3-Methylnonane-2,4-dione – An Intense Odour Compound Formed during Flavour Reversion of Soya-Bean Oil

✍ Scribed by Guth, H. ;Grosch, W.

• Book ID: 102932429
• Publisher: John Wiley and Sons
• Year: 1989
• Weight: 542 KB
• Volume: 91
• Category: Article
• ISSN: 0931-5985
• DOI: 10.1002/lipi.19890910604

✦ Synopsis

Nonane-2,4-dione and 3-methylnonane-2,4-dione were identified in reverted soya-bean oil. The odour threshold of the latter compound, which smelled "lard-like, strawy, fruity", was very \ow (0.01 ng/l air) in comparison to that of the nonane-2,4-dione (3.9 ng/l air). Based on its odour properties and the result of an aroma extract dilution analysis, which have been recently reported (Fat Sci. Technol. 90,332 [1988]), it was concluded that 3-methylnonane-2,4-dione contributed very strongly to the reversion odour of soya-bean oil. 3-Methylnonane-2,4-dione, 3,7-dimethyloctane-2,4-dione, decane-2,5-, -3,5-and -4,5-dione, 3-0x0-and 5-oxodecanal were prepared as reference for the identification experiments. The spectroscopic ('H-NMR, MS) and odour threshold data are reported.