Detection of Mashed Potatoes and Other starches in Desi Ghee:
Experiment No- 10
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Mashed Potato |
- 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.
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Detection of Blotting paper in Rabri:
Experiment No- 9
- Take a teaspoon of rabri in a test tube. Add 3 ml of hydrochloric acid and 3 ml of distilled water.
- Stir the content with a glass rod. Remove the rod and examine.
- Presence of fine fibres to the glass rod will indicate the presence of blotting paper in rabri.
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blotting paper as adulterant in Rabri |
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Detection of Vegetable oil in Sweet Curd:
Experiment No- 8 of 1
- Take 1 teaspoon full of curd in a test tube.
- Add 10 drops of hydrochloric acid. Mix up the contents shaking the test tube gently.
- After 5 minutes, examine the mixture. The red colouration indicates the presence of vanaspati in the curd.
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Red- positive Negative |
Detection of Vanaspathy or Margarine in Desi Ghee and Butter:
Experiment No- 8 of 2
- Take 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 Mrgarine. 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 present
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Detection Coal Tar Dye in Ghee, Cheese, Khoa, Condensed milk & Powder :
Experiment No- 7:
- Add 5 ml of dil. H2SO4 or concentrated HCL to one teaspoon full of melted sample in a test tube. Shake well.
- Pink colour (in case of H2SO4) or crimson colour (in case of HCl) indicates coal tar dyes.
- If HCl does not give colour dilute it with water to get the colour.
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Coal Tar Dye
Adulterant / Purpose of Adulteration: Coal tar Dye easily available at department store / Color make the product attractive and look like Pure product.
Loss/Health Effect: Brain Disorder and cancer.
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Experiment No- 6 : Detection of Synthetic milk
& Protein in Milk
- Synthetic milk has a bitter
after taste, gives a soapy feeling on rubbing between the fingers and
turns yellowish on heating.
- The milk can easily be tested
by Urease strips (available in the Medical stores) because Synthetic milk
is devoid of protein.
Source / Purpose of Adulteration: Urea is used as synthetic protein, easily available
on Agricultural store as a fertilizer/protein is calculated by % of Nitrogen present in milk, due to the
presence of Nitrogen of Urea, on analysis milk given higher value than actual
value, that’s why milk supplier mix urea.
Loss/Health Effect: Failure of Kidney, Damage Heart
and Liver
Experiment No- 5: Detection of Formalin in Milk
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Formalin in Milk |
- Take 10 ml of milk in a tests tube and add 5 ml of concentrated sulphuric acid from the sides of the wall without shaking.
- If a violet or blue ring appears at the intersection of two layers then it shows presence of formalin.
Adulterant / Purpose of Adulteration: Formalin chemical available at chemical supplier for the purpose of preservation of dead materials/ Formalin enhances the life of milk and thus is added for preservation purpose.
Loss/Health Effect: Irritation and cancer.
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Left- Preservation, Right- Analysis of Formalin |
Experiment No- 4: Detection of Vegetable oil (Vanaspati) in Milk
- Take 3 ml of milk in a test tube.
- Add 10 drops of hydrochloric acid. Mix up one teaspoonful of sugar.
- After 5 minutes, examine the mixture.
- The red colouration indicates the presence of Vegetable oil in the milk.
Loss/Health Effect: Monetary loss, elevate cholestrol, diabetes and coronary ailments.
Source/ Purpose of Adulteration: Vegetable oil / Decrease the Manufacturing cost and increase fat %.
Experiment No- 3 of 1: Detection of Urea in Milk
- Take a full teaspoon of milk in a test tube.
- Add ½ teaspoon of soybean or arhar /Pigeon pea (Cajanus cajan) powder.
- Mix up the contents thoroughly by shaking the test tube.
- After 5 minutes, dip a red litmus paper in it. Remove the paper after 30 seconds.
- A change in colour from red to blue indicates the presence of urea in milk.
Source / Purpose of Adulteration: Urea is easily available on Agricultural store as a fertilizer/ The Protein content is calculated by converting Nitrogen present in a milk. Urea being a rich source of Nitrogen is generally used to increase protein content in the milk. On testing protein coming from Urea will make a milk look as it contains lot of proteins.
Loss/Health Effect: Failure of Kidney, Damage Heart and Liver
Experiment No- 2: Detection of Added Starch in Milk
- Take full tea spoon (2 ml) milk in test tube.
- Add 2-5 drops of Iodine tincture or Iodine solution.
- Within few second formation of blue color indicates the presence of added starch in milk.
- The solution of iodine is easily available in the medical stores.
