Benzoate, sodium

Sodium benzoate as a food preservative is generally limited to products that are naturally acidic and is more effective in food systems where the pH 4. It is mainly used as an antimycotic agent and most yeasts and molds are inhibited by a concentration of 0.05-0.1% (Barbosa-Canovas et al., 2003). Benzoates and parabenzoates are used primarily in fruit juices, chocolate syrup, candied fruit peel, pie fillings, pickled vegetables, relishes, horseradish, and cheese. Sodium benzoate produces benzoic acid once it is dissolved in water (Marsili, Sobrero, and Goicoechea, 2003). 

BP Sodium benzoate JP Sodium benzoate PhEur Natrii benzoas USPNF Sodium benzoate 

Benzoic acid sodium salt benzoate of soda E211 natrium benzoicum sobenate sodii benzoas sodium benzoic acid. 

Sodium benzoate is used primarily as an antimicrobial preservative in cosmetics, foods, and pharmaceuticals. It is used in concentrations of 0.02-0.5% in oral medicines, 0.5% in parenteral products, and 0.1-0.5% in cosmetics. The usefulness of sodium benzoate as a preservative is limited by its effectiveness over a narrow pH range see Section 10. 

Sodium benzoate is used in preference to benzoic acid in some circumstances, owing to its greater solubility. However, in some applications it may impart an unpleasant flavor to a product. Sodium benzoate has also been used as a tablet lubricant at 2-5% w/w concentrations. Solutions of sodium benzoate have also been administered, orally or intravenously, in order to determine liver function. 

Sodium benzoate occurs as a white granular or crystalline, slightly hygroscopic powder. It is odorless, or with faint odor of benzoin and has an unpleasant sweet and saline taste. 

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Much of the benzoic acid produced is converted to sodium benzoate, which is used as a food preservative (as is the acid) and a corrosion inhibi tor. Other important uses of the acid are in the manufacture of alkyd resins, plasticizers, caprolactam, dyestuffs and pharmaceuticals. 

Sodium benzoate,—Burns with great difficulty, and after prolonged heating leaves a white infusible residue of NajCOj. Scrape this residue into a test-tube, and test for carbonate in the usual way. Typical of alkali salts of carboxylic acids. 

Sodium acetate CH3COONa Sodium succinate (CHaCOONa), Sodium benzoate CeHjCOONa Sodium formate HCOONa i Sodium oxalate fCOONa) J Sodium salicylate HOCeH COONa... 

In general, benzoylation of aromatic amines finds less application than acetylation in preparative work, but the process is often employed for the identification and characterisation of aromatic amines (and also of hydroxy compounds). Benzoyl chloride (Section IV, 185) is the reagent commonly used. This reagent is so slowly hydrolysed by water that benzoylation can be carried out in an aqueous medium. In the Schotten-Baumann method of benzoylation the amino compound or its salt is dissolved or suspended in a slight excess of 8-15 per cent, sodium hydroxide solution, a small excess (about 10-15 per cent, more than the theoretical quantity) of benzoyl chloride is then added and the mixture vigorously shaken in a stoppered vessel (or else the mixture is stirred mechanically). Benzoylation proceeds smoothly and the sparingly soluble benzoyl derivative usually separates as a solid. The sodium hydroxide hydrolyses the excess of benzoyl chloride, yielding sodium benzoate and sodium chloride, which remain in solution ... 

Salts. Sodium benzoate Sodium benzenesulphonate Aniline hydrochloride Methylamine hydrochloride. 

In one manufacturing process, aluminum chloride is treated with a solution containing sodium carbonate and sodium bicarbonate. The product of this reaction is mixed with the precipitate obtained by reaction of a solution of aluminum chloride and ammonia. The mixed magma is dialyzed, the product mixed with glycerol (qv), sodium benzoate is added, and the mixture is then passed through a coUoid mill. 

