propionihappo

Propionihappo, known in English as propanoic acid, is a colorless, oily carboxylic acid with the formula C3H6O2 (CH3-CH2-COOH). It is a simple short-chain fatty acid and is commonly used in industry and food preservation. Its systematic IUPAC name is propanoic acid, and its CAS number is 503-74-2.

Propionihappo characteristics include a sharp, penetrating odor and properties typical of carboxylic acids. It boils at about 141 °C and melts near −16 °C. The compound is soluble in many organic solvents and is partially soluble in water. In solution, it behaves as a weak acid with a pKa around 4.87, meaning it partially dissociates in aqueous environments.

Production and occurrence can be described in two main ways. Industrially, propionihappo is produced by oxidation of propionaldehyde, which can be obtained by hydroformylation of ethylene. Propionate salts, such as sodium propionate and calcium propionate, are widely used as food preservatives and feed additives. Propionihappo also occurs naturally as a metabolic byproduct and is produced by certain bacteria during fermentation, notably Propionibacterium species, which contribute to the flavor of Swiss-type cheeses.

Uses of propionihappo include serving as a chemical building block in the synthesis of propionate esters, propionyl derivatives, and various flavors and fragrances. It is also employed as a preservative in bread, dairy products, and some processed foods, primarily in the form of its salt salts.

Safety considerations include its corrosive and irritant nature. Propionihappo can cause skin and eye irritation and should be handled with appropriate protective equipment in well-ventilated conditions. Proper storage in labeled, sealed containers is recommended to prevent degradation and exposure.