|
Prepared at the 41st JECFA (1993), published in FNP 52 Add 2 (1993) superseding specifications prepared at the 39th JECFA (1992), published in FNP 52 Add 1 (1992) |
|
SYNONYMS |
INS No. 404 |
DEFINITION |
Calcium salt of alginic acid. |
C.A.S. number |
9005-35-0 |
Chemical formula |
(C6 H7 Ca1/2 O6)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.
|
Formula weight |
Structural unit: 195.16 (theoretical), 219 (actual average) Macromolecule: 32,000 - 250,000 |
Assay |
Not less than 18.0% and not more than 21.0% of carbon dioxide (CO2), equivalent to not less than 89.6% and not more than 104.5% of calcium alginate (C6H7Ca1/2 O6)n. |
DESCRIPTION |
White to yellowish brown filamentous, grainy, granular and powdered forms |
FUNCTIONAL USES |
Stabilizer and thickener. |
CHARACTERISTICS | |
IDENTIFICATION | |
Solubility |
Insoluble in water and ether; slightly soluble in ethanol; slowly soluble in solutions of sodium polyphosphate, sodium carbonate, and substances that combine with the calcium. |
Precipitate formation with calcium chloride |
To a 0.5% solution of the sample in sodium hydroxide TS add one-fifth of its volume of a 2.5% solution of calcium chloride. A voluminous, gelatinous precipitate is formed. This test distinguishes ammonium alginate from gum arabic, sodium carboxymethyl cellulose, carrageenan, gelatin, gum ghatti, karaya gum, carob bean gum, methyl cellulose and tragacanth gum. |
Precipitate formation with ammonium sulfate |
To a 0.5% solution of the sample in sodium hydroxide TS add one-half of its volume of a saturated solution of ammonium sulfate. No precipitate is formed. This test distinguishes ammonium alginate from agar, sodium carboxymethyl cellulose, carrageenan, de-esterified pectin, gelatin, carob bean gum, methyl cellulose and starch. |
Colour reaction |
Passes test Moisten 1-5 mg of the sample with water, and add 1 ml of acid ferric sulfate TS. Within 5 min, a cherry-red colour develops that finally becomes deep purple. |
Test for calcium |
Passes test Dissolve the sulfated ash of the sample in dilute acetic acid TS and filter. Treat the filtrate with ammonium oxalate TS. The white precipitate formed is soluble in hydrochloric acid. |
PURITY | |
Loss on drying |
Not more than 15% (105o, 4 h) |
Total ash |
Not less than 13% and not more than 24% on the dried basis |
Arsenic |
Not more than 3 % mg/kg (Method II) |
Lead |
Not more than 10 mg/kg Prepare a sample solution as directed for organic compounds in the Limit Test, using 10 µg of lead ion (Pb) in the control |
Heavy metals |
Not more than 40 mg/kg Test 0.5 g of the sample as directed under the Limit Test (Method II) |
METHOD OF ASSAY |
Proceed as directed under Carbon Dioxide Determination by Decarboxylation. Each ml of 0.25 N sodium hydroxide consumed is equivalent to 5.5 mg of carbon dioxide (CO2) or 27.38 mg of calcium alginate (equivalent weight 219) |