biacetyl

Biacetyl, also known as 2,3-butanedione, is a naturally occurring organic compound. It is a diketone with the chemical formula C4H6O2. Biacetyl is characterized by its strong, buttery odor and flavor, which is a significant component of the aroma of butter and dairy products. It is also found in some fruits, coffee, and chocolate, and it is produced during the fermentation processes of certain beverages, such as beer and wine, by lactic acid bacteria.

In the food industry, biacetyl is widely used as a flavoring agent, particularly to impart a buttery taste to margarines, shortenings, popcorn, and confectionery. Its intense aroma means it is used in very small concentrations. While it is a natural component of many foods, its use as a food additive is subject to regulatory approval and limits in various countries.

Beyond its role in food, biacetyl has also been studied for its chemical properties and occurrence in other contexts. It can be synthesized chemically, and it is a byproduct of certain industrial processes. Exposure to high concentrations of biacetyl vapor has been linked to respiratory problems, specifically a condition known as "popcorn lung" or bronchiolitis obliterans, which has led to concerns and regulations regarding occupational exposure in factories that produce artificial butter flavoring.