Properties of Carrageenan explained

Posted in Food

Properties of Carrageenan explained

They are food additives used in the food industry as well as other industries as stabilizing and thickening agents. Carrageenan is huge, extremely adaptable molecules that coil forming spiral structures. This makes them the capability to shape a wide range of gels even at room temperature. They are quite popular in the food industry as well as other industries for its stabilizing and thickening properties.

All Carrageenans are polysaccharides with high molecular weight formed with repeated units of galactose and 3,6 anhydrogalactose, both non-sulfated and sulfated. The units are attached by exchanging α-1,3 and β-1,4 glycosidic linkages.

The three major classes of this food additive (Carrageenan)are

Iota– It forms gels in existence of calcium ions. It is made from  Eucheuma denticulatum.
Kappa- It forms rigid and strong gels in existence of potassium ions. It responds to dairy proteins  and is produced from Kappaphycus alvarezii.

Lambda– It does not gel and it is used in thickening of dairy products.

The basic difference that affects the properties of Iota, Kappa and Lambda are based on the placement of ester sulfate groups upon galactose unit repetition. The solubility temperature of the ingredient is lower in case the ester sulfate levels are high.  In such cases it produces gels with lower strengths or leads to gel obstructions.

Many species of red algal produce various types of carrageenans during their growing stage. For example the genus Gigartina generates kappa carragenans during the gametophytic phase and lambda during the sporophytic phase.

All are easily soluble in water, but when it comes to cold water only lambda are easily soluble in cold water. When it (carrageenan) is used in food products, it has EU additive number, E- number when it exists as processed eucheuma seaweed. Technically it is considered as a dietary fibre.

In Ireland and Scotland it is known with different local names and native names too.