3. LIPIDS
Lipids are the structural and functional building blocks of the
living cells and they are made up of hydrocarbons with highly
reduced form of carbon.
Or
Lipids are the substances of animal or plant origin and comprise
of (a). fixed oils, (b).fats, (c). waxes and their derivatives.
Examples of Lipid :- Fats, oils,
waxes ,certain vitamins (such
as A, D, E and K), hormones
and most of the call
membrane that is not made
up of protein.
4. LIPID STRUCTURE
Lipids are the polymers of
fatty acids and that
contain a long, non-polar
hydrocarbon chain in
which the tail is
hydrophobic in nature
and with the small polar
head of molecule
carboxyl group or
containing oxygen, which
is hydrophilic in nature.
5. PROPERTIES OF LIPIDS
• Lipids are oily greasy, non-polar molecules, stored in the adipose
tissue of body.
• They are a heterogeneous group of compounds, mainly composed of
hydrocarbon chains.
• They are energy rich organic molecules, which provide energy for
different life processes.
• Insoluble in water but soluble in organic solvents.
• Hydrophobic or amphiphilic compounds.
• Fixed oils and fat float in water since their specific gravity less than
one.
• Produce permanent stain on the paper.
• Fixed oil and fat are nonvolatile and can’t be distilled without their
decomposition.
• They are significant in biological systems as they form a mechanical
barrier dividing a cell from external environment known as the cell
membrane.
6. SOURCES OF LIPIDS
• Found in all living organisms including humans,
plants and animals.
• Lipids exists in tissues in many forms.
• Simple lipids are often part of large aggregates
in storage tissues, such as oil bodies or adipose
tissue.
• In plants lipids are stored in the form of
triglycerides. The most known is jojoba, which
stores its seed lipid as a liquid wax.
• In oilseeds(sunflowers, linseed) the cotyledons
of the embryo are the major sites of lipid
accumulation.
• Endosperm of the bean, coriander or carrot, is
the main site of lipid accumulation.
• In tobacco, both embryo and endosperm
tissues store lipids.
Human tissues containingfats
Jojoba seeds oil
Linseed oil
Sunfloweroil
Coriander seeds oil
-Tobacco plants and
seed-
7. FUNCTIONS & USES OF LIPIDS
• Lipids are important source of metabolic energy (ATP) so they are the most energy
rich of all the nutrients which provide energy for different life processes.
• They form the structural components of the cell membranes.
• They serve as the biological carriers for the absorption of fat soluble vitamins A,D, E
and K.
• Lipids are also act as lubricants for the passage of food.
• Maintenance of temperature.
• In laxatives.
• In the base of oil injections.
• In edible/food oils.
• In antiseptic preparations.
• In the treatment of rickets.
• In varnishes and paint industries.
• In cosmetics.
• Also possesses antibacterial properties.
9. FATTY ACIDS
• Fatty acids are the important component of the lipids.
• These are the water insoluble ,long chain hydrocarbons having carboxyl
group on one end & methyl group on the other end.
• All fatty acids are building blocks of lipids including fats, phospholipids,
glycolipids, cholesterol, waxes etc.
• Fatty acids having carbon atom from –
1-6 are called short chain FAs.
6-12are moderate chain FAs.
13-19 are long chain FAs.
19C onwards are very long chain FAs.
• Moderate chain FAs are also abundance in human body fluid, most frequent
is 16C (Palmitic acid).
10. CLASSIFICATION OF FATTY ACIDS
Fatty Acids
Fatty acids are classifieds according to the no. of carbon atoms & presence
or absence of double bond.
Monosaturated
Fatty Acids
Unsaturated
Fatty Acids
Polysaturated
Fatty Acids
Saturated Fatty
Acids
SATURATED FATTY ACIDS
• These are the fatty acids which contain
only single bonds . Examples:- Palmitic
acid , stearic acid etc.
11. Non-essential Fatty Acids
• From dietary point of view, saturated
FAs are synthesized by human body,
no need to provide as external
source & not so essential as
unsaturated FAs, so they are called
non-essential fatty acids.
Unsaturated Fatty Acids
• These are the fatty acids which contain
one or more double bonds with a
terminal carboxyl group unlike saturated
FAs.
