Potassium benzoate
Encyclopedia
Potassium benzoate the potassium salt of benzoic acid
, is a food preservative
that inhibits the growth of mold
, yeast
and some bacteria. It works best in low-pH
products, below 4.5, where it exists as benzoic acid.
Acidic foods and beverages such as fruit juice (citric acid
), sparkling drinks (carbonic acid
), soft drink
s (phosphoric acid
), and pickles
(vinegar
) may be preserved with potassium benzoate. It is approved for use in most countries including Canada
, the U.S.
, and the EU, where it is designated by the E number
E212. In the EU, it is not recommended for consumption by children.
Potassium benzoate is also used as the whistle in many fireworks.
.
Another way to synthesize potassium benzoate in the lab setting is by reacting methyl benzoate with potassium thioacetate.
of food preservation begins with the absorption of benzoic acid into the cell. If the intracellular pH
changes to 5 or lower, the anaerobic fermentation
of glucose
through phosphofructokinase
is decreased by 95%.
(vitamin C), sodium
and potassium benzoate may form benzene
, a known carcinogen
. Heat, light and shelf life can affect the rate at which benzene is formed. The Food and Drug Administration
was performing tests in 2006, but the Environmental Working Group
is calling for the FDA to publicly release all tests and use their authority to force companies to reformulate to avoid the potential benzene forming combination.
Potassium benzoate was recently described by the Food Commission, who campaign for 'safer, healthier food in the UK', as "mildly irritant to the skin, eyes and mucous membranes".
Cat
s have a significantly lower tolerance to benzoic acid and its salts than rat
s and mice
.
shows 5 unique peaks. There are four peaks between 130-140 ppm from the carbons in the benzene ring. There is an additional carbon peak around 178 ppm representing the carbon from the carbonyl.
since the 1992 airing of "Treehouse of Horror III
". In the scene, a shopkeeper is selling Homer Simpson a cursed doll, which comes with a free cursed frogurt that came with free toppings that contain potassium benzoate (the presence of the additive is referred to as "bad").
Benzoic acid
Benzoic acid , C7H6O2 , is a colorless crystalline solid and the simplest aromatic carboxylic acid. The name derived from gum benzoin, which was for a long time the only source for benzoic acid. Its salts are used as a food preservative and benzoic acid is an important precursor for the synthesis...
, is a food preservative
Preservative
A preservative is a naturally occurring or synthetically produced substance that is added to products such as foods, pharmaceuticals, paints, biological samples, wood, etc. to prevent decomposition by microbial growth or by undesirable chemical changes....
that inhibits the growth of mold
Mold
Molds are fungi that grow in the form of multicellular filaments called hyphae. Molds are not considered to be microbes but microscopic fungi that grow as single cells called yeasts...
, yeast
Yeast
Yeasts are eukaryotic micro-organisms classified in the kingdom Fungi, with 1,500 species currently described estimated to be only 1% of all fungal species. Most reproduce asexually by mitosis, and many do so by an asymmetric division process called budding...
and some bacteria. It works best in low-pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
products, below 4.5, where it exists as benzoic acid.
Acidic foods and beverages such as fruit juice (citric acid
Citric acid
Citric acid is a weak organic acid. It is a natural preservative/conservative and is also used to add an acidic, or sour, taste to foods and soft drinks...
), sparkling drinks (carbonic acid
Carbonic acid
Carbonic acid is the inorganic compound with the formula H2CO3 . It is also a name sometimes given to solutions of carbon dioxide in water, because such solutions contain small amounts of H2CO3. Carbonic acid forms two kinds of salts, the carbonates and the bicarbonates...
), soft drink
Soft drink
A soft drink is a non-alcoholic beverage that typically contains water , a sweetener, and a flavoring agent...
s (phosphoric acid
Phosphoric acid
Phosphoric acid, also known as orthophosphoric acid or phosphoric acid, is a mineral acid having the chemical formula H3PO4. Orthophosphoric acid molecules can combine with themselves to form a variety of compounds which are also referred to as phosphoric acids, but in a more general way...
), and pickles
Pickling
Pickling, also known as brining or corning is the process of preserving food by anaerobic fermentation in brine to produce lactic acid, or marinating and storing it in an acid solution, usually vinegar . The resulting food is called a pickle. This procedure gives the food a salty or sour taste...
(vinegar
Vinegar
Vinegar is a liquid substance consisting mainly of acetic acid and water, the acetic acid being produced through the fermentation of ethanol by acetic acid bacteria. Commercial vinegar is produced either by fast or slow fermentation processes. Slow methods generally are used with traditional...
) may be preserved with potassium benzoate. It is approved for use in most countries including Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, the U.S.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, and the EU, where it is designated by the E number
E number
E numbers are number codes for food additives that have been assessed for use within the European Union . They are commonly found on food labels throughout the European Union. Safety assessment and approval are the responsibility of the European Food Safety Authority...
E212. In the EU, it is not recommended for consumption by children.
Potassium benzoate is also used as the whistle in many fireworks.
