This is only an excerpt of the full article that appeared in P&F Magazine. The full content is not currently available online.
The main heterocyclic aroma chemicals are oxygen-, sulfur- and nitrogencontaining rings. The oxygen-containing heterocyclic aroma chemicals belong to the oxirane, furan, pyran and oxepine groups. The sulfur-containing aroma chemicals belong to the thiophene family and, together with nitrogen, to the thiazole and dithiazine systems. Nitrogen-containing aroma chemicals belong to pyrrole, indole, pyridine, quinoline, pyrazine and quinoxaline systems and, together with sulfur, as mentioned above, the thiazole and dithiazine families. This article will describe the oxygen-containing heterocyclic aroma chemicals.
Due to the highly potent odor character of a majority of the heterocyclic compounds used in fl avors and fragrances, the term ϕ Value will be used for some of the materials described. A relatively new concept, ϕ Value gives a better understanding of the odor intensity of a single molecule, taking into consideration its molecular mass (MM), analogous to ε value in UV/VIS data of particular molecules.
ϕ Value of a molecule is defi ned as the following:1