• A single double bond is termed as
Monosaturated FAs.
• More than one double bond is termed
as Polysaturated FAs.
12. Essential Fatty Acids
• From dietary point of view , unsaturated
fatty acids must be taken by human from
external sources such as dry fruits & plant
oils.
• These can’t be synthesized in the human
body so they are very essential and called
essential FAs.
Physical Properties of FAs
• Physical State & Melting Point- The melting point of FAs depends upon the
chain length (the longer is the chain ,the higher is the melting pt. & vice versa)
& degree of unsaturation (the greater the no. of double bonds, the lower is the
melting pt.). That’s why the acids with small chain length & with high
unsaturation are generally liquids at room temperature.
• Solubility – It also depends upon the chain length (solubility decreases with
increase in the chain length) & degree of unsaturation (solubility of FAs
increases with the increase in the double bond).
• Boiling Point – The boiling point of FAs increases with the increase in the
chain length.
13. Chemical Properties of FAs
• Salt Formation- FAs when treated with alkalies form their Salts.
R-COOH + NaOH
Fatty acid Alkalies
Metallic salts of higher FAs are called soap. Na & K salts are emulsifying agents,
while Ca & Mg salts are insoluble in water.
• Detergent Formation- Reduction of COOH group of FAs produced alkyl
alcohols, which can be sulphated or sulphonated to form alkyl sulphonates
which act as Detergent.
R-COOH + 2H2 R-CH2OH + H2O
R-CH2OH + Na R-CH2-ONa R-CH2-SO2ONa
Alkyl alc. Sod. Alkyl sulphonate
Unlike soaps the detergents are stable & do not form insoluble salts with Ca &
Mg.
R-COONa +
Salt
H2O
Water
14. • Ester Formation- Fatty acids form esters when treated with alcohols in the
presence of dehydrating agents like conc. H2SO4 or anhydrous HCL.
R-COOH + HO-R R-CO-OR + H2O
Most important esters are with glycerol. Mono, di, tri glycerides are the essential
constituents of fats and oils.
• Rancidation- Addition of O2 on double bond gives peroxides. Peroxides can
undergo cleavage to form bad smelling aldehyde, ketones & acids. Thus on
exposure to air, light & warmth, fats undergo autoxidation. The process is
known as Rancidation which is prevented by Vitamin E.
CH3(CH2)7CH=CH(CH2)7COOH CH3(CH2)7CHO + COOH(CH2)7COOH
• Formation of Prostaglandin- Prostaglandins are synthesize within the body
from unsaturated fatty acids & have been found to occur in many organs for
example-seminal plasma, genital glands. They play a hormonal role & control
different biological phenomenon such as smooth muscles contractions ,
labour inducing agent, involved in blood clotting and mucosal protective
agents.
O2
Chemical Properties of FAs
15. FATS & OILS
• If a substance is liquid at 15-16.5 C it is called Fixed oil and solid or semisolid
at the above this temperature, it is called Fat. For example lard, fish oil, ghee,
olive oil etc.
• They are made from two kinds of molecules: Glycerol (a type of alcohol) and
various straight chained monocarboxylic acids known as fatty acids. The fatty
acids of natural fats have 4-24C atoms (and any even numbers). These fatty
acids may be saturated, monosaturated, polysaturated or cyclic unsaturated.
• Fats and oils are commonly called triglycerides or triacylglycerol. Fats normally
saturated fatty acid esters and fixed oils mostly composed of unsaturated
fatty acid esters.
16. Properties of Fats & Oils
• Fixed oils are thick, viscous, yellow-colored liquids with a characteristic Odour.
• They are non- volatile and cannot be distilled.
• They do have food value and can be saponified.
• They turn rancid on storage due to free acidity.
• Fixed oils and fats are insoluble in water and ethyl alcohol, but soluble in
organic solvents like chloroform, ether and benzene etc.
• Fats and oils are esters of glycerols and fatty acids. The oils and fats also
contain various quantities such as vitamins, sterols, antioxidants,
phospholipids, pigments and traces of hydrocarbons, and ketones,
responsible for specific odours and flavors of these oils.
• Physiologically, they are emollients and demulcents.
