Esters of long chain fatty acids and alcohol or closely related derivatives
LIPIDS
LIPIDS
1. fixed oils
2. fats
3. waxes
Functions
Structural Components
● Vitamins and Hormones
● Lipid Solubilization
● Energy Reserves
Properties
Insoluble in water
● Soluble in organic solvents
● Important features in cell membranes, fat soluble
● vitamins and steroid hormones
● Used as source of energy by animals
● Number of mg of Potassium hydroxide required to neutralize the free acids in 1g of the substance
Acid value or Acid number
Indicates the number of mg of Potassium hydroxide required to neutralize free acids and saponify the esters ● contained in 1g of the substance
Saponification value
Indicates the amount of free fatty acids present in the oil
Acid value or Acid number
Number of g of iodine absorbed under prescribed conditions by 100g of the substance
Iodine number
Indicates the degree of unsaturation
Iodine number
TESTS THAT DETERMINE THE IDENTITY, QUALITY & PURITY OF FIXED OILS
Acid value or Acid number
Saponification value
Iodine number
Melting Point
Specific Gravity
Refractive Index
CH3 (CH2 )10 CO2H
Lauric Acid
CH3 (CH2 )12 CO2H
Myristic Acid
CH3 (CH2 )14 CO2H
Palmitic Acid
CH3 (CH2 )16 CO2H
Stearic Acid
CH3 (CH2 )18 CO2H
Arachidonic
Melting Point
Lauric Acid
45 oC
Myristic Acid
55 oC
Palmitic Acid
63 oC
Stearic Acid
69 oC
Arachidonic
76 oC