Project for class 12th chemistry

1. Introduction
What is Adulteration ?
“Adulteration of food means substitution of the genuine food material wholly or in part with
any cheaper or inferior substance or removal of any of its constituents, wholly or in part,
which affects adversely the nature , substance or quality of the food.”
Adulteration is the act of intentionally debasing the quality of food offered for sale either by
mixture or substitution of inferior substances or by the removal of some valuable
ingredient. Adulteration in food is normally present in its most crude form; Prohibited
substances are either added or partly or wholly substituted. Normally the
contamination/adulteration in food is done either for financial gain or due to carelessness
and lack in proper hygienic condition of processing, storing, transportation and marketing.
This ultimately results that the consumer is either cheated or often become victim of
diseases. Such types of adulteration are quite common in developing countries or backward
countries. It is equally important for the consumer to know the common adulterants and
their effect on health.
In past few decades adulteration of food has become one of the most serious
problems.Consumption of adulterated food causes diseases l ike cancer, asthma, ulcer, etc.
Majority of adulterants used by the shopkeepers are cheap substitutes which are easily
available.

2. Historical Background
Historically, the use of adulterants has been common; sometimes dangerous substances
have been used. In the United Kingdom during the Victorian era, adulterants were
common; for example, cheeses were sometimes colored with lead. Similar adulteration
issues were seen in industry in the United States, during the 19th century. There is dispute
over whether these practices declined primarily due to government regulation or to
increased public awareness and concern over the practices. In the early 21st century, cases
of dangerous adulteration occurred in the People's Republic of China.
Frederick Accum Arthur Hill Hassall
Adulterant use was first investigated in 1820 by the German chemist Frederick Accum, who
identified many toxic metal colorings in food and drink. His work antagonized food
suppliers, and he was ultimately discredited by a scandal over his alleged mutilation of
books of the Royal Institution library. The physician Arthur Hill Hassall conducted
extensive studies in the early 1850s, which were published in The Lancet and led to the 1860
Food Adulteration Act and other legislation.[3]
At the turn of the 20th century, industrialization in the United States led to a rise in
adulteration which inspired some protest. Accounts of adulteration led the New York
Evening Post to parody:
“Mary had a little lamb,
And when she saw it sicken,
She shipped it off to Packingtown,
And now it's labeled chicken.”
A history of food poisoning and adulteration is given in the textbook, Death in the Pot: The
Impact of Food Poisoning on History.

3. Theoretical Background
We are very fortunate to be born a country which is blessed with rich soil, diversified
climate, many rivers and the great Himalayas where almost all varieties of fruits, vegetables
and cereals, etc. can be grown. In ancient times, the land was in abundance, the supply of
food was more than the demand and people used fresh food materials in most natural form.
The population spurt in our country has given rise to unemployment and poverty.
The demand for food has increased & our country has to import food grains, oil etc. from
other countries. This shortage of food and ignorance of consumers is the main cause for
adulteration of foodstuffs by the unscrupulous traders. It has become so common that the
consumers have to run from pillars to pillars to get a foodstuff which is not adulterated. The
consumers are not aware of hazards of adulteration and pay heavily for consuming
adulterated food. If the consumer knows the ways and means to check the commodities of
daily use, they can save themselves and their fami lies from this mind-boggling problem.
The increasing number of food producers and the outstanding amount of import foodstuffs
enables the producers to mislead and cheat consumers. To differentiate those who take
advantage of legal rules from the ones who commit food adulteration is very difficult. The
consciousness of consumers would be crucial.
Ignorance and unfair market behavior may endanger consumer health and misleading can
lead to poisoning. So we need simple screening, tests for their detection. In the past few
decades, adulteration of food has become one of the serious problems. Consumption of
adulterated food causes serious diseases like cancer, diarrhea, asthma, ulcers etc. Majority
of fats, oils and butter are paraffin wax, castor oil and hydrocarbons. Red chili powder is
mixed with brick powder and pepper is mixed with dried papaya seeds. These adulterants
can be easily identified by simple chemical tests.

