CARRAGEENAN
Prepared at the 68th JECFA (2007) and published in FAO JECFA Monographs 4 (2007), superseding specifications prepared at the 57th JECFA (2001), published in the Combined Compendium of Food Additive Specifications, FAO JECFA Monographs 1 (2005). A group ADI “not
specified” for carrageenan and processed Eucheuma seaweed was established at the 57th JECFA (2001).
SYNONYMS Irish moss gelose (from Chondrus spp.); Eucheuman (from Eucheuma spp.); Iridophycan (from Iridaea spp.); Hypnean (from Hypnea spp.); Furcellaran or Danish agar (from Furcellaria fastigiata); INS No. 407.
DEFINITION A substance with hydrocolloid properties obtained from certain members of the class Rhodophyceae (red seaweeds).
The principal commercial sources of carrageenans are the following families and genera of the class of Rhodophyceae:
Furcellariacaea such as Furcellaria
Gigartinaceae such as Chondrus, Gigartina, Iridaea
Hypnaeceae such as Hypnea
Phyllophoraceae such as Phyllophora, Gynmogongrus, Ahnfeltia
Solieriaceae such as Eucheuma, Anatheca, Meristotheca.
Carrageenan is a hydrocolloid consisting mainly of the ammonium, calcium, magnesium, potassium and sodium sulfate esters of galactose
and 3,6-anhydrogalactose polysaccharides. These hexoses are alternately linked α-1,3 and β-1,4 in the copolymer. The relative proportions of cations existing in carrageenan may be changed during processing to the extent that one may become predominant.
The prevalent polysaccharides in carrageenan are designated as kappa-, iota-, and lambda-carrageenan. Kappa-carrageenan is mostly the
alternating polymer of D-galactose-4-sulfate and 3,6-anhydro-D-galactose; iota-carrageenan is similar, except that the 3,6-anhydrogalactose is
sulfated at carbon 2. Between kappa-carrageenan and iota-carrageenan there is a continuum of intermediate compositions differing in degree of
sulfation at carbon 2. In lambda-carrageenan, the alternating monomeric units are mostly D-galactose-2-sulfate (1,3-linked) and D-galactose-2,6-
disulfate (1,4-linked).
Carrageenan is obtained by extraction from seaweed into water or aqueous dilute alkali. Carrageenan may be recovered by alcohol precipitation, by
drum drying, or by precipitation in aqueous potassium chloride and subsequent freezing. The alcohols used during recovery and purification are restricted to methanol, ethanol, and isopropanol.
Articles of commerce may include sugars for standardization purposes, salts to obtain specific gelling or thickening characteristics, or emulsifiers carried over from drum drying processes.
C.A.S. number 9000-07-1
DESCRIPTION Yellowish or tan to white, coarse to fine powder that is practically odourless.
FUNCTIONAL USES Thickener, gelling agent, stabilizer, emulsifier