Aqueous sodium thiosulfate solutions ate neutral. Under neutral or slightly acidic conditions, decomposition produces sulfite and sulfur. In the presence of air, alkaline solutions decompose to sulfate and sulfide. Dilute solutions can be stabilized by small amounts of sodium sulfite, sodium carbonate, or caustic, and by storage at low temperatures away from air and light. Oxidation is inhibited by Hgl2 (10 Ppm) amyl alcohol (1%), chloroform (0.1%), borax (0.05%), or sodium benzoate (0.1%). 

Benzoic Acid. Ben2oic acid is manufactured from toluene by oxidation in the liquid phase using air and a cobalt catalyst. Typical conditions are 308—790 kPa (30—100 psi) and 130—160°C. The cmde product is purified by distillation, crystallization, or both. Yields are generally >90 mol%, and product purity is generally >99%. Kalama Chemical Company, the largest producer, converts about half of its production to phenol, but most producers consider the most economic process for phenol to be peroxidation of cumene. Other uses of benzoic acid are for the manufacture of benzoyl chloride, of plasticizers such as butyl benzoate, and of sodium benzoate for use in preservatives. In Italy, Snia Viscosa uses benzoic acid as raw material for the production of caprolactam, and subsequendy nylon-6, by the sequence shown below. 

In the early 1900s several food inspection decisions regarding the use of benzoic acid and sodium benzoate were issued, the latter based upon... 

Sodium and Potassium Benzoate. These salts are available in grades meeting the specifications of the 25ationalVormulary (18) and the Vood Chemicals Codex (19) (Table 7). Sodium benzoate [532-32-1] is produced by the neutralization of benzoic acid with caustic soda and/or soda ash. The resulting solution is then treated to remove trace impurities as weU as color bodies and then dried in steam heated double dmm dryers. The product removed from the dryers is light and fluffy and in order to reduce shipping and storage space the sodium benzoate is normally compacted. It is then milled and classified into various product forms, the names of which often bear Httle relationship to the actual form of the product. 

Potassium benzoate [582-25-2] is produced by neutralizing benzoic acid with caustic potash. The resulting solution is processed in a fashion nearly identical to that of sodium benzoate. Product forms are also similar. 

Sodium and potassium benzoate are employed in a wide range of preservative appHcations because they provide an effective combination of antimicrobial action, low cost, and safety. Although sodium and potassium benzoate are the preservatives offered in the marketplace, the actual active ingredient being sold is free (or undissociated) benzoic acid. The benzoate ion has essentially no antimicrobial properties. Since it is the undissociated (free) benzoic acid that provides the antimicrobial action, sodium benzoate and potassium benzoate are recommended for use in appHcation areas where the pH is at 4.5 or lower (Table 8). 

Sodium benzoate is also finding increasing appHcation as a corrosion inhibitor. It is incorporated into paper wrapping materials for the prevention of mst or corrosion in the production of such diverse items as razor blades, engine parts, bearings, etc. It is also used in the automotive industry as a corrosion inhibitor in engine cooling systems (at 1.5%), mainly in Europe and Japan. Unlike in its appHcation as a preservative where free benzoic acid is required to provide antimicrobial action, it appears to be the benzoate ion that provides the corrosion protection. 

Sodium hen ate [532-32-1], C H COONa, is highly soluble in water (61.2 g dissolve in 100 g of water at 25°C) and somewhat soluble in ethyl alcohol, glycerol, and methanol. A 25% aqueous solution of sodium benzoate exhibits a pH of 7.5—8. 

Ben /ben ate [120-51-4] CgH COOCH2CgH, mp, 21°C, cff , 1.118 bp, 323—324°C at 101.3 kPa , 1.5681. This is a colorless, oily liquid with a faiat, pleasant aromatic odor and a sharp, burning taste. It occurs naturally iu Pern and Tolu balsams, is spariugly volatile with steam, and is iusoluble iu water. Benzyl benzoate is prepared commercially by the direct esterification of benzoic acid and benzyl alcohol or by reaction of benzyl chloride and sodium benzoate. The pleasant odor of benzyl benzoate, like other benzoic esters, has long been utilized iu the perfume iadustry, where it is employed as a solvent for synthetic musks and as a fixative. It has also been used iu confectionery and chewing gum flavors. 