4. Certain Govt. Measures To
Check Corruption
Adulteration of food-stuffs was so rampant, widespread and persistent that nothing short of
a somewhat drastic remedy in the form of a comprehensive legislation became the need of
the hour.
To check this kind of anti -social evil a concerted and determined onslaught was launched by
the Government by introduction of the Prevention of Food Adulteration Bill in the
Parliament to herald an era of much needed hope and relief for the consumers at large.
‘Adulteration of food-stuffs and other goods’ is now included in the Concurrent List (III) in
the Constitution of India. It has, therefore, become possible for the Central Government to
enact an all India legislation on this subject. The Bill replaces all local food adulteration
laws where they exist and also applies to those States where there are no local laws on the
subject. Among others, it provides for —
(i) a Central Food Laboratory to which food samples can be referred to for final opinion in
disputed cases (clause 4),
(ii) a Central Committee for Food Standards consisting of representatives of Central and
State Governments to advise on matters arising from the administration of the Act (clause
3), and
(iii) the vesting in the Central Government of the rule-making power regarding standards of
quality for the articles of food and certain other matters (clause 22).
ACT 37 OF 1954
The Prevention of Food Adulteration Bill was passed by both the house of Parliament and
received the assent of the President on 29th September, 1954. It came into force on Ist June,
1955 as THE PREVENTION OF FOOD ADULTERATION ACT, 1954 (37 of 1954).
LIST OF ADAPTATION ORDER AND AMENDING ACTs
1. The Adaptation of Laws (No.3) Order, 1956.
2. The Prevention of Food Adulteration (Amendment) Act, 1964 (49 of 1964).
3. The Prevention of Food Adulteration (Amendment) Act, 1971 (41 of 1971).
4. The Prevention of Food Adulteration (Amendment) Act, 1976 (34 of 1976).
5. The Prevention of Food Adulteration (Amendment) Act, 1986 (70 of 1986).

5. Several agencies have been set up by the Government of India to remove adulterants from
food stuffs
 Food Safety and Standards Authority of India- The Food Safety and Standards
Authority of India (FSSAI) is an agency of the Ministry of Health & Family Welfare,
Government of India. The FSSAI is responsible for protecting and promoting public
health through the regulation and supervision of food safety
 AGMARK – Acronym for agricultural marketing. This organization certifies food
products for their quality. Its objective is to promote the Grading and Standardization
of agricultural and allied commodities.
 Bureau of Indian Standards {formerly the Indian Standards Institution (ISI)}- The
Bureau of Indian Standards (BIS) is the national Standards Body of India working
under the aegis of Ministry of Consumer Affairs, Food & Public Distribution,
Government of India.
Some Common Adulterants & Diseases Caused by Them-

6. Procedures for testing food adulterants in some of
the food materials-
Experiment- 1st
Aim- To test the presence of water and starch in the given sample of
milk.
Theory-
Addition of water in milk dilutes its fat contents and therefore, lowers its specific density.
Presence of water in milk may be detected by measuring its specific density. Specific density
of pure milk is always more than 1.026. Presence of starch material in milk can be detected
by exploiting the formation of blue-coloured complex with iodine or tincture of iodine.
Materials Required-
Given samples of milk, test tube, lactometer measuring cylinder, sulphuric acid, iodine or
tincture of iodine.

7. Procedure-
(i) Put few drops of the milk sample on a smooth and oily surface. If the milk is pure
then its drops will be stable for some time and leave a white streak.
(ii) Measure the specific density of milk with lactometer
(iii) Babcock Test for Purity of Milk
This determines the fat contents in milk. About 20 mL of milk is taken with the help of
pipette in a small narrow necked graduated flask (as shown in fig. ) and H2SO4 is mixed in
it. The flask is shaken until the mixture becomes dark coloured. The acid does not affect the
fat but it dissolves other solids in milk. The flask is then centrifuged by which the fat if
forced towards the neck, being lighter than other contents. Sufficient warm water is added
to bring the fat in the narrow neck, where its exact percentage is read on the graduation
mark.
(iv) Testing the Presence of Starch in Milk
Take 5 mL of the milk in a test tube. Heat it to almost boiling. Cool and add few drops of
iodine solution or tincture of iodine and shake the contents. Appearance of blue colour in
the sample indicates the presence of starch in the milk. If it is pure, then there will be a deep
yellow colouration due to casein, a protein of milk.
Comment-
Specific density test is not much reliable as specific density of diluted milk can be increased
by addition of some other compounds in it.
Experiment-2nd

