Linseed, also known as flax, is a plant cultivated for its fibers and oil-rich seeds. The document discusses the history, cultivation, composition and uses of linseed oil. Linseed oil is extracted from the seeds and contains high amounts of linolenic acid. It is used widely in paints, varnishes, printing inks and other industrial applications due to its drying properties. The leftover oil cake is also used as cattle feed or organic fertilizer.

1. Sources of Oils and Fats
By
Hem Chander
Assistant Professor (Botany)
Career Point University Hamirpur (HP) 176041
hemchander78@gmail.com

2. Botanical name: Linum usitatissimum
Family: Linaceae
Common names: Flax, Alsi

3. •Linseed is one of the earliest plants to have
been under cultivation for the extraction of
fibres.
•Flax fiber is extracted from the bast beneath the
surface of the stem of the flax plant.
surface of the stem of the flax plant.
• Flax fiber is soft, lustrous, and flexible; bundles
of fiber have the appearance of blonde hair,
hence the description "flaxen" hair. It is stronger
than cotton fiber, but less elastic..

4. •The plant also yields oil of commercial importance. It is
grown widely in many parts of the world, both in
tropical and temperate zones.
•The crop is grown in hot dry regions mainly for oil
production, and in temperate regions for high grade
production, and in temperate regions for high grade
fibre.
•The varieties grown for fibre are usually different from
those for oilseed production

5. • Two main geographical groups corresponding to the oldest areas of
cultivation and the centres of diversity have been recognized.
• Linseed has been cultivated since antiquity in the Mediterranean coastal
lands, Asia minor, Egypt, Algeria, Spain, Italy and Greece. In all these areas
only fibre flaxes are cultivated.
• The second group comprises South-west Asia including Afghanistan and
India; only oil types are grown in these areas.
India; only oil types are grown in these areas.
• In Asia minor and South Russia, transitional forms are cultivated for both
fibre and oil.
• Presently, the linseed crop is cultivated in India, Pakistan, China, Japan,
Australia, Argentina, Canada and the United States of America.
• The leading linseed producing states in India are Madhya Pradesh, Uttar
Pradesh, Maharashtra, Rajasthan, Bihar, West Bengal and Orissa.

7. • The oil is contained in the cells of the two large cotyledons
intermixed with aleurone layer of seeds. The oil content of the
seed is between 33 and 43 percent.
• The oil extraction is carried out mostly by bullock driven
ghanis (Kolhu) which are not useful in extracting all the oil
available and as such a large part of the oil is left in the cake.
Extraction of oil
available and as such a large part of the oil is left in the cake.
• In recent years power driven rotary ghanis, hydraulic presses
and expellers are used for oil extraction.
• In general before crushing, the seeds are rolled into meal and
cooked in a steam jacketed trough.

8. • The oil content of the seed varies according to the variety of
linseed and climatic conditions under which the crop has been
raised.
• If protected from air and light, the oil has a good keeping quality.
On exposure to air, however, it is converted into an elastic solid
known as linoxyn.
Chemical & Nutritional Composition
• Linseed oil is a yellowish brown liquid, characterized by the
presence of a high percentage of linolinic acid (30-60 percent).
• Other fatty acids are stearic and palmitic (6-16 percent), oleic 03-
36 percent), linoleic (10-25 percent), and traces of myristic and
arachidic acid. Crude linseed oil yields 0.25 percent phosphatides
consisting of lecithin and ceplhlin.

9. Uses
• The oil is mostly used in the paint and varnish industry as it is a drying oil. A
mixture of lac: linseed oil: red lead in the proportion 80: 160: 12 gives the
most satisfactory lac-linseed-oil varnish.
• It is also used in the manufacture of linoleum, oil-cloth, printing and
lithographic inks and soft soaps.
• The oil is employed in the preparation of lubricants, greases and polishes.
• Raw linseed oil is used in pharmaceuticals as an emollient, expectorant and
diuretic
• Because of the hydrophilic property of mucilaginous substance in the seed
coat, the whole seed is used as a laxative as it draws fluid from body tissue
with which it is in contact.
• The extracted mucilage is often used in the cosmetics and pharmaceutical
industries as a demulcent.

10. • Linseed oil mixed with limewater is applied to burns.
• Oil cake is used as a good organic manure. It can be mixed with other
inorganic manures for increasing the fertility of soil. Oil cake is palatable,
protein rich (30 per cent) and used as a cattle feed.
• It has slightly laxative action. But this possesses some poisonous properties,
so only small quantities are fed to cattle. The poisonous effect of the seed is
due to the presence of a cyanogenetic glycoside, phaseolunatin (linamarin).
Cattle poisoning is caused by the hydrocyanic acid or prussic acid which is
released by the activity of the enzyme linase on linamarin.
released by the activity of the enzyme linase on linamarin.
• Hot pressed linseed cake is harmless as the linamarin fraction is not
hydrolysed to HCN owing to the denaturation of the enzyme linase during
cooking.
• Quite often the raw linseed oil is heated to 90-105°C in the presence of driers
such a the salts of certain metals like lead, manganese, cobalt and zinc. Boiled
oils dry at a faster rate and form a smooth and lustrous film and are preferred
for most industrial uses, e.g., in the paint, lacquer and varnish industry.