1. P R E P A R E D B Y - S A H I L C H O V A T I Y A
B . P H A R M S E M - 3
G U I D E B Y : M R S . P O O J A K H A N P A R A
A K S H A R - P R E E T I N S T I T U T E O F P H A R M A C Y
3. Pectin is a purified polysaccharide substance
obtained from the various plant sources such as
inner peel of citrus fruits, apple, raw papaya, etc.
4. Lemon and oranges are mostly grown in India, Africa
and other tropical countries.
Apple is grown in the Himalayas, California, many
European countries and the countries located in the
Mediterranean climatic zone.
5. In general, the preserved or freshly obtained lemon peels
are gently boiled with approximately 20 times its weight
of fresh water maintained duly at 90°C for duration of 30
min.
The effective pH (3.5–4.0) must be maintained with
food grade lactic acid/citric acid/tartaric acid to achieve
maximum extraction.
Once the boiling is completed the peels are mildly
squeezed to obtain the liquid portion which is then
subjected to centrifugation to result into a clear solution.
6. From this resulting solution both proteins and starch
contents are suitably removed by enzymatic hydro-lysis.
The remaining solution is warmed to deactivate the
added enzymes. The slightly coloured solution is
effectively decolourized with activated carbon or bone
charcoal.
Finally, the pectin in its purest form is obtained by
precipitation with water-miscible organic solvents (e.g.
methanol, ethanol, acetone, etc.), washed with small
quantities of solvent and dried in a vacuum oven and
stored in air-tight containers or poly bags.
7. Appearance : Coarse or fine - powder
Colour : Yellowish white
Odour : Practically odourless
Taste : Mucilaginous taste
8. Pectin occurs naturally as the partial methyl ester of
a (1→4) linked (+) – polygalacturonate sequences
interrupted with (1-2)–(-)– rhamnose residues. The
neutral sugars
That essentially form the side chains on the pectin
molecules are namely: (+) galactoe, arabinos, xylose
and fructose.
9. A 10% (w/v) solution gives rise to a solid gel on
cooling.
A transparent gel or semigel results by the
interaction of 5 ml of 1 % solution of pectin with 1 ml
of 2 % solution of KOH and subsequently setting
aside the mixture at an ambient temperature for 15
min. The resulting gel on acidification with dilute
HC1 and brisk shaking yields a voluminous and
gelatinous colourless precipitate which on warming
turns into white and flocculent.
10. It is emplyed mostly as an intestinal demulscent. It is
believed that unchanged molecules of
polygalacturonic acids may exert an adsorbent action
in the internal layers of the intestine, there by
producing a protective action along with Kaolin to
prevent and control diarrhoea.
As a pharmaceutical aid pectin is used frequently as
an emulsifying agent and alo as a gelling agent
preferably in an acidic medium.