trans-2-nonenal

Technical specification

Assessment

The best way to detect trans-2-nonenal in beer is as follows. Without covering the glass, swirl the beer to release the aroma. Take a single short sniff. Repeat as necessary.

Amount of flavour per capsule

730 ng per capsule

Threshold

The flavour threshold of trans-2-nonenal in beer is 50 – 250 ng / l.

Origins

Nonenal is formed during malt and wort production. After being formed, it binds to malt proteins. It is carried through the brewing process in this bound form before being released during storage of finished beer in bottles, cans or kegs.

Confusions

Nonenal is sometimes confused wth:

• 2,4,6-Trichloroanisole
• 2-Ethyl fenchol
• Isobutyraldehyde

Importance

Nonenal is an off-flavour in beer associated with ageing. Formation of this flavour is more pronounced when precautions have not been taken in relation to minimizing process oxidation.

CAS registry number

The CAS registry number for nonenal is 18829-56-6.

Other names

• (E)-heptylidene acetaldehyde
• (E)-3-hexyl acrolein
• (E)-3-hexyl-2-propenal
• (E)- non-2-enal
• trans-non-2-enal
• (E)-2-nonen-1-al
• trans-2-nonen-1-al
• (E)-2- nonenal
• trans-2- nonenal

Remarks

Sulphur dioxide in beer reversibly reacts with trans-2-nonenal to reduce its flavour impact.

Threshold distribution

Capsules per pot

10

Legal notices

This product is protected by the following trade marks and patents:

• US Patent no. D679900
• European Community Trade Mark
  Registration no. 009937574
• European Community Trade Mark
  Registration no. 009856527
• US Trade Mark Registration no. 4345057
• US Trade Mark Registration no. 4345056