8. Aim- To test the presence of adulterants in the given sample of
pure ghee or butter.
Theory-
Starchy matter can be detected with iodine. Iodine forms a blue coloured complex with
starch. Vanaspati ghee gives pink colour with furfural.
Materials Required-
Given sample of ghee or butter, test tube, test tube holder, iodine or tincture of iodine
solution, HCl, sugar etc.
Procedure-
(i) Detection of Starchy Matter
Take about 0.5 g of the given ghee or butter in a test tube. Add about one mL of
water to it and boil. Cool and add a drop of iodine or tincture of iodine solution.
Appearance of blue colour indicates thepresence of starchy matter in the sample.
(ii) Detection of Vanaspatyi Ghee
Take about 0.5 g of the given sample of ghee or butter in a test tube. Heat the tube
gently so that the ghee melts. Add a little sugar and HCl to it. Shake the contents
for 5 minutes. Presence of pink colour in the aqueous layer is the
indication of Vanaspati ghee in the sample.
Comment-
Better results can be obtained by using 2% alcoholic solution of furfural in place of sugar.
Experiment- 3rd
Aim- To check the purity of given sample of oil or fat.

9. Theory-
Oils and fats are mostly adulterated with:
(a) Dyes to improve colour of the material.
(b) Paraffin wax or hydrocarbons to increase the weights of products (vegetable ghee)
(c) Cheap varieties of similar materials e.g. mustard oil is adulterated with Argemone
oil.
The presence of these in fats & oils can be detected by exploiting there characteristic
properties.
Procedure-
(i) Detection of Dyes in Oils & Fats
(a) Take 2 gm. of the melted and filtered fat in a test tube. Add 5 mL of light petroleum
to avoid its solidification and one mL of hydrochloric acid (1:3) to it. Shake the
contents thoroughly and allow it to stand for some time. Appearance of pink colour in
the lower layer wil l indicate the presence of dyes.
(b) Mix 1-2 mL of the fat with same amount of mixture of conc. Sulphuric acid & glacial
acetic acid (in 1:4 ratio) and heat the mixture nearly to boiling. Pink or reddish
colour of the solution will indicate the presence of dyes.
(ii) Detection of Paraffin Wax & Hydrocarbons.
Heat small amount of unsaponifiable matter of oils with acetic anhydride. Droplets of oil
floating on the surface of unused acetic anhydride indicates the
presence of wax or hydrocarbons.
(iii) Detection Of Argemone Oil.
To small amount of oil in a test tube, add few drops of conc. HNO3 and shake. Appearance
of orange or red colour in the acid layer indicates presence of Argemone oil.
(iv) Detection of Mineral Oils

10. To 2 mL of oil in a test tube, add equal amount of N/2 nitric acid and heat the test tube on
water bath. Turbidity in the contents of the test tube indicates the presence of mineral oils
in the given sample.
(v) Detection of Castor Oil
To 2 mL of oil in a test tube, add 4 mL of light petroleum and shake the test tube to get a
clear solution. Now, cool the tube in ice and salt bath. Turbidity in the contents of the test
tube after cooling indicates the presence of mineral oils in the given sample.
Note- (i) Oils catch fire easily so care must be taken while heating them. Better hold the test
tube with a holder while heating.
(ii) Petroleum is inflammable so extinguish all flames while working with it.
Experiment- 4th
Aim- To test the presence of adulterants in the given sample of sugar.
Theory-

11. Common adulterants of sugar are washing soda, chalk powder and semolina. Sugar is
soluble in water, so if any undissolved substance is left on dissolving sugar in water, then it
is indication of adulteration in it. Washing soda and chalk powder, both give effervescence
with dil. HCl. Hence their presence in the sugar sample can be detected by treating small
amount of sugar with dil. HCl.
Materials Required-
Test tube holder, dil. HCl & distilled water.
Procedure-
(i) Detection of Insoluble Impurities
Take small amount of sugar in a test tube and shake it with little water for 4-5 minutes.
Pure sugar dissolves in water but insoluble impurities do not dissolve.
(ii) Detection of Chalk Powder & Washing Soda
To small amount of sugar in a test tube, add few drops of dil. HCl. Brisk effervescence of
CO2 shows the presence of chalk powder or washing soda in the given sample of sugar.
Note- Powder the sugar before testing its solubility in water.
Experiment- 5th
Aim- To test the presence of adulterants in the given sample of red
chilli powder.
Theory-

12. Red chili powder is adulterated with either colours or brick powder. Brick powder, being heavy
than chilli powder, therefore, settles on bottom on dissolving it in a glass of in water. If colour has
been added to it, then water becomes coloured.
Materials Required-
One beaker, glass rod, water.
Procedure—
(i) Detection of Artificial Colours and Brick Powder
Take a glass beaker filled with water and pour a few grams of red chilli powder in it. Stir the
mixture with the glass rod and allow it to stand for a few minutes. Appearance of brick red
colour in water shows the presence of artificial colour in red chilli. If brick powder is used, it settles
down in the beaker.
Experiment- 6th
Aim- To test the presence of adulterants in the given sample of
turmeric powder.

