It is widely known the first name of carrageenan as Irish Moss, cause the early Irish used to boil milk with seaweeds (moss in Gaelic) to form a pudding dessert.

The carrageenans extracted from red seaweeds are not assimilated by the human body, providing only bulk and no nutrition and are, from a nutritional point of view, infact classified as soluble fiber; nevertheless carrageenans provide outstanding divers functional properties, which can be used to control moisture and texture and to stabilize a variety of food processed products.


The red seaweeds produce extracts that compose a big family of hydrocolloids, including Agar, Furcellaran and three types of Carrageenans (Kappa, Iota and Lambda) they all have a galactose backbone but differentiate by the position and the amount of ester sulphate groups and anhydro-galactose, as resuls the gels of Agar are very brittle, less the Kappa and Iota Carrageenans gels, and non gelling are the Lambda Carrageenan ones.


There are a number of different red seaweeds depending on the geographical condition where they are growing:

  • from Chodrus Crispus, a seaweed growing in cold waters, Kappa and Lambda are obtained;
  • from Euchema, the first seaweed cultivated, which is farmed in warm shallow waters, derive Kappa and Iota;
  • Gigartina that is a seaweed born in cold water, makes Kappa and Lambda.


As mentioned Carrageenans has several application in food and not only, because within the sub families of this natural hydrocolloid, a very broad range of textures can be developed by using their different properties, leveraging also the sinergysm with some other hydrocolloids (Konjac flour, Locust Bean Gum) and with milk proteins too.

Kappa Carrageenans form a gel in the presence of potassium ions, this property is largely exploited in meat, in dessert gel and in cake glazes;

Iota and Lambda are only little affected by potassium content; often in dairy beverages applications a combination of Kappa and Lambda is used for suspension and creaminess.


All Carrageenans are soluble in hot water, except Lambda which is soluble in cold water as well, but with the addition of sodium also Iota and Kappa can become cold soluble.