Lipids Test

Question 1

General test for fats

Answer 1

Use of Sudan 3 solution
Black colour

Solubility of lipids

Question 2

Glycerol and glycerol containing lipids

Answer 2

Acrolein test (using KHSO4)
Irritating smell acrolein

Question 3

Test for unsaturation

Answer 3

Bromine or iodine water

Decolourization

Question 4

Libermann Burchard reaction (using acetic anhydride and chloroform)

Answer 4

Test for cholesterol

Green colour!!!!

Question 5

Salkowski reaction (using conc H2SO4)

Answer 5

Cholesterol test

Colour change

Question 6

Digitionin test (using digitionin)

Answer 6

Test for cholesterol

Precipitate formed

Question 7

Ninhydrin test (using ninhydrin reagent)

Answer 7

Test for amine containing lipids (phosphatidylethanolamine and phosphatidylserine)

Purple or violet colour - shows presence of ammonia

Question 8

What is saponification number ?

Answer 8

This is the number of mg of KOH required to saponify 1g of fat

Question 9

Saponification number varies _______ with _____?

Answer 9

Inversely

Chain length of fatty acids in the fats

Question 10

The longer the fatty acid, the smaller the saponification number

T or F

Answer 10

True

Question 11

What is Iodine number?

Answer 11

This is the number of gram of iodine needed to saturate 100g of fat

Question 12

What is the significance of iodine number?

Answer 12

It is a measure of unsaturation & it increases with more unsaturation.

Question 13

What is the significance of saponification number?

Answer 13

It is a measure of the chain length of the fatty acids in fats. Such that the more the saponification number, the shorter the fatty acid’s chain length.