Carrageenan (sometimes spelt ‘carrageenin’) is a family of linear sulphated polysaccarides; a type of large molecule of carbohydrate; which is extracted from red seaweed. It is used as an additive in many food products due to its gelling, thickening, stabilising and emulsifying properties.
At its most basic, it is produced by exposing the seaweed to hot water, then proceeding to evaporate the water leaving just the gel, although, suffice to say, modern production processes are more complicated. Here the harvested seaweed is dried, sifted and washed before being exposed to a hot alkali solution. Cellulose is then removed from the resulting mixture via centrifugation and filtration, before evaporating the alkali solution. The gel is then dried and powdered for use.
Carrageenan is usually divided into three classes for commercial use, which are dependent on the degree of sulphation and that have differing properties: kappa, which has one sulphate per disaccharide and forms a rigid gel in the presence of potassium; iota, which has two sulphates and forms a soft gel in the presence of calcium; and lambda, which has three sulphates and does not gel at all. As you may surmise from the naming scheme, there are many other types of carrageenan, however these are not typically used for commercial applications.
The properties of carrageenan, or rather of Chondrus Crispus, the earliest known seaweed in which it was noted, have been known since at least 1810, when it was reportedly given in Ireland as recommended cure for respiratory ailments; though the FAO alleged in 1965 that its use could be traced back to about the 14th century (this same article however also claims that this was in ‘Carragheen County’ on Ireland’s southern coast; no such county appears to be reported as having existed in Irish history outside of this article and those citing it), and Wikipedia even further back (it however fails to cite a source); a recipe for carrageenan gelatin can reportedly be found in the Encyclopédie, published between 1751 and 1772. In 1819, botanist Dawson Turner described that the plant would "melt on boiling and afterwards harden into a gelatine, which I do not despair of seeing hereafter employed to useful purposes, though I have hitherto failed in my efforts to render it of service". With the Irish diaspora, its usage came to spread to other countries as well. The gelling agent found in the seaweed was reportedly first isolated in 1837, and first purified by alcohol precipitation in 1871. Popularity of this carrageenan extracted rocketed with the Second World War, when trade embargoes with Japan cut off the supply of agar, a similarly gelatinous seaweed extract.
In modern times, carrageenan is subject to some controversy regarding its effects on health, in particular that of the gastrointestinal tract and especially the bowels. These effects are alleged to include malignancy and cancer. Studies regarding this are typically inconclusive, with results varying wildly. Things are complicated further by the most famous and frequently cited of modern studies being called into question due to not taking into account relative body weight (that is, the rats in the study were fed the same amount a human would consume rather than a similar amount proportional to their body weight). Older studies are reportedly based on ‘degraded’ carrageenan, a part of the low-molecular weight section of carrageenan’s molecular backbone, which has since been redesignated ‘poligeenan’ by the scientific community in order to differentiate it; this is officially defined as having between 10,000 and 20,000 da (Daltons). This in fact is deemed by studies as having potential severe health risks, and is ostensibly not used as a food additive. The European Scientific Committee on Food recommends that a fragment of food-grade carrageenan contains no more than 5% with less than 50,000 da in a bid to keep presence of poligeenan low. In practice, the figure is closer to 8%. The proportion of poligeenan in this is unknown, so you may wish to take caution. The Joint FAO/WHO Expert Committee on Food Additives (JECFA)’s findings have, on multiple occasions, suggested that at the typical estimated levels of human intake, carrageenan is safe to consume, however care is never the less advised. In particular, they advise that it is not used in infant formula, due to it being an infant’s presumed sole dietary intake and concerns about its absorption by the immature gut; while evidence suggests that a mature gut will not absorb carrageenan, current lack of studies on its effect on a not-fully-developed gut are a cause for concern for the committee. As a result, the EU forbids its use in baby formula, although the US still allows it.
Moo Free does not use carrageenan in its products.
- FAO: Training Manual on Gracilaria Culture and Seaweed Processing in China - Chapter III: Properties, Manufacture, and Application of Seaweed Polysaccharides - Agar, Carrageenan and Algin
- Seaweed.ie: Carrageenans
- Wikipedia: Carrageenan (Rev.2014/01/27)
- International Programme on Chemical Safety: 934. Carrageenan (WHO Food Additives Series 42)
- European Scientific Committee on Food: Opinion on Carrageenan, adopted 5 March 2003 (PDF)