Question

simple method of spotting the adulteration in foodstuff

Answer 1

Oil and Fats

S. NoFood ArticleAdulterantMethod for DetectionRemarks1GheeVanaspathy or MargarineTake about one tea spoon full of melted sample of Ghee with equal quantity of concentrated Hydrochloric acid in a stoppered test tube and add to it a pinch of sugar. Shake for one minute and let it for five minutes. Appearance of crimson colour in lower (acid) of Vanaspati or Margarine.The test is specific for seasame oil
Which is compulsorily added to Vanaspati and Margarine.
Some coal tar colours also give a positive test.
If the test is positive i.e. red colour develops only by adding strong
Hydrochloric acid (without adding crystals of sugar) then the sample is adulterated with coal tar dye. If the crimson or red colour develops after adding and shaking with sugar, then alone Vanaspati or Margarine is present2Mashed Potatoes, Sweet Potatoes and other starches.The presence of mashed potatoes and sweet potatoes in a sample of ghee can easily be detected by adding a few drops of Iodine, which is brownish in colour turns to blue if mashed potatoes/sweet potatoes/other starches are present.3ButterVanaspati or MargarineTake about one teaspoon full of melted sample of butter with equal quantity of concentrated Hydrochloric acid in a stoppered test tube and add to it a pinch of sugar. Shake for one minute and let it for five minutes. Appearance of crimson colour in lower (acid) of Vanaspati or Margarine.The test is specific for seasame oil which is compulsorily added to Vanaspati and Margarine. Some coal tar colours also give a positive test.

If testis positive i.e. red colour develops only by adding strong Hydrochloric acid (without adding crystals of sugar) then the sample is adulterated with coal tar dye. If the crimson or red colour develops after adding and shaking with sugar, then alone Vanaspati or Margarine is present
4Mashed Potatoes and other starchesThe presence of mashed potatoes and sweet potatoes in a sample of butter can easily e detected by adding a few drops of iodine (which is brownish in colour), turns to blue.5Edible oilProhibited colour
Take 5 ml of sample in a test tube and add 5 ml of concentrated hydrochloric acid. Shake gently, let it stand for 5 minutes. Colour will separate in the upper layer of the solution.
6Coconut oilAny other oilPlace a small bottle of oil in refrigerator. Coconut oil solidifies leaving the adulterant as a Separate layer.

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