a small portion of metal leaves and add a few drops of concentrated Nitric acid. Silver leaves will completely dissolve whereas aluminium leaves will remain undissolved.




This test is only for chalk.
Vinegar Mineral acid Test with the Metanil yellow indicator paper, in case, the colour changes from yellow to pink, mineral acid is present. See Appendix-I.