Food Analysis

1. ASSIGNMENT ON
DIFFERENT METHODS OF FOOD ADULTERATION
Subject Name: Food Analysis (FA)
Submitted To: Dr. Chenna Kesava Reddy
(Assistant Professor)
Submitted By: Panpatte Suraj Ashok
02PGDM-FPBM17

2. DIFFERENT METHODS OF FOOD ADULTERATION
INTRODUCTION:
• Food Adulteration refers to the process by which the quality or the nature of a given food
is reduced through addition of adulterants or removal of vital substance.
• Food adulterants refer to the foreign and usually inferior chemical substance present in
food that cause harm or is unwanted in the food.
• Basically, during food adulteration, small quantities of non-nutritious substances are
added intentionally to improve the appearance, texture or storage properties of the food.
• Food adulteration is quite common in the developing countries.
FOOD IS ADULTERATED IF:
• The food sold does not meet the nature of the substance or quality as per the demand of
consumer.
• The food contains inferior or cheaper substance
• The food has been prepared, packed or kept under unclean conditions leading to
contamination.
• Food contains substances that depreciates or injuriously affects the health.
• If the food’s original nature is substituted wholly or partially by abstracting a portion of
vital substance from food.
• If it is an imitation of some other food substance.
CAUSES OF FOOD ADULTERATION:
• Profit motive of traders: Done as a part of the business strategy
• Food insecurity: To increase quantity of food production and sales.
• Increased Urbanization: To make maximum profit from food items by fewer investments.
• High population demands: Increased food demand of the population and its changing
trends.
• Illiteracy of general public: Lack of consciousness of proper food consumption.
• Lack of effective food laws
• Lack of government in initiative
TYPES OF FOOD ADULTERATION:
1. Intentional adulteration: The adulterants are added as a deliberate act with intention to
increase profit. E.G. sand, marble chips, stones, chalk powder, etc.

3. 2. Incidental Adulteration: Adulterants are found in food due to negligence, ignorance or
lack of proper facilities. E.G. Packaging hazards like larvae of insects, droppings,
pesticide residues, etc.
3. Metallic adulteration: When the metallic substances are added intentionally or
accidentally. Eg: arsenic, pesticides, lead from water, mercury from effluents, tins from
cans, etc.
METHODS OF FOOD ADULTERATION:
1. Mixing: Mixing of clay, stones, pebbles, sand, marble chips, etc.
2. Substitution: Cheaper and inferior substances being replaced wholly or partially with
good ones.
3. Concealing quality: Trying to hide the food standard. E.G. adding captions of qualitative
food to low quality for selling.
4. Decomposed food: Mainly in fruits and vegetables. The decomposed ones are mixed
with good ones
5. Misbranding/ False labels: Includes duplicate food stuffs, changing of manufacture and
expiry dates.
6. Addition of toxicants: adding non-edible substances like argemone in mustard oil, low
quality preservatives, colouring agents, etc.
FOOD ADULTERATION IN DEVELOPING COUNTRIES:

4. • Fresh vegetables and fruits, the main part of our meal is adulterated by the self applied
fertilizers and pesticides by the farmers to increase the production and to avoid the
attacks of insects and diseases.
• Wax coating/ dipping in chemical water like copper sulphate (CuSO4) is used for
increasing the marketing by making them attractive and fresh looking.
• Nowadays, vegetables producing fields are irrigated with sewerage water which included
detergents, human faeces, factory wastes having high concentrations of toxic heavy
metals i.e. lead and arsenic which can cause damage to liver, kidney and cancer.
• Vegetables and fruits are also openly sold at roads which cause the free fallen smoke and
dust particles resulting in contamination.
• Screen is used as sweetening agent in many confectionary products, instead of sucrose,
which is harmful for health
• The storage room are cleaned and fumigated to protect the storage products from insects
which contain hazardous substances affecting the health.
• Brick dust is added in chili powder on the other hand lead chromate and metanil yellow is
added in turmeric powder that deteriorates health condition.
• Sugar and salt is adulterated with calcium carbonate, similarly urea is mixed in parched
rice.
• The saw dust is added in coriander powder and cumin powder.
• The sodium bicarbonate in jiggery, coal tar dye in tea leaves, metanil yellow colour in
gram powder.
Detection of common adulterants in food:
1. Detection from Milk:
There are many methods known for detection of adulteration in milk but the methods discussed
below are simple but rapid and sensitive methods to detect adulteration.
 Common Types of Adulterants in milk
➢ Neutralizers
➢ Starch
➢ Formalin
➢ Glucose
➢ Cane sugar
➢ Urea
➢ Water
Detection of Neutralizers in milk
• Take 5 ml of milk in a test tube & add 5 ml alcohol followed by 4-5 drops of rosalic acid.
• If the color of milk changes to pinkish red, then it is inferred that the milk is adulterated
with sodium carbonate / sodium bicarbonate and hence unfit for human consumption.

