This document provides information about fats, oils, and their properties. It defines fats and oils as lipids that are saponifiable (containing ester groups) and made up of triglycerides consisting of glycerol bonded to three fatty acid chains. The document discusses the hydrolysis, hydrogenation, saponification, and rancidification reactions of fats and oils. It also defines analytical values used to characterize fats and oils such as saponification value, iodine value, and acid value. Sources and extraction methods of fats and oils from plants and animals are also summarized.

1. Fats and Oils
Mr. P.S.Kore
Assistant Professor(Research Scholar)
Department of Pharmaceutical Chemistry
RCP, Kasegaon.

2. Contents
o FATTY ACIDS: REACTIONS.
o HYDROLYSIS
o HYDROGENATION
o SAPONIFICATION
o RANCIDITY OF OILS
o DRYING OF OILS
o ANALYTICAL CONSTANTS:
o ACID VALUE
o SAPONIFICATION VALUE
o ESTER VALUE
o IODINE VALUE
o ACETYL VALUE
o REICHERT MEISSL (RM) VALUE

3. Fats And Oils
o A lipid can be defined as naturally and chemically occurring
substance that is insoluble in water and soluble in alcohol, ether,
and chloroform.
o The types of lipids involved include Bile salts, Eiosanoids,
Glycolipids, Ketone bodies, Phospholipids, Sphingolipids, Steroids
and Cholesterols.
o Lipids are fats that are either absorbed from blood or synthesized
by the liver.
o Triglycerides and cholesterol contribute most of diseases.
o Waxes: Waxes are esters of long-chain fatty acids and long chain
monohydric alcohols, each containing 16 to 34 carbon atoms.

4.  They are produced from plants and animals, also melts between
350C-1000C.
 It is insoluble in water but soluble in organic solvents like.
 Various types of waxes:
 1. Bees wax: obtained from honeycomb of the bee.
 It melts at 620C-650C and used for boot polishes, cosmetic creams,
lipsticks, floor and furniture polishes and candles.
 2. Carnauba Wax: derived from leaves of carnauba palm native in
brazil, melts at 80-870 C and used for boot polishes, coating on
mimeograph stencils and carbon papers.
 3.Supermaceti Wax: obtained from head-cavity of the sperm
whale, melts at 42-500C and is primarily used in emollient(skin
southner) in ointments and cosmetics. Also used in laundry wax
for lustering linen, making soap and candles.
 All lipids are hydrophobic and mostly insoluble in blood, so they
require transport within hydrophilic spherical structures called
lipoproteins.

5. Fats And Oils
o Fats and oils are lipids which are saponifiable(having ester
functional group)(i.e.complex lipids), while other such steroids
are non-saponifiable.
o Natural fats and oils are triesters of glycerol with long chain
carboxylic acids (12 to 20 carbons).
o They are known as Triglycerides.
C
H2
C
H
C
H2
OH
OH
OH
+
C R
O
O
H
C R
O
O
H
C R
O
O
H
C
H2
C
H
C
H2
O
O
O
C
C
C
R
R
R
O
O
O
+ 3H2O
GLYCEROL CARBOXYLIC ACID A TRIGLYCERIDE

6. Fats And Oils
o Ester: The chemical linkage that holds an alcohol group
(OH) and an acid group (such as COOH) together. An
ester bond is the connection between a fatty acid and
glycerol in glycerides.
o Glycerol: A three carbon chain, with each carbon
containing an alcohol group. One, two or three fatty
acids , may be attached to glycerol to give a mono, di or
triglyceride.
o Triglyceride: Three fatty acids attached to a glycerol
molecule. If the three fatty acids are the same, it is a
simple triglyceride, if they are different from each
other, it is a mixed triglyceride.

7. Fats And Oils
o When three OH groups of glycerol are esterified with the same
acid, the triester is known as simple glyceride, where as if two or
more different acids called as mixed glyceride.
C
H2
C
H
C
H2
O
O
O
C
C
C
(CH2)14 CH3
(CH2)14 CH3
(CH2)14 CH3
O
O
O
GLYCERYL TRIPALMITATE
(a smiple glyceride)
C
H2
C
H
C
H2
O
O
O
C
C
C
(CH2)14 CH3
(CH2)16 CH3
(CH2)7CH=CH=CH(CH 2)7CH3
O
O
O
GLYCERYL PALMITOSTEAROOLEATE
(a mixed glyceride)

8. Differences
Fats Oils
 1. Remains solid at room
temperature. (due to large %
of saturated fatty acid)
 2.Relatively more saturated
 3. High melting point.(above
200C)
 4. More stable.
 5. Source: Mainly animals.
 6. No double bonds.
 7. Vander waal’s forces
between molecules are
stronger.
 1. Remains liquid at room
temperature. (due to large %
of unsaturated fatty acid)
 2.Relatively more unsaturated
 3. Low melting point. (below
200C)
 4. Less stable.
 5. Source: Mainly Plants.
 6. Have double bonds.
 7. Vander waal’s forces
between molecules are
weaker.