• Fats are mostly obtain from animal sources and solids at room temperature,
oils are mostly obtain from plant sources and liquids at room temperature.
There are notable exceptions, such as cocoa butter, which is a solid vegetable
oil, and cod liver oil, which is a liquid animal fat.
17. Classification of Oils & Fats
An oil that
hardens to a
tough, solid film
after a period of
exposure to air,
contains more
than 50% of
polysaturated
acids, a key
component of oil
paint &
varnishes. For
example, linseed
oil, hemp, walnut
oils etc.
An oil which
partially
hardens when
it exposed to
air and contains
20-50% of
polysaturated
acids. For
example, castor
oil, mustard oil,
sesame oil.
An oil that does
not harden when
it exposed to air
and contains less
than 20% of
polysaturated
acids. And use in
food, skincare
products and to
condition pliable
materials such as
leather boots. For
example, olive
oil, almond oil,
peanut oil etc.
Examples
of fats
include
peanut,
cocoa
butter
and
coconut
oil etc.
Fats – Bone
tallow.
Oils – Cod liver
oil, shark liver
oil and whale oil
etc.
Fats – Lard , mutton-
tallow and butter
suet etc.
Oils – Lard oil, neat
foot oil etc.
18. Types of Fats
• Saturated fat - Saturated fat is solid at room temperature, which is why it is also
known as "solid fat." It is mostly in animal foods, such as milk, cheese, and meat.
Poultry and fish have less saturated fat than red meat.
Saturated fat is also in tropical oils, such as coconut oil
, palm oil, and cocoa butter. You'll find tropical oils in
many snacks and in non-dairy foods, such as coffee
creamers and whipped toppings. Foods made with butter,
margarine, or shortening (cakes, cookies, and other desserts)
have a lot of saturated fat. Saturated fat can raise your cholesterol.
• Trans fat - This is a fat that has been changed by a process called hydrogenation.
This process increases the shelf life of fat and makes the fat
harder at room temperature. Some animal-based foods have
small amounts of naturally occurring trans fats. Most trans fat
comes from partially hydrogenated oils (PHOs). PHOs cannot be
used in food sold in Canada. Trans fat can raise your cholesterol,
so eat as little trans fat as possible.
19. • Unsaturated fat - Unsaturated fat is liquid at room temperature. It is mostly in oils
from plants. If you eat unsaturated fat instead of saturated fat, it may help improve
your cholesterol levels. Try to eat mostly unsaturated fats. Monounsaturated fat and
polyunsaturated fat are types of unsaturated fat.
Monounsaturated fat: This fat is in avocado, nuts, and vegetable oils, such as
canola, olive, and peanut oils. Eating foods that are high
in monounsaturated fats may help lower your "bad“
LDL cholesterol. Monounsaturated fats may also keep "good"
HDL cholesterol levels high. But eating more unsaturated fat
without cutting back on saturated fat may not lower your cholesterol.
Polyunsaturated fat: This type of fat is mainly in vegetable oils such as safflower,
sunflower, sesame, soybean, and corn oils. Polyunsaturated fat is also the main fat
found in seafood. Eating polyunsaturated fat in place of saturated fat may lower LDL
cholesterol. The two types of polyunsaturated fats are omega-3 and omega-6 fatty
acids. Omega-3 fatty acids are found in foods from plants like soybean oil, canola oil,
walnuts, and flaxseed. They are also found in fatty fish and shellfish as
eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
Salmon, anchovies, herring, sardines, Pacific oysters, trout,
Atlantic mackerel, and Pacific mackerel are high in EPA and DHA
and lower in mercury.
20. o Omega-6 fatty acids are found mostly in
liquid vegetable oils like soybean oil, corn oil, and safflower oil.
A no. of parameters are used for analysis of fats & oils which are included under
physical constant (include viscosity, specific gravity, refractive index, solidification point
etc.) and chemical constant ( include iodine value, acid value, peroxide value,
saponification value, unsaponifiable matter etc.). Following is a brief idea about some of
the analytical parameters grouped under chemical constants.
• Iodine value: It is defined as the weight of iodine absorbed by 100 parts by weight
of the sample of fat or oil. It is a measure of the extent of unsaturation.
