There is something you should know about Sodium benzoate.
2018-09-20 14:52:02
Introduction:
Sodium benzoate is a substance which has the chemical formula NaC7H5O2. It is a widely used food preservative, with an E number of E211. It is the sodium salt of benzoic acid and exists in this form when dissolved in water. It can be produced by reacting sodium hydroxide with benzoic acid.
Production:
Sodium benzoate is produced by the neutralization of benzoic acid,which is itself produced commercially by partial oxidation of toluene with oxygen.
Natural occurrence:
Sodium benzoate occurs naturally, along with benzoic acid and its esters, in many foods.Fruits and vegetables can be rich sources, particularly berries such as cranberry and bilberry, other sources include seafood such as prawns, and dairy products like milk, cheese and yogurt.
Uses:
1.Preservative
Sodium benzoate is a preservative, with the E number E211. It is most widely used in acidic foods such as salad dressings (i.e. acetic acid in vinegar), carbonated drinks (carbonic acid), jams and fruit juices (citric acid), pickles (acetic acid), condiments and frogurt toppings. It is also used as a preservative in medicines and cosmetics.Under these conditions it is converted into benzoic acid (E210), which is bacteriostatic and fungistatic. Benzoic acid is generally not used directly due to its poor water solubility. Concentration as a food preservative is limited by the FDA in the U.S. to 0.1% by weight.Sodium benzoate is also allowed as an animal food additive at up to 0.1%, according to AFCO's official publication.Sodium benzoate has been replaced by potassium sorbate in the majority of soft drinks in the United Kingdom.
2.Pharmaceutical applications
Sodium benzoate is used as a treatment for urea cycle disorders due to its ability to bind amino acids.This leads to excretion of these amino acids and a decrease in ammonia levels. Recent research shows that sodium benzoate may be beneficial as an add-on therapy (1 gram/day) in schizophrenia.Total Positive and Negative Syndrome Scale scores dropped by 21% compared to placebo.
Sodium benzoate, along with phenylbutyrate, is used to treat hyperammonemia.
3.Other uses
Sodium benzoate is also used in fireworks as a fuel in whistle mix, a powder that emits a whistling noise when compressed into a tube and ignited.
Mechanism of food preservation:
The mechanism starts with the absorption of benzoic acid into the cell. If the intracellular pH falls to 5 or lower, the anaerobic fermentation of glucose through phosphofructokinase decreases sharply, which inhibits the growth and survival of microorganisms that cause food spoilage.
Health and safety:
In the United States, sodium benzoate is designated as generally recognized as safe (GRAS) by the Food and Drug Administration. The International Programme on Chemical Safety found no adverse effects in humans at doses of 647–825 mg/kg of body weight per day.
Cats have a significantly lower tolerance against benzoic acid and its salts than rats and mice. The human body rapidly clears sodium benzoate by combining it with glycine to form hippuric acid which is then excreted. The metabolic pathway for this begins with the conversion of benzoate by butyrate-CoA ligase into an intermediate product, benzoyl-CoA, which is then metabolized by glycine N-acyltransferase into hippuric acid.
Association with benzene in soft drinks:
In combination with ascorbic acid (vitamin C, E300), sodium benzoate and potassium benzoate may form benzene, a known carcinogen. When tested by the FDA, most beverages that contained both ascorbic acid and benzoate had benzene levels that were below those considered dangerous for consumption by the World Health Organization (5 ppb). Most of the beverages that tested higher have been reformulated and subsequently tested below the safety limit. Heat, light and shelf life can increase the rate at which benzene is formed.