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Contents :<br />
1 introduction<br />
2 Biology<br />
3 Chemistry<br />
4 Sources and production<br />
5 Uses<br />
6 Legal status<br />
7 History<br />
1 – Pectin :<br />
Pectin<br />
Pectin (from Greek - pektikos , " congealed, curdled " ) is a<br />
structural hetero poly saccharide contained in the primary cell walls<br />
of terrestrial plants. It was first isolated and described in 1825 by<br />
Henri Braconnot . It is produced commercially as a white to light<br />
brown powder, mainly extracted from citrus fruits, and is used in food<br />
as a gelling agent particularly in jams and jellies. It is also used in<br />
fillings, sweets, as a stabilizer in fruit juices and milk drinks and as a<br />
source of dietary fiber .<br />
2 – Biology :<br />
Copyright © Tarek Kakhia. All rights reserved. http://tarek.kakhia.org<br />
In plant cells, pectin consists of a complex set of<br />
polysaccharides that are present in most primary cell walls and<br />
particularly abundant in the non - woody parts of terrestrial plants.<br />
Pectin is present not only throughout primary cell walls but also in the<br />
middle lamella between plant cells where it helps to bind cells<br />
together . The amount , structure and chemical composition of pectin<br />
differs between plants, within a plant over time and in different parts<br />
of a plant. During ripening , pectin is broken down by the enzymes<br />
pectinase and pectinesterase ; in this process the fruit becomes softer<br />
as the middle lamella breaks down and cells become separated from<br />
each other. A similar process of cell separation caused by pectin<br />
breakdown occurs in the abscission zone of the petioles of deciduous<br />
plants at leaf fall.<br />
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