Sodium propionate

Description

Sodium propanoate or sodium propionate is the sodium salt of propionic acid which has the chemical formula Na(C₂H₅COO).

Chemical properties

Colourless crystals or, white or almost white powder, slightly hygroscopic.

The Uses of Sodium propionate

Sodium Propionate is an antimicrobial agent that is the sodium salt of propionic acid. it occurs as colorless, transparent crystals or a gran- ular crystalline powder. it is odorless or has a faint acetic–butyric acid odor, and is deliquescent. it is prepared by neutralizing propionic acid with sodium hydroxide. it is used in baked goods; nonalcoholic beverages; cheeses; confections and frostings; gelatins, puddings, and fillings; jams and jellies; meat products; and soft candy.

The Uses of Sodium propionate

Fungicide, mold preventative.

The Uses of Sodium propionate

It is used as a food preservative and is represented by the food labeling E number E281 in Europe; it is used primarily as a mold inhibitor in bakery products. It is approved for use as a food additive in the EU, USA and Australia and New Zealand ( where it is listed by its INS number 281 ) .

Definition

ChEBI: An organic sodium salt comprising equal numbers of sodium and propionate ions.

Reactions

It is produced by the reaction of propionic acid and sodium carbonate or sodium hydroxide.

Flammability and Explosibility

Not classified

Biological Activity

If sodium propionate is ingested or applied topically in an acid media, it becomes propionic acid. It oxidizes fatty acids, lowers pH values, and facilitates the citric acid cycle through interaction with coenzyme A. There has been evidence of heightened production of insulin in cows and sheep; the insulin later settles to an overall lower level. Propionic acid inhibits 14CO2 production from palmitate in both control and methylmalonic fibroblasts; propionic acid also inhibited ureagenesis in rat liver slices. These findings may explain the fatty degeneration of the liver and hyperammonemia in propionic and methylmalonic acidemia. Propionic acidemia is an autosomal recessive disorder caused by a defect of propionyl–coenzyme A carboxylase. The main clinical findings are vomiting, lethargy, hypotonia, and metabolic ketoacidosis, and early clinical onset occurs during the neonatal period in ～80% of the patients.

Biochem/physiol Actions

Sodium propionate has an ability to prevent ketosis in dairy cattle.

Safety Profile

Moderately toxic by skin contact and subcutaneous routes. Mildly toxic by unspecified routes. An allergen. When heated to decomposition it emits toxic fumes of Na2O.

Structure

Anhydrous sodium propionate is a polymeric structure, featuring trigonal prismatic Na+ centers bonded to six oxygen ligands provided by the carboxylates.

Preparation

Sodium propanoate is produced by the reaction of propionic acid and sodium carbonate or sodium hydroxide.

Purification Methods

Recrystallise it from H2O (solubility 10%) and dry by heating at 100o for 4hours. The solubility of the anhydrous salt in MeOH is 13% at 15o and 13.77% at 68o. It is insoluble in *C6H6 and Me2CO. [Henstock J Chem Soc 1341 1934, Beilstein 2 IV 701.]

Mechanism of food preservation

Sodium propionate at levels of 0.1–5.0% delays the growth of Staphylococcus aureus, Sarcina lutea, Proteus vulgaris, Lactobacillus plantarum, Torula and Saccharomyces ellipsoideus by 5 days. The bacteriostatic action of sodium propionate can be overcome by addition of small amounts of β-alanine for Escherichia coli, but not for other organisms such as Aspergillus clavatus, Bacillus subtilis, Pseudomonas spp. and Trichophyton mentagrophytes. It is believed that the inhibitory action of sodium propionate against E. coli may be due to interference with β-alanine synthesis.