• Saponification value: It is defined as the no. of milligrams of potassium hydroxide
required to neutralise the fatty acids resulting from complete hydrolysis of 1g of
sample of oil or fat.
• Hydroxyl value: It is defined as the no. of milligrams of potassium hydroxide
required to neutralise the acetic acid capable of combining by acetylation with 1g
sample of fat or oil.
Analytical Parameters for Oils & Fats
21. • Acetyl value: It is the no. of milligrams of potassium hydroxide required to neutralize
the acetic acid obtained when 1g of sample acetylated oil is saponified. Except castor
oil (acetyl value 150), most of the oils and fats have low acetyl value (3-15).
• Unsaponifiable matter: It is the matter present in oil , which after saponification by
caustic alkali and subsequent extraction with an organic solvent, remains non-volatile
on drying at 80 degree C.
• Acid value: It is defined as the no. of milligrams of potassium hydroxide required to
neutralize the free acids present in 1g sample of fat or oil. Generally , rancidity causes
free fatty acids liberation, hence acid value is used as an indication of rancid state.
• Peroxide value: It is measure of peroxides present in oil. A peroxide value is
generally less than 10 mEq/kg in fresh samples of oil, due to temperature or storage,
rancidity occurs causing increase in peroxide values.
• Kreis test (rancidity index): Due to rancidity , epihydrin aldehyde or malonaldehyde
are increased which are detected by kreis test using phloroglucinol which produces
red color with the oxidized fat.
• Ester value: It is defined as no. of milligrams of potassium hydroxide required to
combine with fatty acids which are present in glycerides from 1g sample of oil or fat.
Difference between saponification value and acid value is ester value.
22. • Reichert Meissl value: This value is a measure of volatile water soluble acid
contents of the fat. It is defined as no. of milliliters N/10 potassium hydroxide solution
required to neutralize the volatile water soluble fatty acids obtained by 5g fat.
• Polenski value: It is defined as the no. of milliliters of N/10 potassium hydroxide
solution to neutralize water insoluble , steam ditillable acids liberated by hydrolysis of
5g of fat.
• Acid value: - It is used to measure the free fatty acids present in fats and oils and
also known as neutralization number. Free fatty acids in fats and oils are harmful for
human.
Principle: It is determined by directly titrating the oil/fat in an alcoholic medium
against standard potassium hydroxide /sodium hydroxide solution.
Significance: The value is a measure of the amount of fatty acids which have been
liberated by hydrolysis from the glycerides due to the action of moisture, temperature
and/or lipolytic enzyme lipase.
Procedure: 1. Mix the oil/melted fat thoroughly before weighing .
2. Weigh accurately about 5-10g of cooled oil sample in a 250 ml conical flask and add
50ml-100ml of neutralized hot ethanol & 1ml of phenolphthalein indicator soln.
Some Methods of Analysis
23. 3. Boil the mixture for 5 minute. And do titration while hot against standard alkali
solution shaking vigorously until the end point comes.
Acid value= 56.1VN where , V = vol. in ml of standard KOH/NaOH soln.
N = Normality of KOH/NaOH son.
W = Weight in g of the sample.
• Iodine value: It is the no. of gm of iodine absorbed by 100 gm of oil/fat , when
determined by using Wij’s solution.
Principle: The oil/fat sample taken in carbon-tetrachloride is treated with a known
excess of iodine monochloride solution in glacial acetic acid (Wij’s solution). The excess
of iodine monochloride is treated with potassium iodide and the liberated iodine
estimated by titration with sodium thiosulphate solution.
Significance: The iodine value is a measure of the amount of unsaturation(no. of
double bond) in a fat.
Procedure: 1. Weigh an appropriate quantity of the dry oil/fat into a 500ml conical
flask with glass stopper.
2. Add 25ml of carbon tetrachloride. Mix the content well. Add 50-60% of Wij’s soln,
over that actually needed.
W
24. 3.Pipette 25ml of Wij’s soln. and replace the glass stopper after wetting with potassium
iodine solution.
4. Swirl for proper mixing and keep the flasks in dark for half an hour for non-drying and
semi-drying oils and one hour for drying oils.
5.Carry out a blank simultaneously. After standing, add 15ml of potassium iodide soln. ,
followed by 100ml of recently boiled and cooled water, rinsing in the stopper also.
