Pectin
Pectin
Pectin is a complex carbohydrate component
found in nature in the middle lamella of plant cells. Chemically, pectin is a
neutral methoxy ester of pectic acid. Pectins are polyuronides and consist of
mixture of pectic substances like protopectin, pectin, pectinic acid and
calcium pectate Ash They are obtained from the inner portion of the rind of
citrus fruits or other vegetative matter, such Acid insolul as sun- flower,
papaya etc. Pectin is a reversible Colloid i.e. it may be dissolved in water,
Loss on dryi precipitated dried and redissolved, without altering its physical
properties. Pectin, by addition of Microbial li water, forms the lumps which on
heating convert into solution. The solution is clear to transmitted light and
cloudy to reflected light. Under certain conditions, in presence of sugar and
acid, it forms jelly like mass.
Pectin
is available from number of plants, belonging to different families. Following
are few Odour - important sources of pectin with content
Lemon peel
- 10 - 15 per cent
Orange peel –
10 - 12 per cent
Apple pomace
- 10 - 15 per cent
Carrots -
10.0 per cent
Sunflower-heads - 05.0 per
cent
Papaya, guavas and mangoes are also rich
sources of pectin. Pectin has several industrial and pharmaceutical
applications. Most of the requirement is met by import. In India, very a few
units are manufacturing pectin on commercial scale. The USA, Switzerland and
other European countries are producing pectin either from citrus peels or from
apple pomace. Pectin is standardised on "jelly grade' i.e. it's 'setting
power' by the addition of sugar (100, 150 and 200 jelly grades are supposed /й
be standard grades for food and medicinal use).
Biological
Source
Pectin is the purified carbohydrate product obtained by acid
hydrolysis from inner portion of the rind of citrus peels i.e. Citrus Simon or
Citrus aurantium, family Rutaceae.
Method of
Manufacture
Depending upon the raw material from which it is to be isolated
the process of manufacture 1- 10 per cer needs suitable modification. The type
of pectin (i.e. low or high methoxy group) needed should be considered.
Following is the general process for isolation of pectin from citrus peels.
The preserved or fresh lemon peels are heated with 20 times its
weight of water at 90°C for 30 minutes. The pH required for maximum extraction
is 3.5 - 4.0. The pH can be adjusted by lactic citric or
tartaric acids. The peels after boiling are pressed and solution is cleared by
settling or ifugation. Starch and proteins are removed by suitable enzymic
hydrolysis and the solution is heated to deactivate the enzymes and decolorized
with active carbon or any other suitable agent. Pure pectin is precipitated out
by using water soluble organic solvent, washed again and dried in acuum. Pectin
is incompatible with calcium, so necessary precaution should be taken to keep
it may from its metallic salts throughout the process of extraction. It is
packed in the containers or ethylene bags for marketing.
1.
Pectin is used as an adsorbent in
the treatment of diarrhoea and as a haemostatic for internald external
haemorrhage.
2.
It is used as an emulsifying agent, a gelling
agent in acid medium, and as a ۔ ۔ plasma substitute.
3.
In food industry, it is used as a thickening
agent for sauces, jams, ketchups, etc. need by sim is extensively used in
cosmetic preparations.
4.
Pectin is more stable in acidic
medium. Pectin in combination with gelatin has been suggester for use as an
encapsulating agent in pharmaceutical formulations to promote Sustained
release.
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