Structure determination of 4-methyl-3-thiazoline in roasted sesame flavour

An aroma extract dilution analysis has recently revealed a garlic, carbide-like smelling compound with a comparatively high flavour dilution factor among the 41 odorants detected in the roasted sesame sample. By application of high-resolution mass spectrometry and NMR measurements followed by synthesis, this flavour compound has been identified as 4-methyl-3-thiazoline (1). The analytical data and details on the enrichment of 1 from roasted sesame are reported. The odorant exhibiting the very low odour threshold of 1 μg/L in water has been identified for the first time in a food flavour.