An Overview of the Contribution of Sulfur-Containing Compounds to the Aroma in Heated Foods

Many of the most potent odorants found in foods contain sulfur. The exceptionally low odor threshold values of many of these compounds mean that only trace quantities are necessary to make a significant contribution to flavor. Heterocyclic sulfur compounds, including thiophenes, thiophenones, dithiolanes, trithiolanes, trithianes, thiazoles, and thienothiophenes, are typical products of thermal reactions in food. Non-heterocyclic sulfur compounds, such as thiols, sulfides and disulfides are also important to the aroma of heated foods. The main source of sulfur in the reactions that lead to these compounds is the amino acid, cysteine. Cysteine degradation, in the Maillard reaction or through hydrolysis, produces hydrogen sulfide, which is a vital reactant for the production of sulfur-containing aroma compounds. Other important sulfur-containing precursors are methionine and thiamin.