6.Titrate liberated iodine with standardized sodium thiosulphate solution, using starch as
an indicator at the end until the blue colour formed . Blank sample is also conducted as
per the same manner.
Calculation - Iodine value = 1.69(B-S)N
Where, B= vol. in ml of standard sod. Thiosulphate solution required for the blank.
S= vol. in ml of standard sod. Thiosulphate solution required for the sample.
N= Normality of the standard sod. Thiosulphate solution.
W= Weight in g of the sample.
W
25. • Saponification value: The saponification value is the no. of potassium hydroxide
required to saponify 1gm of oil/fat.
Principle: The oil sample is saponified by refluxing with a known excess of alcoholic
potassium hydroxide solution. The alkali required for saponification is determined by
titration of the excess potassium hydroxide with standard hydrochloric acid.
Significance: It is an index of mean molecular weight of the fatty acids of glycerides
comprising a fat. Lower the saponification value, larger the molecular weight of fatty
acids in the glycerides and vice-versa.
Procedure: 1. 25ml of the 0.5M KOH added into the small beaker.
2. Solvent was added to the same level of final volume.
3. Placed it in boiling water and bathed for 30 minutes.
4.Allow to cool. Add 3 drops of phenolphthalein and titrated with 0.5N HCl.
Calculation: Saponification value= 56.1(B-S)N
Where, B= vol. in ml of standard HCl solution required for the blank. S= vol. in ml of
standard HCl solution required for the sample. N= Normality of the standard HCl soln.
W= Weight in g of the sample.
W
26. • Ester value:- It is the no. of mg of KOH required to saponify the ester present in 1gm
of the substances.
Principle: It is determined by titrating the sample of oil & fat in alcoholic medium
against 0.5M HCl.
Significance: The ester value shows the amount of alkali consumed in the
saponification of the ester and is possible to identify and differentiate the fats with this
value.
Procedure: 1. Weigh accurately about 2g of sample & add 25ml of 0.5M ethanoic
KOH.
2. Boiled under reflux condenser on a water bath for 1 hour.
3.Then, add 20ml of water in it. Titrate the excess of alkali with 0.5M HCl using a
further 0.2ml of phenolphthalein indicator.
4. Repeat the operation without sample (blank reading).
5.The difference between the titrations represents the alkali required to saponify
the esters.
Ester value= Saponification value-Acid value
27. • Reichert- meissl value: It is useful in testing the purity of butter , since it contains a
good concentration of volatile fatty acids. It is defined as the ml of 0.1N KOH required
to completely neutralize the soluble volatile fatty acids distilled from 5g fat.
Principle: Fat is saponified using glycol alkali solution and acidified by sulphuric acid to
liberate free fatty acids.
Procedure: 5g of fat
distillation
volatile fatty acids is filtered for separation of water and water insoluble fatty acids.
Water soluble fatty acids is titrated with alkali (0.1N KOH)to neutralize and to give RM
value.
Significance: It is a measure of water soluble steam volatile fatty acids, specially
butyric and caproic acids present in oil/fat. Butter fat contain butyric acid glycerides,
and no other fat contain it, so RM value is high for butter fat (25-30). These
determination have been used for analysis of butter.
28. Castor Oil
Synonym : Ricinus oil.
Family : Euphorbiaceae.
Biological source : It is fixed oil obtained by cold expression of seeds of Ricinus communis.
Physical properties : Type- Fixed oil
Odor- Soft & faint.
Color- Pale yellow to colorless.
Taste- Highly unpleasant.
Solubility- Soluble in organic solvents like benzene, chloroform but insoluble in other mineral oils.
Acid value- Not more than 2.
Iodine value- Between 82 to 90.
Solidifying point = -10 to -18 degree C.
Viscosity- 6-8 poises.
Physical Standards : Weight per ml- 0.945 to 0.965g.
Acetyl value- Not less than 143.
Saponification value- Between 176 and 187.
Hydroxyl value- Not less than 150.
Refractive index- Between 1.4758 and 1.4798.
