Сорбат калия

Описание

Potassium sorbate is a white crystalline powder. It is a potassium salt of sorbic acid.It was originally discovered in the 1850’s, and was derived from the Mountain Ash Tree. Today, potassium sorbate is synthetically created.Potassium sorbate is a good food preservatives, fully degradable, similar to fatty acids found naturally in foods. It is used to slow the growth of molds and yeasts in foods. It is commonly found in margarine, wines, cheeses, yogurts, soft drinks, and baked goods. Potassium sorbate has been used has a food preservative for many years. There have been extensive long-term tests that have confirmed its safety and it is on the Center for Science in the Public Interest list of safe additives.

Химические свойства

Potassium sorbate occurs as a white crystalline powder with a faint, characteristic odor.

Физические свойства

Colorless or white crystalline solid; density 1.36 g/cm³; decomposes at 270°C; soluble in water, 58 g/100 g solution; moderately soluble in alcohol.

Использование

Sorbic acid and its potassium salt is commonly employed as food preservative in wide range of foodstuffs, such as cheese, pickles, sauces and wines.
Potassium sorbate is a food grade preservative generally regarded as safe (GRAS) worldwide. It is the inactive salt of sorbic acid. It readily dissolves in water where it converts to sorbic acid, its active form, at a low pH. Sorbic acid is very pH dependent. While it shows some activity up to pH 6 (about 6%), it is most active at pH 4.4 (70%). At pH 5.0 it is 37% active. As sorbic acid, it is considered to be active against mold, fair against yeast and poor against most bacteria. Sorbic acid is an unsaturated fatty acid and as such is subject to oxidation (use of an antioxidant like Mixed Tocopherols T50 is recommended). It is also sensitive to UV light and may turn yellow in solution. Gluconolactone is reported to stabilize potassium sorbate against discoloration and darkening in aqueous solutions and may be useful in stabilizing sorbic acid in the water phase of a product.

Определение

ChEBI: A potassium salt having sorbate as the counterion.

Методы производства

Potassium sorbate is prepared from sorbic acid and potassium hydroxide.

Подготовка

Potassium sorbate is prepared by reacting potassium hydroxide with sorbic acid, followed by evaporation and crystallization:CH₃CH=CHCH=CHCOOH + KOH →CH₃CH=CHCH=CHCOOK + H₂O.

Общее описание

Sorbates have been reported to be less toxic than benzoate and have been classified as “Generally Recognized as Safe” (GRAS) additives by the U.S. Food and Drug Administration (FDA).Sorbic acid is metabolised to mainly to carbon dioxide. While the minor amounts are converted to trans,trans-muconic acid (ttMA), which is excreted unchanged into the urine. Urinary ttMA is a biomarker for the occupational and environmental exposure to benzene. Ability of trans,trans-2,4-Hexadienoic acid potassium salt (Sorbic acid potassium salt, Potassium sorbate) to induce chromosome aberrations, sister chromatid exchanges (SCE) and gene mutations in cultured Chinese hamster V79 cells has been examined.Potassium sorbate is reported to be less genotoxic than the sodium salt analog.

Фармацевтические приложения

Potassium sorbate is an antimicrobial preservative, with antibacterial and antifungal properties used in pharmaceuticals, foods, enteral preparations, and cosmetics. Generally, it is used at concentrations of 0.1–0.2% in oral and topical formulations, especially those containing nonionic surfactants. Potassium sorbate has been used to enhance the ocular bioavailability of timolol.
Potassium sorbate is used in approximately twice as many pharmaceutical formulations as is sorbic acid owing to its greater solubility and stability in water. Like sorbic acid, potassium sorbate has minimal antibacterial properties in formulations above pH 6.

Токсикология

Potassium sorbate is a skin, eye and respiratory irritant. Although some research implies it has a long term safety record, in vitro studies have shown that it is both genotoxic and mutagenic to human blood cells. Potassium sorbate is found to be toxic to human DNA in peripheral blood lymphocytes (type of white blood cells), and hence found that it negatively affects immunity. It is often used with ascorbic acid and iron salts as they increase its effectiveness but this tends to form mutagenic compounds that damage DNA molecules.
Potassium sorbate exhibits low toxicity with LD₅₀ (rat, oral) of 4.92 g / kg, similar to that of table salt . Typical usage rates of potassium sorbate are 0.025 % to 0.1 % (see sorbic acid), which in a 100 g serving yields intake of 25 mg to 100 mg. Acceptable daily intakes for human is 12.5 mg / kg, or 875 mg daily for an average adult (70 kg), according to FAO/World Health Organization Expert Committee on Food Additives.

Безопасность

Potassium sorbate is used as an antimicrobial preservative in oral and topical pharmaceutical formulations and is generally regarded as a relatively nontoxic material. However, some adverse reactions to potassium sorbate have been reported, including irritant skin reactions which may be of the allergic, hypersensitive type. There have been no reports of adverse systemic reactions following oral consumption of potassium sorbate.
The WHO has set an estimated total acceptable daily intake for sorbic acid, calcium sorbate, potassium sorbate, and sodium sorbate expressed as sorbic acid at up to 25 mg/kg body-weight.
(mouse, IP): 1.3 g/kg
(rat, oral): 4.92 g/kg
See also Sorbic Acid.

хранилище

Potassium sorbate is more stable in aqueous solution than sorbic acid; aqueous solutions may be sterilized by autoclaving.
The bulk material should be stored in a well-closed container, protected from light, at a temperature not exceeding 40°C.

Несовместимости

Some loss of antimicrobial activity occurs in the presence of nonionic surfactants and some plastics.

Регуляторный статус

GRAS listed. Accepted for use as a food additive in Europe. Included in the FDA Inactive Ingredients Database (nasal sprays; oral capsules, solutions, suspensions, syrups, tablets; topical creams and lotions). Included in nonparenteral medicines licensed in the UK. Included in the Canadian List of Acceptable Non-medicinal Ingredients.