By students of Sir Dr. M.S. GOSAVI COLLEGE OF PHARMACEUTICAL EDUCATION AND RESEARCH, NASHIK.

1. FATS AND OILS
CONTINUOUS ASSESSMENT-01
GROUP NO-13

2. 97
98
100
99
101
102
103
104
DHANASHREE SANDHAN
AVNI SHARMA
PRERNA SAWALE
SHRADDHA SHIMPI
VAISHALI SAVANT
PRATIK SHENDE
SAKSHI SHIRSATH
RENUKA SAWANT

3. • INTRODUCTION
• NOMENCLATURE
• HYDROLYSIS
• HYDROGENATION
• HYDROGENOLYSIS
• SAPONIFICATION
• RANCIDIFICATION
• DRYING OILS
• ACID VALUE
• SAPONIFICATION VALUE
• ESTER VALUE
• IODINE VALUE
• ACETYL VALUE
• REICHERT MEISSL VALUE
Various chemical reactions of fats and oils
Analysis of fats and oils

4.  Fats and oils are major part of lipid present in adipose tissue of mammals.
 Fats and oil are made up of molecules known as triglycerides. Which are the esters of three fatty acid chains and the alcohol , glycerol.
 If the glycerol is esterifies at all –OH sites by some fatty acid (i.e.R1,R2,R3) attach with carboxylic acid ( basically from 12-20 carbons) , the
resulting ester is called triglyceride.
 A triglyceride existing in solid state at 25ᵒC is called fats while that exists in liquid state at 25 degree celcius is called oils.
 Naturally occurring fats and oils are complex mixture of mixed triglyceride. Fats contain triglyceride with long and saturated fatty
acid chains and usually obtained from animal sources.
 Oils contain triglyceride with a short and unsaturated fatty acid chain and usually obtain from plant origin .
 Examples- lard(pig fat), tallow(beef), coconut oil, castor oil, olive oil, soyabean oil etc.
 A crude fat along with glyceryl ester contains some amount of free fatty acids and 1-2% of unsaponifiable matter like sterols.

5. PHYSICAL PROPERTIES -

6. • A fat is product of fatty acid and bonded to a backbone structure, which is often a glycerol which consists of
a three carbon chain.
• A triglyceride is specific type of fat formed by combination of three fatty acids with a glycerol backbone.
• The nomenclature of fatty acid is confusing with many different names being used for identical substance.
• A fatty acid is unsaturated if there is atleast one double bond between the carbon atoms in the fatty acid.
• A fatty acid with only one double bond is called monounsaturated fatty acid.
• A fatty acid with two or more double bond is called polyunsaturated fatty acid.
• A fatty acid with no double bond between carbon atom in the main carbon chain of fatty acid is called
saturated fatty acid.
• The term ‘omega’ refers to position of double bond in relation to methyl group on end of fatty acid.
• Trans fatty acid are unsaturated fatty acid with unsaturated bond between carbon atoms of fatty acid
arranged in trans configuration instead of more common cis configuration.

7. • For saturated fatty acid suffix ‘anoic acid’ is used.
• For unsaturated fatty acid suffix ‘enoic acid’ is used.

8. o Sodium hydroxide causes hydrolysis of fats and it results in the cleavage of ester linkage of fats
to give glycerol and sodium salt of long chain fatty acid known as soaps.
o It can also be done by heating fat with water under pressure.
o Common soaps are the mixtures of sodium salts of ‘C’ atoms (12 atoms)and higher fatty acids.
o Soap molecules have both lipophilic (lipid loving) and hydrophilic (water loving )groups.
o The lipophilic group dissolve oils while hydrophilic portion dissolves water.
o Soap molecules on dissolution in water forms micelles.
o Hydrolysis reaction can be done by 3 ways-
BY WATER BY ENZYMES BY ACIDS

9. • By water- Fat undergoes hydrolysis in presence of water at 443K and 6 to 8 atm pressure .Zinc oxide is used as catalyst.
• By enzyme- It can be done by adding enzyme lipase to an emulsion of fat in water.
• By acids- Mineral acids causes hydrolysis of fats. For this mixture of sulphonic acids which are obtained by sulphonation
of mixture of oleic acid and benzene.
• The above three ways gives glycerol and fatty acid as a product of hydrolysis of fats while alkaline hydrolysis of fatsgives
glycerol and soap which are used as cleansing agent.