Chemical Constituents : Triglycerides of Ricinoleic acid [CH3 (CH2)6 CHOH CH2 CH=CH(CH2)7 COOH] (80%). Other
glycerides of Isoricinoleic acid, linoleic acid, stearic acid, isostearic acid. Others- heptaldehyde, undecanoic acid, sebacic
acid.
Identification Tests : 1. It is mixed with half volume of light petroleum ether (40-60 degree).
2. Add to the oil an equal volume of ethanol, clear liquid is obtained on cooling at 0 degree C and on storage for 3 hour-
Liquid remain clear (Distinction from other fixed oil).
29. Preparation of Medicinal Castor oil : Castor seed contains about 30-40% fixed oil. Castor oil can be extracted from
castor beans by either: 1. Cold Expression method , 2. Solvent extraction, 3. combination of pressing and Extraction.
1. Cold Expression Method -
2. Solvent Extraction -
30. Uses of castor oil : 1. Purgatives (irritant action of ricin oleic acids, seed more cathartic action than oil).
2. Emollients (in preparation of lipsticks, perfumed hair oil , hair fixers).
3. Used in Abortification pastes (ricin oleic acid used in contraceptive creams and jellies).
4.Industrially – hydrogenated castor oil substitute for bees wax , carnauba wax in
preparation of ointments, creams and polishes. Dehydrogenated castor oil –linoleic
& alkyl resin preparation , primers & inks.
5. Atropine and cocaine suspended in castor oil for ophthalmic purposes.
Synonym : Hydnocarpus oil, Gynocardia oil.
Biological Source : Hydnocarpus oil is the fixed oil obtained by cold expression
method from ripe seeds of the plant Taraktogenos kurzii,
Hydnocarpus anthelmintica, H.pentandrus.
Family : Flacourtriceae.
Geographical Source : This plant is native of Myanmar, Thailand and east India. It is also found
in Sri Lanka and Bangladesh. In India , it is grown in Assam and Tripura.
Method of Preparation : Seeds are sub-ovoid , obtusely angular and 2cm in length ,
Chaulmoogra seed contain 40-45 % fixed oil. Fruits are collected once in 2-3 years. Peeled by knife- seeds are removed-
washed and dried in sun – seeds are cracked & decorticated by millet, hand hammer or by decorticator(to remove
testa)- kernel are grounded into paste and placed into a square jute bags & pile up one over another- oil is expressed by
hydraulic press- stored in airtight containers in cool place & away from light.
Chaulmoogra Oil
31. Description : Colour – Yellow to brownish yellow coloured liquid. Odour- Characteristic.
Taste- Acrid. State- It is soft white solid below25 degree Celsius.
Solubility- Soluble in organic solvent like CHCl3, benzene and slightly soluble in alcohol.
Chemical Constituents : It contains chemically esters of fatty acids of chaulmoogric acid (27%), hydnocarpic acid (48%),
gorlic acid and 20% of proteins, cyanophoric glycosides and glycerides of palmitic acids and oleic acid.
Physical Standards : Weight Per ml- 0.935 to 0.960g Acid value- Not more than 10
Saponification value – 195 to 213. Iodine value- 93 to 104
Refractive index- 1.472 to 1.476.
Medicinal uses : 1. It is useful in treatment of leprosy, psoriasis and many other skin disease , applied externally on the
affected area.
2. It is also useful for treatment of tuberculosis, rheumatism. Oil is used up to 15% in medicinal soap.
3. It is cyclopentyl unsaturated fatty acids are effective bactericidal against
Mycobacterium Tuberculosis , Mycobacterium Leprae.
32. Wool Fat
Synonyms : Lanolin , Adeps Lanae.
Biological Source: Hydrous wool fat is the purified fat like
substance obtained from the wool of Ovies aries.
Family: Bovidae.
Geographical Source: Lanolin is commercially manufactured in Australia,
U.S.A. and to a very less extent in India..
Method Of Preparation:• Raw wool contains 31% wool fibers, suint or wool sweat(chemically potassium salts of fatty
acids), 32% earthy matter and 25% wool grease or crude lanolin.
• Crude lanolin is separated by washing with sulphuric acid or suitable organic solvent or soap solution.
• It is further purified or bleached
• The product is known as anhydrous lanolin or wool fat
• Hydrous wool fat prepared by mixing anhydrous product with 30% water.
