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The Specialists for Pectin - Herbstreith & Fox

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8<br />

Your texture requirements<br />

determine<br />

the choice of the<br />

suitable pectin.<br />

All Important: Degree of Esterification<br />

and Gelling Properties.<br />

<strong>Pectin</strong>s are divided into three groups<br />

on the basis of their different gelling<br />

properties.<br />

High Ester <strong>Pectin</strong>s<br />

(HM <strong>Pectin</strong>s)<br />

<strong>The</strong>se pectins have usually a more than<br />

50% share of esterified polygalac turonic<br />

acid units (DE°), thus practically no<br />

reaction with calcium ions oc-<br />

curs. <strong>The</strong> gel strength depends,<br />

among others, on acid<br />

content, type of pectin, concentration<br />

and soluble solids<br />

content, which generally has<br />

to be more than 55%.<br />

<strong>The</strong> degree of esterification correlates<br />

with the gel setting rate and gel texture<br />

under otherwise similar conditions. Very<br />

high esterified pectins jellify quicker resp.<br />

at higher temperatures and <strong>for</strong>m more<br />

elastic and brittle gel<br />

textures than less esterified<br />

pectins.<br />

This accurate correlation<br />

requires a very hom<br />

o gene ous inter- and<br />

intramolecular car boxyl group distribution,<br />

as is especially given in Classic Apple<br />

<strong>Pectin</strong>s from <strong>Herbstreith</strong> &<strong>Fox</strong>. Due<br />

to a blockwise distribution of carboxyl<br />

groups Classic Citrus <strong>Pectin</strong>s with the<br />

same degree of esterification will <strong>for</strong>m<br />

gels with a slightly higher setting temperature<br />

and a more elasticbrittle<br />

texture than Classic Apple <strong>Pectin</strong>s.<br />

<strong>The</strong> blockwise carboxyl groups distribution<br />

of high methylester pectins additionally<br />

provides advantages regarding<br />

protein stabilization in acidified milk<br />

drinks.<br />

Low Ester <strong>Pectin</strong>s<br />

(LM <strong>Pectin</strong>s)<br />

<strong>Pectin</strong>s with less than 50% share of esterified<br />

polygalacturonic acid units (DE°)<br />

can jellify with calcium ions. LM pectins<br />

thus do not only <strong>for</strong>m gels with sugar and<br />

acids, but at less soluble solids mainly<br />

with calcium ions. <strong>The</strong> resulting gel<br />

strength is determined<br />

by pectin concentration,<br />

type of pectin, soluble<br />

solids content, pH<br />

range and the concentration<br />

of buffer salts<br />

and calcium ions. A<br />

well matched balance between pectin<br />

and cal cium concen tra tion wi ll lead to an<br />

op timal texture.<br />

Exceeding the calcium optimum will produce<br />

a brittle gel with tendency towards<br />

syneresis (loss of water from the gel) or,<br />

in the end, to the <strong>for</strong>mation of calciumpectinate,<br />

the insoluble calcium salt of<br />

pectin.<br />

Since gel setting with LM pectins is also<br />

possible with a low soluble solids content<br />

and at a high pH-value, this opens up<br />

numerous application possibilities in<br />

dietetic and dairy products.<br />

Amidated <strong>Pectin</strong>s<br />

(HM- and LM Amidated<br />

<strong>Pectin</strong>s)<br />

In case of amidated pectins ammonia instead<br />

of acids is used <strong>for</strong> deesterification<br />

and with that part of the ester<br />

groups is replaced by amide groups. This<br />

process modifies the gelling properties in<br />

comparison to acid deesterified pectins.<br />

LM amidated pectins,<br />

just like non-amidated<br />

pectins, require calcium<br />

ions <strong>for</strong> gelling.<br />

<strong>The</strong>y will already set<br />

suf ficiently with only minor<br />

calcium amounts<br />

present. Furthermore, the gel setting<br />

temperature of ami dated pectins is less<br />

influenced by the calcium dosage.

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