Diacetyl

• 2,3-butanedione
• Dimethylglyoxal
• Dimethyldiketon

Yellow-green liquid with a strong odor

Liquid

0.99 g · cm -3 ( 20 ° C)

-2.4 ° C

88 ° C (thermal decomposition above 110 ° C)

65 hPa ( 20 ° C)

• Good in water ( 250 g · l-1 at 20 ° C)
• Soluble in ethanol and diethyl ether

1.3951 (20 ° C)

Risk

Template: Infobox chemical / molecular formula search available

Diacetyl is an organic chemical compound selected from the group consisting of ketones and the simplest member of the class of diketones. It has a distinct taste and smell of butter and is also part of the natural butter flavor. Diacetyl is a positive Iodoformprobe.

The beer brewing process beer yeasts produce from the metabolic intermediate acetolactate, diacetyl, they further reduced to 2,3- butanediol. Failing the latter degradation or is forced by unfavorable nutrient contents the Diacetylfreisetzung, so get the beer a distinct and unpleasant off-taste. Similar processes with great influence on the taste of the wine found in the wine storage by specific lactic acid bacteria ( see also lactic acid fermentation or malolactic fermentation ) instead of ( → Wine error).

Harmful effect

Once back in May 2000, the health authorities of the State of Missouri about the disease of ten workers at a popcorn factory on bronchiolitis obliterans, an otherwise rather rare respiratory disease, reported and related to this called for the investigation of the factory by the U.S. Occupational Safety Health Administration OSHA - but without effective consequences - it came in July 2004 before a U.S. court in Iowa brings a lawsuit against the Symrise Inc., and a number of other butter flavoring manufacturers, which concerned claims for damages due to the illness of bronchiolitis obliterans, by inhaling of diacetyl vapors as they are released in the production of artificial flavoring microwave popcorn. Action had been brought employees of a food producer and middlemen, constituted the Symrise products in food processing. Additional actions related to the disease now known as "Popcorn Workers Lung " were before the courts in Illinois and St. Louis, Missouri, filed in the summer of 2005, until finally in June 2007, a draft legislation was introduced in the U.S. Congress, binding limits on the Diacetylbelastung define the workplace. As Der Spiegel reported little later, the manufacturer artificial butter flavor had already more than $ 100 million paid up to that point compensation to sick employees, and officially even the death of a human being was attributed to the disease. Beginning of September 2007 was finally the case of another, diagnosed in July, but until then ignored by the authorities to disease bronchiolitis obliterans known, this time with a man who had taken regularly and in large quantity home-cooked microwave popcorn and then ill with "Popcorn Workers Lung ", presumably because he had inhaled the case vacated diacetyl vapors in the preparation. Three weeks later, then passed the U.S. House of Representatives the Popcorn Workers Lung Disease Prevention Act, with which it undertook to OSHA to set mandatory standards for dealing with diacetyl. Recent research shows that diacetyl promotes various aspects of amyloid -beta aggregation. Such beta Agreggationen be associated with Alzheimer's disease.