• Odour - faint and characteristic
Description: • Colour - whitish-yellow
• Taste – bland
solvent ether STANDARDS(Anhydrous lanolin)
• Acid value: not more than 1
• Saponification value: 90-105
• Solubility - insoluble in water - soluble in chloroform and
• Melting point: 34 to 44 degree Celsius
• Iodine value: 18-36
• Peroxide value: not more than 20
33. Chemical Constituents: • It contains mainly esters of cholesterol and isocholesterol with caranubic, oleic, myristic,
palmitic, lanoceric and lanopalmitic acids.
• It also contains 50% water.
Identification Test:
• 0.5g wool fat in chloroform + 1ml acetic anhydride+ 2 drops of
sulphuric acid Deep green colour indicates the presence of cholesterol.
Uses: • Used as water absorbable ointment base
• Used as a common ingredient and base for water soluble creams and cosmetics.
Waxes
• Waxes are esters of long-chain fatty acids and alcohols, unctuous , fusible,
variably viscous solid substances with characteristic waxy lustre.
• The fatty acids are same in wax and fats, but the difference being
saponification. Waxes are saponified only by alcoholic alkali but
the fats may be saponified either by alcoholic alkali or by aqueous alkali.
• Wax has a melting point above approx. 45 degree Celsius
(which differentiates waxes from fats and oil).
• In plants, waxes are generally found covering the external parts, like the epidermis of leaves and fruits,
where their main function is to prevent the loss of water.
• Waxes also produced by insects such as the honeycombs of bees and wasps.
• USES: Wax is used in pharmacy to make soft ointments harder and to prepare lip salves. The technical
uses of waxes are substantial, e.g. in shoe polishes and car waxes
34. Beeswax
Synonyms: Yellow wax, Cera alba.
Biological Source : Obtained from the honey comb of the
bees Apis mellifera and other species of Apis belonging to the family Apidae .
Geographical Source : It is produced in France, Italy, West Africa, India.
Preparation: 1) The combs and capping of honeycomb are broken and boiled in soft water.
2) These are then enclosed in a porous bag weighed to keep under water, the boiling causes oozing of the wax,
which get collected outside the bag and form a cake after cooling.
3) The debris on outer surface is removed by scraping.
4) The process is repeated several times and finally wax is skimmed off.
Description: Colour : Yellow to yellowish-brown Odour : Agreeable and honey-like
Extra features: Non crystalline solid. Soft to touch and crumbles under pressure of fingers to plastic mass. Under
molten condition, it can be given any desired shape. It breaks with a granular fracture.
Solubility: Insoluble in water. Soluble in hot alcohol, ether, chloroform, carbon tetrachloride, fixed and volatile oils.
Standards: M.P. : 62 to 65°c Specific gravity : 0.958 to 0.967
Acid value : 5 to 10 Saponification value : 90 to 103 Ester value : 80 to 95
Chemical constituents: It consists of esters of straight chain monohydric alcohols with straight chain acids. Indian
bees wax contains low acid value and European bees wax has acid value of 17-22.Constituent is myricin i.e. myricyl
palmitate 80%, free cerotic acid 15%, melissic acid and aromatic cerolein.
35. Identification test: Saponification cloud test: 0.5g bees wax + 20ml aq.
Caustic soda Boil for 10 minutes No turbidity is produced.
Uses: In preparation of ointments, plasters and polishes. Also used in the
manufacturing of candles, moulds in dental and electronic industries,
cosmetics for lip- sticks, face cream. Is an ingredient of paraffin ointment.
Adulteration:. Adulterated with colophony, hard paraffin stearic acid, Japan wax, spermaceti, carnauba wax.
Adulteration can be detected on the basis of solubility and melting point. The genuine wax should not give turbidity
when 0.5g of wax is boiled with 20ml of aqueous caustic soda for 10 minutes and cooled.
36. REFERENCE
Pharmacognosy, Nirali Prakashan, 54th Edition September
2017 by C.K. Kokate, A.P. Purohit & S.B. Gokhate.
Pharmacognosy and Phytochemistry-I, Nirali Prakashan, 1st
Edition April 2019 by Dr. Kuntal Das.
Internet Resources.
