DEFINITION

Pectin is a purified carbohydrate product obtained by aqueous extraction of appropriate edible plant material - usually citrus fruits or apples.

All green land plants contain pectic substances which in combination with cellulose are responsible for the structural properties of fruits and vegetables. Pectin consists mainly of galacturonic acid and galacturonic acid methyl ester units forming linear polysaccharide chains and is normally classified according to its degree of esterification.

In high (methyl) ester or HM-pectin a relatively high portion of the carboxyl groups occur as methyl esters, and the remaining carboxylic acid groups in the form of the free acid or as its ammonium, potassium, calcium or sodium salts; its useful properties may vary with the degree of esterification and with the degree of polymerization. Pectin in which less than 50% of the carboxyl acid units occur as the methyl ester is normally referred to as low (methyl) ester or LM-pectin. In general, low ester pectin is obtained from high ester pectin by a treatment at mild acidic or alkaline conditions.

Amidated pectin is obtained from high ester pectin when ammonia is used in the alkaline deesterification process. In this type of pectin some of the remaining carboxylic acid groups have been transformed into the acid amide. The useful properties of amidated pectin may vary with the proportion of ester and amide units and with the degree of polymerization. Commercial pectin is normally blended with sugars for standardization purposes, and some types may contain suitable food grade buffer salts required for control of pH and desirable setting characteristics.

FOOD REGULATORY STATUS

As a constituent of all land plants, pectin has been part of the human diet from the origin of man. Pectin has been evaluated and cleared toxicologically by JECFA (the Joint FAO/WHO Expert Committee on Food Additives). A group ADI "not specified" was established for pectins and amidated pectins, meaning that from the toxicological point of view there are no limitations on the use of pectins and amidated pectins.

In most countries, food legislative authorities recognize pectin as a valuable and harmless food additive. If regulated, permitted use levels are generally in accordance with "Good Manufacturing Practice."