CALCIUM PROPIONATE

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 Addendum 3 (1995). These specifications were reviewed and maintained at the 51 st JECFA (1998) and republished in FNP 52 Add 6 (1998). ADI "not limited"established at the 17th JECFA in 1973.

SYNONYMS

Calcium propanoate, INS No. 282

DEFINITION

Chemical names

Calcium propionate

C.A.S. number

4075-81-4

Chemical formula

C₆H₁₀CaO₄

Structural formula

Formula weight

186.22

Assay

Not less than 98.0% on the dried basis

DESCRIPTION

White crystals, powder or granules with not more than a faint odour of propionic acid

FUNCTIONAL USES

Preservative, antimould and antirope agent

CHARACTERISTICS

IDENTIFICATION

Solubility

Freely soluble in water, soluble in ethanol

Test for calcium

Passes test

Test for propionate

Warm the sample with sulfuric acid. The propionic acid evolved may be recognized by its odour.

Test for alkali salt of organic acid

Ignite the sample at a relatively low temperature. The alkaline organic acid residue effervesces with acid.

PURITY

Loss on drying

Not more than 4% (105^o, 2 h)

pH

7.5 - 10.5 (1 in 10 soln)

Water insoluble matter

Not more than 0.3%

Weigh 5 g of the sample to the nearest mg, transfer into a 100-ml beaker and add 50 ml of water. Stir until all the sample appears to be completely dissolved. Filter through a Gooch crucible, tared to an accuracy of ±0.2 mg. Rinse the beaker with 20 ml of water. Dry the crucible with its contents in a 60^o-oven to constant weight. Cool in a desiccator, weigh, and calculate as percentage.

Fluoride

Not more than 30 mg/kg

Weigh 5 g of the sample to the nearest mg and proceed as directed in the Limit Test (Method I or III)

Iron

Not more than 50 mg/kg

Test 0.5 g of the sample as described in the Limit Test using 2.5 ml of Iron Standard Solution (25 µg) in the control

Lead

Not more than 5 mg/kg

Prepare a sample solution as directed for organic compounds in the Limit Test, using 5 µg of lead ion (Pb) in the control

METHOD OF ASSAY

Dissolve in a beaker 2.5 g of the sample, weighed to the nearest mg, in 5 ml of hot dilute hydrochloric acid TS. Cool, transfer to a 250-ml volumetric flask, dilute to volume with water, and mix. Transfer 50 ml of the solution to a 400-ml beaker, add 100 ml of water, 25 ml of sodium hydroxide TS, 40 mg of murexide indicator preparation and 3 ml of naphthol green TS. An alternative indicator is hydroxynaphthol blue, of which 0.25 g is used. In this case the naphthol green TS is omitted. Titrate with 0.05 M disodium ethylenediaminetetraacetate until the solution is deep blue in colour. Each ml of 0.05 M disodium ethylenediaminetetraacetate is equivalent to 9.311 mg of C₆H₁₀CaO₄.