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With the generic term of pectin we mean all the poligalatturonic acids, esterified with methylic alcohol at different neutralization degree. Molecular weight, viscosity and behavior in aqueous solution are variable. In presence of saccharine and of small quantities of organic acids (usually citric acid), the pectins gelatinize.

This property is exploited by the agrofood and pharmaceutical industry (hemostatic production, antidiarroheic, etc.) In 1825 Braconnot found that pectin is the main component of many fruits, in which it's found under protopectina form, that is pectin linked to cellulose. In oranges it's one third of the weight. It's the most important commercial element in the citrus fruit peel.

The protopectin can be separated by acid hydrolysis from cellulose. The pH, the temperature and the extraction time of this hydrolysis depend on the ripening degree of the fruits.

Varying the industrial production techniques it's possible to obtain different kind of pectins, at rapid or slow hold, at low metossilic tenor, able to gelatinize even without sugars.
Pectins at rapid hold are used in the jams made with berries, that tend to "float" if it doesn't happen a rapid gelatinization. Pectins for pharmaceutical use derive from an ulterior purification. The pectins at slow hold are used in the food industry.

The citrus fruit pulp in some fruit, especially in the lemon, grapefruit and bergamot, fresh or desiccated, are an excellent raw materials for the pectin extraction. The concentrated pectic extract or liquid pectin can be used directly in the jam preparation. The powder pectin is largely used in the food preparation. It can be obtained by an alcohol precipitation or with an aluminium salt, followed by washing with alcohol-acid to eliminate the aluminium and with pure alcohol to eliminate the precipitating mineral acid.