Combinatorial synthesis and sensorial properties of polyfunctional thiols

Over the past few years, polyfunctional thiols present as trace components have been found to play a major role in many food flavors, due to their exc eptionally low odor thresholds. Unfortunately, their presence in minute con centration (in ng/kg to a few mug/kg) and their high reactivity make it ver y difficult to extract and identify them. Furthermore, most of them are not yet commercially available. The aim of this work was to characterize the c hromatographic and sensorial properties of 10 synthetic mercaptoketones and mercaptoalcohols. Combinatorial chemistry proved to be a very useful way t o synthesize them rapidly. Sulfur-selective sulfur chemiluminescence detect ion chromatograms coupled with mass spectroscopy enabled the target compoun ds to be identified. Flavor profiles and best estimate gas chromatography l owest amount detected by sniffing (BE-GC-LOADS) values were further determi ned by GC-olfactometry. As expected, new, exceptionally odorant molecules ( BE-GC-LOADS < 0.1 ng) were revealed by this unusual approach.