5. Test for detection of formalin
• Take 10 ml of milk in test tube
• Add 5 ml of conc. sulphuric acid on the sides of the test tube without shaking.
• If a violet or blue ring appears at the intersection of the two layers, then it shows the
presence of formalin.
Test for detection of urea
• Five ml of milk is mixed well with 5 ml Para dimethyl amino benzaldehyde (16%). If the
solution turns yellow in color, then the given sample of milk is added with urea.
• Take 5 ml of milk in a test tube Add 0.2 ml of urease (20 mg / ml). Shake well at room
temperature. Then add 0.1 ml of bromothymol blue solution (0.5%) Appearance of blue
color after 10-15 min indicates the adulteration milk with urea
2. Detection from Sweeting agent
A) Sugar:
i. Chalk powder:
• Dissolve 10 gm of sample in a glass of water, allow settling, Chalk will settle down at the
bottom.
ii. Urea:
• On dissolving in water it gives a smell of ammonia.
B) Honey:
 Sugar solution:
• A cotton wick dipped in pure honey when lighted with a match stick burns and shows
the purity of honey. If adulterated, the presence of water will not allow the honey to
burn, If it does; it will produce a cracking sound.
• This test is only for added water.
3. Detection from Oil and Fats:
A) Ghee:
Vanaspathy or Margarine:
• 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.

6. Shake for one minute and let it for five minutes. Appearance of crimson colour in
lower (acid) of Vanaspati or Margarine.
• The test specific seasame which is for oil compulsorily added is to Vanaspati and
Mrgarine. Some coal tar colours also give a positive test. If the test is positive i.e. red
colour develops only adding strong by 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.
ii. Mashed 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.
2. Butter:
Vanaspati or Margarine:
• 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 color 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 color also gives a positive test.
• If the test is positive i.e. red color develops only by adding strong Hydrochloric acid
(without adding crystals of j sugar) then the sample is adulterated with coal tar dye. If
the crimson or red color develops after adding and shaking with sugar, then alone
Vanaspati or Margarine is present
Mashed potatoes other starches:
• The presence of mashed potatoes and sweet potatoes in a sample of butter can easily
detected by adding a few drops of iodine (which is brownish in colour), turns to blue.
3. Edible oil:
Prohibited color:
• 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. Color will separate in the upper layer of the
solution.
4. Detection from Food Grain and their Products:
A. Wheat, Rice, Maize, Jawar, Bajra, chana, Barley etc.:

7. Dust, pebble, stone, straw, weed seeds, damaged grain, weevilled grain, insects,
rodent hair and excreta:
• These may be examined visually to see foreign matter, damaged grains, discolored
grains, insects, rodent contamination etc.
• Damaged / discolored grains should be as low as possible since they may be affected by
fungal toxins, argemone seeds, Dhatura seeds etc. In moderately excessive amount can
result in risk to health, Discard the damaged undesirable grains before use
B. Maida:
Resultant atta or cheap flour:
• When dough is prepared from resultant or left out atta, more water has to be used. The
normal taste of chapattis prepared out of wheat is somewhat sweetish whereas those
prepared out of adulterated wheat will taste insipid.
C. Maida/ Rice:
Boric Acid:
• Take a small amount of sample in a test tube, add some water and shake. Add a few drops
of HCl. Dip a turmeric paper strip if it turns red, boric acid is present.
D. Wheat barja and other grains:
Ergot (a fungus containing poisonous substance):
• Purple black longer sized grains in Bajra show the presence of Ergots,
• Put some grains In a glass tumbler containing 20 per cent salt solution (20 gm common
salt to 100 ml water) purple black longer size grain Ergot floats over the surface while
sound grains settle down.
E. Dhatura:
• Dhatura seeds are flat with edges with blackish brown color which can be separated out
by close examination.
F. Karnel Bunt:
• The affected wheat kernel have a dull appearance, blackish in color and rotten fish smell,
5. Detection from Spices:
• 1. Whole spices:

8. Dirt, dust, straw, insect, damaged seeds, other seeds, rodent hair and excrete
• These can be examined visually
2. Black pepper:
Papaya seeds:
• Papaya seeds can be separated out from pepper as they are shrunken, oval in shape and
greenish brown or brownish black in color.
Light black Pepper:
• Float the sample of black pepper in alcohol (rectified spirit). The black pepper berries
sink while the papaya seeds and light black pepper float.
• Press the berries with the help of fingers light peppers will break easily while black
berries of pepper will not break.
Coated with mineral oil:
• Black pepper coated with mineral oil gives Kerosene like smell.
3. Cloves:
Volatile oil extracted (exhausted cloves):
• Exhausted cloves can be identified by its small size and shrunken appearance. The
characteristic pungent of genuine cloves is less pronounced in exhausted cloves
Coated with mineral oil:
• Cloves coated with mineral oil gives kerosene like smell
4. Mustard seed:
Argemone seed:
• Mustard seeds have a smooth surface. The argemone seed have grainy and rough surface
and are black and hence can be separated out by close examination. When Mustard seed
is pressed inside it is yellow while for Argemone seed it is white.
• Use magnifying glass for identification.
5. Powered spices:
Added starch:

9. • Add a few drops of tincture of Iodine or Iodine solution. Indication of blue colour shows
the presence of starch.
• Iodine test for added starch is not applicable for turmeric powder.
Common Salt:
• Taste for addition of common salt.
6. Turmeric Powder:
Colored saw dust:
• Take a tea spoon full of turmeric powder in a test tube. Add a few drops of concentrated
Hydrochloric acid. Instant appearance of pink colour which disappears on dilution with
water shows the presence of turmeric. If the colour persists, metanil yellow (an artificial
colour) a not permitted coal tar colour is present.
• This test is only for Metanil yellow.
7. Turmeric whole:
Lead chromate:
• Appears to be bright in colour which leaves colour immediately in water.
Chalk Powder or yellow soapstone powder:
• Take a small quantity of turmeric powder in a test tube containing small quantity of
water. Add a few drops of concentrated Hydrochloric acid, effervescence (give off
bubbles) will indicate the presence of chalk or yellow soap stone powder.
8. Chilies powder:
Brick powder, salt powder or talc, powder:
• Take a tea spoon full of chillies powder in a glass of water. Coloured water extract will
show the presence of artificial color.
• Any grittiness that may be felt on rubbing the sediment at the bottom of glass confirms
the presence of brick powder/sand, soapy and smooth touch of the white residue at the
bottom indicates the presence of soap stone.
• To a little powder of chilli add small amount of conc. HC1 and mix to the consistency of
paste, dip the rear end of the match stick into the paste and hold over the flame, brick red
flame color due to the presence of calcium slats in brick powder.
• This test is only for earthy material
HEALTH HAZARDS OF FOOD ADULTERATION:

10. Some health hazards associated with specific food adulteration incudes;
• Mineral oil if added to edible oil and fats can cause cancers.
• Lead chromate when added to turmeric powder and spices can cause anaemia, paralysis,
brain damage and abortions.
• Lead added to water, natural and processed food can lead to lead poisoning, foot drop,
insomnia, constipation, anaemia, and mental retardation.
• Cobalt added to water and liquors and can cause cardiac damage also copper, tin, and
zinc can cause colics, vomiting and diarrhoea.
• Mercury in mercury fungicide treated grains, or mercury-contaminated fish can cause
brain damage, paralysis, and death.
• Non-permitted color or permitted food color like metal yellow, beyond the safe limit in
colored food can cause allergies, hyperactivity, liver damage, infertility, anaemia, cancer
and birth defects.