13. Theory-
Yellow chalk powder & sawdust coloured with coaltar dye are the common adulterants
found in turmeric powder. Yellow chalk powder gives brisk effervescence with HCl whereas
coaltar dyes give violet colour with conc. HCl
Materials Required-
Test tube, holder, conc. HCl & water.
Procedure-
(i) Detection of Yellow Chalk Powder
Take about 0.5 g of turmeric powder in a test tube and add 1mL of dilute HCl. Evolution
of effervescence shows the presence of coloured chalk powder in turmeric.
2 HCl + CaCO3 --> CaCl2 + H2O + CO2
(ii) Detection of Sawdust Coloured with Coaltar Dye
Take about 1.0 g turmeric powder in a test tube add a few drops of conc. HCl. Instant
appearance of violet colour which persists on dilution with distilled water indicates the
presence of sawdust coloured with metanil yellow, a coaltar dye.
Experiment- 7th
Aim- To test the presence of adulterants in the given sample of pepper.

14. Theory-
The common adulterant in pepper is dried papaya seed.
Materials Required-
Beaker, water.
Procedure-
(i) Detection of Pappaya Seeds in Black Pepper
Take a beaker filled with distilled water and add one spoon full of
pepper. Papaya seeds float over water while pepper settles down.
Observations & Results:
S.N
o
FOOD PARTICLE COMMON
ADULTERANT
TEST

15. 1. Desi Ghee & Butter Vanspati ghee
starch & Potato
1. Add a little sugar & HCl to melt
sample of ghee or butter, shake
it for 5 minutes presence of pink
colour in aqueous layer indicate
vanaspati ghee.
2. Add 2 ml of water in ghee or
butter boil, add few drops of
iodine solution to it , appearance
of blue colour indicate the
presence of starch in the sample.
2. Mustard oil Argemone oil 5ml oil + conc. HNO3 orange/red
colour indicate the presence of
argemone oil.
3. Sugar Washing soda or
Chalk powder
Sample of sugar add dil. HCl – brisk
effervescence indicates presence of
washing soda or chalks powder.
4. Red chilli powder Brick powder or
dyes
Red chilli powder in a beaker +
distilled powder, Brick powder settle
down in the bottom, appearance of red
colour indicate the presence of dyes.
6. Pepper Dried papaya
seeds
Sample + water = dried papaya, seed
floats over the surface of water, pure
pepper settle down.
8. Turmeric powder Yellow chalk
powder.
Sample Turmeric powder + 2 ml HCl =
brisk effervescences indicate presence
of chalk powder.

16. Precautions
Conclusion
Selection of wholesome and no adulterated food is essential for daily life to make sure that
such foods do not cause any health hazard. It is not possible to ensure wholesome food only
on visual examination when the toxic contaminants are present in ppm level. However,
visual examination of the food before purchase makes sure to ensure absence of insects,
visual fungus, foreign matters, etc. Therefore, due care taken by the consumer at the time of
purchase of food after thoroughly examining can be of great help. Secondly, label
declaration on packed food is very important for knowing the ingredients and nutritional
value. It also helps in checking the freshness of the food and the period of best before use.
The consumer should avoid taking food from an unhygienic place and food being prepared
under unhygienic conditions. Such types of food may cause various diseases.
Consumption of cut fruits being sold in unhygienic conditions should be avoided. It is
always better to buy certified food from reputed shop.

17. Bibliography
 www.wikipedia.org
 www.icbse.com
 www.ncert.nic.in
 www.scribd.com
 APC Chemistry Lab Mannual for
Class-XII
Teacher’s Signature...............................
Remark....................................................

18. Chemistry
Project work
Adulteration
Supervised By- Presented By-
Mr. Pankaj Rai Vibhas Bhairav Singh
Chemistry Teacher Class- 12th A