Synthesis
One very common way to make potassium benzoate is by oxidizing tolueneToluene
Toluene, formerly known as toluol, is a clear, water-insoluble liquid with the typical smell of paint thinners. It is a mono-substituted benzene derivative, i.e., one in which a single hydrogen atom from the benzene molecule has been replaced by a univalent group, in this case CH3.It is an aromatic...
.
Another way to synthesize potassium benzoate in the lab setting is by reacting methyl benzoate with potassium thioacetate.
Mechanism of food preservation
The mechanismMechanism of action
In pharmacology, the term mechanism of action refers to the specific biochemical interaction through which a drug substance produces its pharmacological effect...
of food preservation begins with the absorption of benzoic acid into the cell. If the intracellular pH
Intracellular pH
All cells contain an intracellular fluid whose pH value is known as the intracellular pH . The pHi plays a critical role in the function of the cell, and close regulation is required for cells to survive...
changes to 5 or lower, the anaerobic fermentation
Fermentation (food)
Fermentation in food processing typically is the conversion of carbohydrates to alcohols and carbon dioxide or organic acids using yeasts, bacteria, or a combination thereof, under anaerobic conditions. Fermentation in simple terms is the chemical conversion of sugars into ethanol...
of glucose
Glucose
Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...
through phosphofructokinase
Phosphofructokinase
Phosphofructokinase-1 is the most important regulatory enzyme of glycolysis. It is an allosteric enzyme made of 4 subunits and controlled by many activators and inhibitors...
is decreased by 95%.
Safety and health
In combination with ascorbic acidAscorbic acid
Ascorbic acid is a naturally occurring organic compound with antioxidant properties. It is a white solid, but impure samples can appear yellowish. It dissolves well in water to give mildly acidic solutions. Ascorbic acid is one form of vitamin C. The name is derived from a- and scorbutus , the...
(vitamin C), sodium
Sodium benzoate
Sodium benzoate has the chemical formula NaC6H5CO2; it is a widely used food preservative, with E number 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.-Uses:Sodium benzoate is a...
and potassium benzoate may form benzene
Benzene
Benzene is an organic chemical compound. It is composed of 6 carbon atoms in a ring, with 1 hydrogen atom attached to each carbon atom, with the molecular formula C6H6....
, a known carcinogen
Carcinogen
A carcinogen is any substance, radionuclide, or radiation that is an agent directly involved in causing cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes...
. Heat, light and shelf life can affect the rate at which benzene is formed. The Food and Drug Administration
Food and Drug Administration
The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...
was performing tests in 2006, but the Environmental Working Group
Environmental Working Group
The Environmental Working Group is an American environmental organization that specializes in research and advocacy in the areas of toxic chemicals, agricultural subsidies, public lands, and corporate accountability...
is calling for the FDA to publicly release all tests and use their authority to force companies to reformulate to avoid the potential benzene forming combination.
Potassium benzoate was recently described by the Food Commission, who campaign for 'safer, healthier food in the UK', as "mildly irritant to the skin, eyes and mucous membranes".
Cat
Cat
The cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...
s have a significantly lower tolerance to benzoic acid and its salts than rat
Rat
Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus...
s and mice
Mouse
A mouse is a small mammal belonging to the order of rodents. The best known mouse species is the common house mouse . It is also a popular pet. In some places, certain kinds of field mice are also common. This rodent is eaten by large birds such as hawks and eagles...
.
Carbon 13 NMR
The carbon NMRNMR
NMR may refer to:Applications of Nuclear Magnetic Resonance:* Nuclear magnetic resonance* NMR spectroscopy* Solid-state nuclear magnetic resonance* Protein nuclear magnetic resonance spectroscopy* Proton NMR* Carbon-13 NMR...
shows 5 unique peaks. There are four peaks between 130-140 ppm from the carbons in the benzene ring. There is an additional carbon peak around 178 ppm representing the carbon from the carbonyl.
Infrared spectrum
The following are the main peaks in the IR spectrum.- 1610: C=O from carbonylCarbonylIn organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom: C=O. It is common to several classes of organic compounds, as part of many larger functional groups....
- 1580: C=C from benzeneBenzeneBenzene is an organic chemical compound. It is composed of 6 carbon atoms in a ring, with 1 hydrogen atom attached to each carbon atom, with the molecular formula C6H6....
ring
Popular culture
Potassium benzoate as a food ingredient has been mocked by fans of The SimpsonsThe Simpsons
The Simpsons is an American animated sitcom created by Matt Groening for the Fox Broadcasting Company. The series is a satirical parody of a middle class American lifestyle epitomized by its family of the same name, which consists of Homer, Marge, Bart, Lisa and Maggie...
since the 1992 airing of "Treehouse of Horror III
Treehouse of Horror III
"Treehouse of Horror III" is the fifth episode of The Simpsons fourth season. It originally aired on the Fox network in the United States on October 29, 1992. In the third annual Treehouse of Horror episode, Homer buys Bart an evil talking Krusty doll, King Homer is captured by Mr. Burns, and Bart...
". In the scene, a shopkeeper is selling Homer Simpson a cursed doll, which comes with a free cursed frogurt that came with free toppings that contain potassium benzoate (the presence of the additive is referred to as "bad").