10. • Oils have large amount of unsaturated portion in the form of glycerides.
• When hydrogen is passed through oils under pressure and by using catalyst at high temperature oils gets converted into
solid fats.It is also known as hardening of oils.
• Hydrogenation is effectively done by adding small amount of finely divided Nickel or Raney nickel as a catalyst.
• By hydrogenation, unsaturated acid part of oil get reduced into saturated part and hence liquid oil get converted into
semi solid fat.
• In actual, hydrogenation is not carried out completely but is stopped as fat of desired consistency and viscosity is
obtained.The fats looks like ghee in appearance and is known as vanaspati ghee.
• Fully hydrogenated fats are very hard and cannot be digested easily in intestine.
• It also involves various complicated problems like isomerization, selective reduction, etc and these problems can be
overcome by arresting the reaction before all unsaturated fats get completely saturated with hydrogen.

11. • This is an cleavage reaction in which
fat and oil molecule is treated with
excess of hydrogen under pressure in
presence of Copper-Chromium
catalyst.
•This reaction gives glycerol and long
chain primary alcohol.
• Sometimes, active hydrogen can be
obtained by action of metallic sodium
with a water insoluble alcohol like 2-
hexanol.

12. • It is a reaction in which triglyceride is hydrolyzed with a strong
base like NaOH to form soap.
• Saponification is a process in which a soap and salts are obtained
from triglyceride in presence of NaOH.
• If NaOH is used for hydrolysis hard soap are obtained from
saturated fats.
• While, If KOH is used for hydrolysis soft soap are obtained from
unsaturated fats/oils.

14. On long storage and in contact with air, moisture and sunlight , oils
and fats undergo decomposition and starts smelling unpleasant.
This process is known as rancidification.
Oil is said to be rancid oil.
Rancidity occurs by following causes:
1)Oxidation of unsaturated acids
2)Enzymatic hydrolysis
3)Beta oxidation of saturated fatty acids

15. 1)Oxidation of unsaturated acids-
In presence of light and moisture
Small amount of unsaturated acid present in fats/oils
get oxidised by air
Form peroxides and further breakdown into aldehydes having
unpleasant smell and taste
 Saturated fatty acids do not get rancid.
 It can be checked by adding small quantity
of phenolic substances which act as antioxidants.

16. 2)Enzymatic hydrolysis-
Due to presence of microorganisms
Fats get hydrolysed by enzymes called lipases
Produce fatty acids having sour taste and
unpleasant odour
Example : Butter gets rancid due to production of
butyric acid.

17. 3)Beta oxidation of saturated fatty acids-
 Fats having saturated fatty acids undergo ketone rancidity.
 Saturated acids undergo beta oxidation to form keto acids which gives
carbon dioxide to form ketones having pungent unpleasant odour.

18. • Some glycerides of unsaturated acids having two or more double bonds absorb
oxygen from air and get polymerised to form hard transparent coating which is
used in making paints and oil cloth.
• This phenomenon is called drying and oils as drying oils.
• For example: Linseed oil, Tung oil, Perilla are drying oil
• If given acid contains conjugate system of double bonds then drying takes
place much more rapidly as compared to fats containing non conjugated double
bonds.
• It involves addition of oxygen to unsaturated bonds and causes some amount
of polymerisation.
• Drying can be achieved faster by addition of driers like salts of manganese, lead,
Cobalt salts of short chain acids, etc
• Oils, depending on their exposure to light and air can be classified as

19. A)Non-Drying oils-
On exposure to light and long storage gets rancid.
It mostly consists of triolein.
Gets decomposed into glycerol and fatty acids (saturated and non saturated).
Unsaturated acids get oxidised into aldehyes and acids with lesser carbon atoms in the
molecule.
Saturated acids get decomposed by enzymes to form ketones. For example, olive oil and
almond oil.
B) Drying oils-
They are either natural or symmetric saturated fatty acids.
They form a solid elastic film.
A good drying oil dries within 4-5 hours.
For example: Linseed oil, walnut oil, poppyseed oil, perilla oil, etc

20. C)Semi- drying oils-
Have high level of linoleic acid and low content of linolenic acid as compared to non- drying oils.
●For example: Sunflower oil, cotton seed oil, etc
➢Drying oils are used as medium for paints, varnishes and lacquers.
➢Paints are suspended along of some pigments or organic colouring matter in linseed oil to
which some turpentine oil has been added as thinner.
➢These paints when applied on wooden surface , they qiuckly dry up forming a tough organic
film which protects surface.

