Frank Ott

High-impact sulfur compounds: constitutional and configurational assignment of sulfur-containing heterocycles.

To unambiguously identify their structures and to evaluate their organoleptic properties, several constitutional und configurational isomers of dialkyl‐tetrathianes and dialkyl‐pentathiepanes were synthesized by two different synthetic protocols, and separated by preparative gas chromatography. Raman and NMR spectroscopy were used to differentiate between the constitutional 3,6‐dialkyl‐1,2,4,5‐tetrathiane and the 4,6‐dialkyl‐1,2,3,5‐tetrathiane isomers. Furthermore, cis‐ and trans‐isomers of 3,6‐dialkyl‐1,2,4,5‐tetrathianes were distinguished by temperature‐dependent NMR experiments. Static, quantum‐chemical simulations of the NMR spectra for these cis‐ and trans‐isomers were calculated in the gas layer in order to confirm our experimental assignments. In addition, the assignment of 4,7‐alkyl‐1,2,3,5,6‐pentathiepanes were deducted from their Raman spectra. Dialkyl‐tetrathianes and dialkyl‐pentathiepanes are interesting components to be used in flavor applications due to their unique olfactory impact and facets.

The flavour chemistry of culinary Allium preparations

Abstract In culinary preparations cooked, roasted and fried Allium products play a major role in the taste and the aroma of the final product. In this study the correlation of various culinary preparation techniques such as cooking and frying and the resulting differences in the flavour chemistry (volatiles and non-volatiles) are demonstrated. Different preparation techniques performed on shallots, garlic and/or scallions influence the profile of volatiles and non-volatiles in culinary preparations significantly.