What Is Acetoin?
Acetoin is a chemical compound with the molecular formula C4H8O2.
Acetoin, also known as 3-hydroxy-2-butanone or acetylmethylcarbinol, is classified as an α-hydroxy ketone (acyloin) due to its adjacent carbonyl and hydroxy groups in the molecule.
Uses of Acetoin
Acetoin serves primarily as a flavoring agent, widely used in various food products for its distinctive aroma reminiscent of butter or yogurt. It is commonly added to confectionery, margarine, coffee, caramel, tobacco, and dairy products.
Naturally, acetoin is produced during the aging of cream for butter production, and it is also found as an aroma component in fermented foods, vegetables, and fruits.
Properties of Acetoin
At room temperature, acetoin is a colorless to light yellow liquid with a buttery odor. It has a molecular weight of 88.11, a melting point of 15°C, and a boiling point of 148°C. Acetoin is readily soluble in water, ethanol, propylene glycol, ether, and dichloromethane, but slightly soluble in hydrocarbon solvents.
Types of Acetoin
1. Reagent Products for Research and Development
Acetoin is available in various capacities for research purposes, typically sold in frozen or refrigerated form.
2. Flavoring Agent
Industrial and commercial flavoring agents containing acetoin are available, with detailed product information provided by individual manufacturers.
Other Information on Acetoin
1. Synthesis of Acetoin
Acetoin can be synthesized through various methods, including thiazolium salt-catalyzed benzoin condensation of acetaldehyde, acyloin condensation of acetic acid esters, microbial oxidation of 2,3-butanediol, and fermentation of sorbose.
2. Chemical Reaction of Acetoin
At room temperature, acetoin undergoes a chemical reaction resulting in the formation of a hemiacetalated dimer. This dimer can be converted back to a monomer by heating above its melting point.
3. Hazard and Regulatory Information of Acetoin
Acetoin is classified as a flammable liquid: Category 3 and should be handled with care, keeping it away from ignition sources. It is designated as a hazardous and flammable substance under industrial safety and health laws and regulations.