the bead will be sufficiently thick once the appropriate quantity of pectin needed to form a gel with
calcium is added, that it is unlikely that the beads centre will “explode” in the mouth like with beads
made from a solution containing a similar quantity of alginate.
Carrageenans are also gelling agenst that are extracted from red seaweeds. It is composed of long
strands made up of the following subunit:
How it works
Like the other agents discussed above, it is used in the kitchen to form gels – mainly from milk based
preparations. This is because carrageenans form very effective gels in contact with the proteins and
calcium ions in milk and cream, so strong gels can be formed using a very small amount of carrageen,
which is why it is popular in industry.
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To make a milk based gel, 0.5 % by weight of carrageenans is added top a flavored milk based
preparation (for example, milk flavored with vanilla and chili, coffee flavored milk – carrageenans can
be used in the presence of both salt and sugar without affecting subsequent gel formation), and the
mixture is heated to about 70°C, stirring constantly, to dissolve and disperse the carrageen. The
mixture should be stirred rather than whisked, because whisking milk while heating it, will incorporate
air bubbles, which may be subsequently set in the gel.
In a similar fashion to agar agar, once the milk carrageenans mixture is removed from the heat, the
long carrageenans molecules will stop moving around so quickly, and will form a network with the milk
proteins and calcium ions, trapping the free water and producing a gel.
Carrageenans based gels are fairly elastic, and display the property of thixotropy – this means that if
the gel is broken up by agitating it, it will reform a gel once agitation is stopped (for iota-carrageenan).
Also carrageenans based gels can be heated to approximately 60°C before they will melt.
Carrageenans are very useful in industry, where the small concentration required to form a gel is