Esterification. Chlorohydrins can react with salts of carboxyUc acids to form esters. For example, 2-hydroxyethyl benzoate [134-11-2] was prepared ia 92% yield by heating sodium benzoate [532-32-1] with an excess of ethylene chlorohydrin ia the presence of a small amount of diethylamine... 

Federal name Sodium benzoate, 1% Ascorbic acid, 1% Sulfur dioxide, 25 ppm Sulfur dioxide, 250 ppm... 

For information on ionization (pK) see Chapter 1, p. 7, and Chapter 4, p. 80. In order to avoid repetition, the literature (or predicted) pK values of anionic and/or cationic species are usually reported at least once, and in several cases is entered for the free acid or free base, e.g. Na2S04 will have a pK value for Na" " at the entry for NaOH and the pK values for S04 at the entries for H2SO4. When the pK values of the organic counter-ions are not given in this Chapter, as in case of sodium benzoate, the reader is referred to the value(s) in Chapter 4, e.g. of benzoic acid. ... 

Sodium benzoate [532-32-1] M 144.1. Crystd from EtOH (12mL/g). 

The Canni2zaro reaction is a disproportionation that takes place in strongly basic solution and converts benzaldehyde to benzyl alcohol and sodium benzoate. 

When the reaction is carried out in H2 0, both the benzyl alcohol and sodium benzoate contain... 

Sodium thenoate is bromodecarboxylated in low yield, slower than sodium anisate, but more rapidly than sodium benzoate. However, the Hunsdiecker reaction with silver salts has been used preparatively for the synthesis of 2,3-dibromo-4-nitrothiophene from 3-bromo-4-nitro-2-thiophenecarboxylic acid. ... 

A mixture of 1,9 grams of 2-hydroxy-3-carboxypropiophenone, 5,0 grams of sodium benzoate and 20,0 grams of benzoic anhydride is heated at 180° to 190°C for 6 hours, A solution of 15,0 grams of potassium hydroxide in 50 ml of ethanol and 20 ml of water is added and refluxed for 1 hour. The mixture is evaporated and the residue after addition of water yields 3-methylflavone-8-carboxylic acid. 

In 20 liters of human urine is dissolved 1,200 grams of sodium benzoate (6% weight by volume). The solution is acidified with aqueous hydrochloric acid (assay about 7.5% HCI) to a pH of 4.5 resulting in a heavy precipitation. This requires 10% of the original urine volume, or about 2 liters of aqueous hydrochloric acid. The suspension is stirred 20 minutes and is then allowed to stand for about 30 minutes. The mixture so obtained is filtered on a Buchner funnel that has been prepared with a precoat of benzoic acid crystals over filter paper. The filter cake is washed with a saturated benzoic acid solution, then sucked dry. The benzoic acid cake with the adsorbed urokinase weighs 2,060 grams. 

The filter cake is stirred with 3.1 liters of acetone. The volume of acetone used is about 1.5 times the weight of the cake resulting in about a 65% acetone concentration. The benzoic acid dissolves in the acetone and the urokinase flocculates out. Sodium benzoate, about 1% of the weight of the cake, or 21 grams, is added to speed up the formation of the precipitate. The suspension of crude urokinase in acetone Is filtered on a Buchner funnel using filter paper precoated with a diatomaceous silica product (Celite 505). The precipitate is washed with acetone until the filtrate is water clear. The precipitate is then washed with ether and air dried. The yield of powder so obtained is 2.3 grams. 

Soldered brass seldom gives trouble. In radiators, antifreeze solutions have been alleged to cause corrosion, possibly because materials such as ethylene glycol sometimes detach protective deposits. Sodium nitrite, valuable as a corrosion inhibitor for other metals in a radiator, tends to attack solders, but sodium benzoate is safe and, in addition, protects the soldered joint against the action of nitrites. In an investigation of other inhibitors in ethylene glycol solutions, 1% borax, either alone or in combination with 0-1% mercaptobenzothiazole, appeared to be satisfactory. 

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