21. • Definition-
The acid value is defined as the number
of milligrams of potassium hydroxide
required to neutralize the free fatty acids
present in one gram of fat .It is a relative
measure of rancidity as free fatty acid are
normally formed during decomposition of oil
glycerides. The value is also expressed as
percent of free fatty acids calculated as oleic
acid.
• Principle-
The acid value is determined by directly
titrating the oil/fats in an alcoholic medium
against standard potassium hydroxide /sodium
hydroxide solution.

22. • The value is a measure of the amount of fatty acid which have been liberated by hydrolysis from the glycerides due to the
action of moisture , temperature and/or lipolytic enzyme lipase.
• Acid value is defined as the no. of mg KOH required to neutralized the free fatty acids in one gram of fats or oil.
• The STD for edible fats and oil indicate that the acid value must not exceed 0.6 mg KOH/1gm.
• Method-
1)Weigh 10gm of sample.
2)Dissolve in sample in 50 mi equal volume of ethanol and ether.
3)Titrate the mixture using 0.1M NAOH/KOH solution with pH as indicator.
• ACID VALUE =56.1* V KOH /W
Where, V KOH: volume of potassium hydroxide (mL)
W: weight of fats or oil being examined (gm)
• Result-
High acid value indicates that given sample of fats and oils is of low quantity and stored under improper conditions.

23. •Definition-
The saponification value is the number of mg of potassium hydroxide required to
saponify 1 gram of oil/fats.
•Analytical importance-
The saponification value is saponified by refluxing with a known excess
of alcoholic potassium hydroxide solution. Alkali required for
saponification is determind by titration of the excess potassium hydroxide
with standard HCL.

24. • The Saponification value in an index of mean molecular weight of the fatty acid of glycerides
comprising a fat. Lower the saponification value larger the molecular weight of fatty acid in the
glycerides and vice versa.
• Method-
1) Weigh 2 gram of oil into glass flask.
2) Add 25ml of alcoholic KOH sol and boil for 1 hour under a condenser shaking the content of the
flask at frequent interval.
3) Determine the access of alkali by titration with HCL using 0.5ml of indicator as phenolphthalein.
4) Set a blank test upon the same quantity of KOH at the same time and under the same condition.
5) SAPONIFICATION value = 56.1*TV*N/W.

25. • The ester value is defined as the number of milligram of KOH required
to saponify the ester in 1 gm of sample.
• Formula:- Ester Value (EV) = ( BHCL – AHCL ) x 28.05/ W
where, BHCL: volume (mL) of HCL consumed by blank
AHCL: volumev (mL) of HCL consumed by actual test
W: weight (g) of sample taken
• The ester value is calculated by subtracting the acid value of an oil from the
saponification value.

26. • Definition-
The number of grams of iodine taken up by 100 grams of fats or oils.
• Principle-
It is determined by treating the given sample of fats or oil with iodine
in ethanol of mercuric chloride. Unreacted iodine is then calculated.
It gives the idea of degree of unsaturation present in sample.
• It can be calculated by two methods-
1)Hubl’s method 2)Wij’s method

27. 1)Hubl’s method-
Fat or oil sample is dissolved in CCL4 and is treated with excess of std solution of ethanolic iodine in presence
of mercuric chloride. Unused iodine is then calculated by titration with std sodium thiosulphate solution.
2)Wij’s method-
- Significance of iodine value: It tells the degree of unsaturation present in fat or oil. Higher the iodine value,
highly unsaturated the given fat is. It also gives an idea of drying characters of fat and oil. It also helps in
determining adulteration in given sample of fat.
 Iodine value of non drying oil- 85 to 105
 Semi- drying oils- 105 to 120
 Drying oils- above 120

28. • It is the mg of KOH required to acetic acid liberated by hydrolysis of 1g of acid acetylated
substances.
• Acetyl value = 1335 (b-a)/ (1335-a)
Where, a: saponification of the substance
b: saponification value of acetylate substance
• Acetyl value = mole amount of free fatty acids
• Significance: It is the measure of hydroxy acid in lipids

29. • Richert Meissl (RM) Value :- It is useful in
testing the purity of butter since it contains a good
concentration of volatile fatty acids (butyric acid,
caproic acid,caprylic acid).
• P so it is defined as the ml of 0.1 N KOH required to
completely neutralized the soluble volatile fatty acid
distilled from 5 g fat.
• e.g. :- butter (short chain fatty acids) RM value (25-30)
• Significance :-
 It is a measure of water soluble strain volatile fatty.
 Acids, specially butyric and caproic acid present in oil
or fat.
 Butter fat contain butyric acid, glycerides and no other.
 Fat contain it, so RM value is high for butter fat.