Source / Purpose of Adulteration: Starch is easily available at departmental store / Increase the Thickness of Milk and give Pseudo filling of higher quality milk.
Loss/Health Effect: Dental caries, Excessive intakes may displace nutrients and contribute to Obesity. Monetary loss
Experiment No- 1:
Detection of Excess Water an adulterant in Milk
- One drop of milk putting an upper portion of polished slanting surface.
- A drop of pure milk flows slowly and leaving a white trail behind it.
- Whereas milk adulterated with water will flow immediately without leaving a mark or light mark.
Source/ Purpose of Adulteration: Tap Water(may be contaminated) / To Increase the volume of Milk.
Loss/Health Effect: Monetary loss, Contamination with water
In Short:
Experiment No- 1 Water as adulterant in Milk
- The presence of water can be by putting a drop of milk on a polished slanting surface. The drop of pure milk either or flows lowly leaving a white trail behind it, whereas milk adulterated water will flow immediately without leaving a mark.
Experiment No- 2 Detection of Starch in Milk
- Add a few drops of tincture of Iodine or Iodine solution. Formation of blue colour indicates the presence of starch.Iodine solution is easily available in the medical stores
Experiment No- 3 Detection of Urea in Milk
- Take a teaspoon of milk in a test tube. Add ½ teaspoon of soybean or arhar powder. Mix up the contents thoroughly by shaking the test tube. After 5 minutes, dip a red litmus paper in it. Remove the paper after ½ a minute. A change in colour from red to blue indicates the presence of urea in the milk.
Experiment No- 4 Detection of Vanaspati in Milk
- Take 3 ml of milk in a test tube. Add 10 drops of hydrochloric acid. Mix up one teaspoonful of sugar. After 5 minutes, examine the mixture. The red colouration indicates the presence of vanaspati in the milk.
Experiment No- 5 Detection of Formalin in Milk
- Take 10 ml of milk in a tests tube and add 5 ml of con sulphuric acid from the sides of the wall without shaking. If a violet or blue ring appears at the intersection of two layers then it shows presence of formalin.
- Formalin enhances the life of milk and thus is added for preservationpurpose.
Experiment No- 6 Detection of Synthetic milk & Protein in Milk
- Synthetic milk has a bitter after taste, gives a soapy feeling on rubbing between the fingers and turns yellowish on heating
- The milk can easily be tested by Urease strips (available in the Medical stores) because Synthetic milk is devoid of protein.
Experiment No- 7 Detection of Glucose/Inverted Sugar & Protein in Milk
- Milk does not contain glucose /invert sugar, if test for glucose with urease strip found positive. It means milk is adulterated.
- If it is made synthetically by adding while colour water paint. Oils, alkali, urea and detergent etc. Glucose, inverted sugar syrup is added in milk to increase the consistency and test.
Experiment No- 8 Detection Coal Tar Dye in Ghee, Cheese, Khoa, Condensed milk & Powder
- Add 5 ml of dil. H2SO4 or conc. HCL to one teaspoon full of melted sample in a test tube. Shake well. Pink colour (in case of H2SO4) or crimson colour (in case of HCl) indicates coal tar dyes. If HCl does not give colour dilute it with water to get the colour.
Experiment No- 9 Detection of Vanspati in Sweet Curd
- Take1 teaspoon full of curd in a test tube. Add 10 drops of hydrochloric acid. Mix up the contents shaking the test tube gently. After 5 minutes, examine the mixture. The red colouration indicates the presence of vanaspati in the curd.
Experiment No- 10 Detection of Blotting paper in Rabdi
- Take a teaspoon of rabri in a test tube. Add 3 ml of hydrochloric acid and 3 ml of distilled water. Stir the content with a glass rod. Remove the rod and examine. Presence of fine fibres to the glass rod will indicate the presence of blotting paper in rabri.
Experiment No- 11 Detection of Starch in Khoa and its products
- Boil a small quantity of sample with some water, cool and add -a few drops of Iodine solution. Formation of blue colour indicates the presence of starch
Experiment No- 12 Detection of Starch in Chhana or Paneer
- Boil a small quantity of sample with some water, cool and add a few drops of Iodine solution. Formation of blue colour indicates the presence of starch.
Experiment No- 13 Detection of Vanaspathy or Margarine in Desi Ghee
- Take 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 Mrgarine. 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 present
Experiment No- 14 Detection of Mashed Potatoes and Other starches in Desi Ghee
- 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.
Experiment No- 14 Detection of Vanaspathy or Margarine in Butter
- Take 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 Mrgarine. 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 present