To Study Common Adulterants In Sugar, Turmeric Powder, Chili Powder and

Pepper

(A) TO TEST THE PRESENCE OF ADULTERANT IN GIVEN SAMPLE OF SUGAR.

Theory:

Common adulterants of sugar are 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 adulterant in it. Chalk

powder given effervescence with dil. HCL,

Hence its presence in the sugar sample can

be detecte3d by treating small amount of

sugar with dil. HCL.

Apparatus and Chemicals:

Test tubes and test tube stand dilute hydrochloric acid and distilled water.

Procedure:

a) Take about two grams of the sugar sample in a test tube and add

about 10ml of water into it. Shake the tube for about 5 minutes.

Presence of undissolved substance indicates adulteration in the sugar.

b) Take about two grams of the sugar sample in a clean and dry test

tube. Add to it about 5ml of dilute hydrochloric acid. Effervescence an

addition of acid indicates the presence of chalk powder in the sugar.

(B) TO FIND OUT ADULTERATION IN GIVEN SAMPLE OF CHILLI POWDER.

Theory:

Red chili powder is adulterated with

either coloured powder of bricks. Brick

powder being heavy than chili powder,

settles at the bottom on dissolving it in a

glass of water. If colour is added to the

chili powder, then water will become

coloured.

Apparatus and Chemicals:

One glass or beaker, a glass rod and water.

Procedure:

Add small amount of the given chili powder in a glass full of water. Stir the

contents with a glass rod for a minute and wait for 2-3 minutes. Setting of

brick powder at bottom and appearance of red colour indicates adulteration

in the given sample.

(C) TO FIND OUT THE ADULTERATION IN GIVEN SAMPLE OF TRUMERIC POWDER.

Theory:

Yellow chalk powder, a common adulterant, of the turmeric powder gives effervescence with dilute hydrochloric acid.

Apparatus and Chemicals:

Test tubes and test tube stand dilute hydrochloric acid and water.

Procedure:

a) Take about 100g of the powdered sample ion a test tube and add to it about 10ml of dilute hydrochloric acid. Effervescence indicates the presence of chalk powder in the sample.

b) Dilute the contents of the tube with 30-40ml of water. Disappearance

of the violet colour formed previously indicates the purity of turmeric

powder. B if violet first formed with dil. HCL persists, and then it is

contaminated with yellow dye.

(D) TO FIND THE ADULTERATION IN THE GIVEN SAMPLE OF PEPPER.

Apparatus and Chemicals:

Test tubes, test tube stand, pepper powder etc.

Procedure:

Add a small amount of the given sample

in a test tube and fill it with water. Dried

papaya seeds will floatation on the

surface of water while the pure pepper

will settle down at the bottom of the test tube.

Precautions:

1. Petroleum is inflammable liquid. So, while performing experiment with

it, it may be extinguish all the flames.

2. Always hold the test tube with a test tube holder because oil catches

fire easily.

(E) TO FIND THE ADULTERATION IN THE GIVEN SAMPLE OF GHEE.

1. Butyrorefractometer reading (BR Value)

Properly filtered ghee whose reading temperature is around 40oC is taken; 2-

3 drops of it is poured in to the Butyrorefractometer by the side of the glass

rod. Now, the reading is noted by the scale placed above the meter. Care has

to be exercised to maintain the temperature of water that is flowing over the

thermometer to be at 40oC. If the temperature deviates, then the results

obtained may not be accurate. The normal BR value of ghee ranges between

40 and 43.

2. Baudoin Test (Detection of adulteration of ghee with vanaspathi or hydrogenated vegetable oil)

As per the prevention of food adulteration act, it has been made mandatory

to add 5% sesame oil o vanaspathi in order to detect the presence of

vanaspathi in ghee through Baudoin test. The principle behind the test is

development of permanent crimson red colour with furfural in the presence

of concentrated hydrochloric acid in ghee adulterated with vanaspathi.

How to Detect?

Take 5g of molten filtered ghee in a test tube and add 5ml of concentrated

HCL acid and 0.1ml of furfural solution in alcohol (2%) and mix the contents

thoroughly and it is allowed to remain undisturbed for 10 min. development

of crimson red colour shows that the ghee is adulterated with vanaspathi.

3. Detection of mineral oil in ghee.

About 2g of ghee is saponified with 25ml of 50% alcoholic potassium

hydroxide for one hour. Then the saponified content is transferred to a

beaker containing 100 ml of water. Development of turbidity indicates the

adulteration of mineral oil in ghee.