9. Occurrence and extraction
 Plants : Plants are store large quantities of fats in their seeds,
roots and fruits. Castor beans, peanuts, coconuts and olives
have a high fat content.
 In animals: in animals, the fat deposits are to be found
mostly under the skin and around the intestine and
kidneys.
 Extraction:
 1. Rendering: The animal tissues containing the fat are
chopped off and heated dry or with water until the fat
melts and can be removed.
 2. Pressing: oil are obtained from seeds by crushing
between steel rollers and then pressed in a hydraulic
press.
 3. Solvent extraction: It is applied to the residue after
pressing and rendering for complete removal of oil or fat.
Solvents used are petroleum ether and benzene.

10. Physical and Chemical properties
 Fats and oils are solid or liquid having a greasy feel, but
when pure it is colorless, odorless and tasteless.
 They are insoluble in water but soluble in organic solvents
like ether, chloroform, benzene, etc.
 They have a lower specific gravity than water and
consequently float on surface when mixed with each other.
 They form emulsion when agitated with water in presence
of soap or gelatin.

11. Physical and Chemical properties
Fat and oils are triesters of glycerol with saturated
and unsaturated fatty acids. Their reactions are those
of ester group in triplicate and carbon-carbon double
bonds.
1. Hydrolysis
2. Hydrogenation.
3. Hydrogenolysis
4. Rancidification
5. Drying

12. Physical and Chemical properties
1. Hydrolysis: They are hydrolysed by heating with
acids or alkalies or superheated steam.
When boiled with sodium or potassium
hydroxide solution, the products are sodium or
potassium salts. They latter are called as soap and
alkaline hydrolysis are called as saponification.
C
H2
C
H
C
H2
O
O
O
C
C
C
R
R'
R''
O
O
O
+ 3NaOH
A TRIGLYCERIDE
C
H2
C
H
C
H2
OH
OH
OH
+
C R
O
Na+-O
C R
O
Na
+
O
-
C R
O
Na
+
O
-
GLYCEROL Soap

13. Physical and Chemical properties
2. Hydrogenation: Vegetable oils are triglycerides of
unsaturated fatty acids such as oleic acid and linolec
acid. On catalytic hydrogenation at low pressure,
hydrogen adds across the carbon-carbon double bond
of the acid components of the triglycerides, which results
in formation of saturated triglycerides. This process is
called as Hardening
GLYCERYL TRIOLEATE
OH2C C(CH2)7CH=CH(CH 2)CH3
O
C
H C(CH2)7CH=CH(CH 2)CH3
O
CH2OC(CH2)7CH=CH(CH 2)CH3
O
+3H2
Heat
OH2C C(CH2)16CH 3
O
C
H C(CH2)16CH 3
O
CH2OC(CH2)16CH 3
O
Glyceryl triestearate (solid fat)
M.P
-
17
0
LIQUID FAT
M.P.- 55
0
c

14. Physical and Chemical properties
3. Hydrogenolysis: Vlike a ester, the ester group of
triglycerides (fats and oils) can be reduced with hydrogen
in the presence of copper chromite catalyst, CuCr2O4, at
high temperature. This reaction called
hydrogenolysis(hydrogenation involving cleavage) gives
in addition glycerol and long chain primary alcohol.
GLYCERYL TRIOLAURATE
C
H3
C
H3
C
H3 (CH2)10 C
O
O CH2
(CH2)10 C
O
O CH
(CH2)10 C
O
O CH2
+6H2
Heat
3CH3(CH2)10 CH2OH
CuCr2O4
+
C
H2
C
H
CH2
OH
OH
OH
LARURYL ALCOHOL
GLYCEROL

15. Physical and Chemical properties
4. Rancidification: When fats and oils are left exposed to
moist air, they develop foul smell and sour taste. They are
said to have become rancid. Rancidification is caused by
two types of reactions:
A. Oxidation: it occurs due to the oxidation of carbon-
carbon double bonds in fats and oils to produce volatile
carboxylic acids.
B. Hydrolysis: it involves the hydrolysis of one or more
ester linkage in fats and oils to produce the original
acid.
Bacteria from the air furnish enzymes to promote such
reactions. So antioxidants are added to many edible oil
to prevent rancidification.

16. Physical and Chemical properties
5. Drying: When highly unsaturated fats and oils are
exposed to air, they undergo oxidation and
polymerization to form a thin waterproof film, such oils
are called as Drying Oils and the reaction is referred as
drying.
Linseed oil, which is rich in linolenic acid is a common
drying oil used in oil-based paints. Non-drying are the
either saturated or only moderately unsaturated.

17. Saponification Value
 Saponification value is also called as saponification
number.
 It determines the approximate molecular weight of a fat
or oil.
 Def: Saponification number is defined as the number of
miligrams of KOH required to saponify one gram of fat or
oil.
 In saponification one mole of fat or oil react with three
moles of KOH since the former has ester groups.
 If M be the molecular weight of fat, M grams of it require
3*56=168 grams or 168,000 miligrams of KOH for
saponification.
 Saponification number of fat= 168000/M

18. Saponification Value
 As per expression the saponification value of a fat is
inversely proportional to the molecular weight.
 A lower value of sap, therefore shows the preponderance
of high molecular weight fatty acid residues.
 On other hand high value of sap indicates preponderance
of low molecular weight of fatty acids.