Pectin

Pectins (from Greek pectós = solid, coagulated) are naturally occurring polysaccharides which are essentially composed of galactose units which are glycosidically linked to each other. The biosynthesis of pectins starts from glucuronic acid. Pectin can be composed of a few hundred but also of a few 100,000 units. Depending on the size of the molecule, the physical behaviour of the substance also changes.

The carboxyl groups of the galactose units are partly esterified with methanol. The degree of their esterification and acetylation varies considerably. However, the degree of esterification has a decisive influence on the chemical properties. Therefore pectins are classified according to their average degree of esterification VE.low ester pectin has the highest gelling capacity.

The pectins are broken down by pectases or pectinases.

A distinction must be made:

• pectic acids: building blocks are polygalacturonic acids
• Pectins: In these, the carboxyl groups of the galacturonic acid units are partially methylated.
• Protopectins: Insoluble pectins in which the polygalacturonic acid chains are connected to each other via calcium or phosphoric acid.
• Amide Pectins: In these pectins pectin additionally contains certain nitrogen groups (amide groups).

Pectins are contained in all plant tissues capable of growth. They act as structural substances in the cell walls.

Pectin content in fruits

• apples 1-1,5 %.
• Apricots 1 % Apricots
• carrots 1,4 %
• Oranges 0,5-3,5
• Citrus peels 30 %

Pectins in food: Pectins are permitted as food additive in the EU under the number E 440 without any maximum quantity restriction (quantum satis).

They are mainly used because of their ability to gel in aqueous solution. Amide pectin forms stable gels with only a few molecules. These melt when heated and are used, among other things, for cake icing. Furthermore, they serve as fillers, stabilisers, coating and thickening agents.

Specifically, pectins are found in jams, marmalades, jellies, jam sugar and confectionery, desserts and ice cream, cake glazes, sauces and mayonnaise. Pectins are considered as harmless.

Pectins in medicine: Medically, this completely indigestible substance, which acts as a water-binding dietary fibre in the human organism, is used in diarrhoea and gastroenteritis. Pectins are also used in the treatment of wounds.

Pectins in pharmacy: In cosmetic products it is used as an inert thickener and emulsifier.

Switzerland: May not be used in jelly mini-cups.