Alginic acid INS No. 400
Prepared at the 49th JECFA (1997) ,published in FNP 52 Add 5 (1997) superseding specifications prepared at the 44th JECFA (1995), published in FNP 52 Add 3 (1995). Metals and arsenic specifications revised at the 49th JECFA (1997). An ADI 'not specified' was established at the 39th
JECFA (1992)
SYNONYMS INS No. 400
DEFINITION
Alginic acid is a naturally occurring hydrophilic colloidal polysaccharide obtained from the various species of brown seaweed (Phaeophyceae). It is
a linear copolymer consisting mainly of residues of ß-1,4-linked Dmannuronic acid and a-1,4-linked L-glucuronic acid. These monomers are often arranged in homopolymeric blocks separated by regions approximating an alternating sequence of the two acid monomers.
C.A.S. number 9005-32-7
Chemical formula (C6H8O6)n
Structural formula Structural formula from Phillips, Wedlock and Williams: Gums and Stabilizers for the Food Industry 5 (1990) by permission of Oxford University Press.
The number and sequence of the Mannuronate and Glucuronate residues shown above vary in the naturally occurring alginate. The associated water molecules are not shown.
Formula weight Structural unit: 176.13 (theoretical), 200 (actual average) Macromolecule : 10,000 - 600,000 (typical average)
Assay Yields, on the dried basis not less than 20.0% and not more than 23.0% of carbon dioxide (CO2), equivalent to not less than 91.0% and not more than 104.5% of alginic acid (C6H8O6)n .
DESCRIPTION White to yellowish brown filamentous, grainy, granular or powdered forms
FUNCTIONAL USES Stabilizer, thickener, gelling agent, emulsifier
