Overview of Flavor and Fragrance Materials

The Significance of Volatile Sulfur Compounds in Food Flavors

“…Other potent odorants in roasted coffee include 5-methylfurfurylthiol (0.05 ppb threshold), which smells meaty at 0.5-1 ppb, and changes character to a sulfury mercaptan note at higher levels (89). Furfuryl methyl disulfide has a sweet mocha coffee aroma (63). While other sulfur compounds such as 3-mercapto-3-methylbutyl formate and 3-methyl-2-buten-1-thiol were previously thought to be important factors for coffee aroma, recent studies have confirmed that the flavor profile of brewed coffee is primarily contributed by 2-furfurylthiol, 4-vinylguaiacol, and "malty"-smelling Strecker aldehydes, among others (88,90).…”

“…2-Methyl-3-furanthiol also occurs in canned tuna fish aroma (95). The disulfide has a recognizable aroma character of "rich aged-beef, prime-rib" (63). Both compounds are produced from the thermal degradation of thiamin (96).…”

“…It is suspected that a trace impurity (2-methyltetrahydrofuran-3-thiol) in sulfurol is the actual "beef broth" character impact compound (63). Another reaction product flavor chemical, 2,5-dimethyl-1,4-dithiane-2,5-diol (the dimer of mercaptopropanone), has an intense chicken-broth odor.…”

Flavors and Fragrances, 3. Aromatic and Heterocyclic Compounds

“…20 4 0.954-0.962, n 20 D 1.478-1.483, with powerful leafy-green, nasturtium, and hyacinth note. It can be synthesized by reaction of a 1:1 molar ratio of ethyl vinyl ether and phenethyl alcohol in the presence of cation-exchange resin [2]. It imparts fresh, floral, green notes and is used in fine fragrances as well as in soap, cosmetics and detergents.…”

Selective Palladium‐Catalyzed Hydroformylation of Alkynes to α,β‐Unsaturated Aldehydes

“…This is somewhat surprising as such transformations provide in principle a 100 % atom-efficient route for producing a,b-unsaturated aldehydes, which are important intermediates in organic synthesis, [6] particularly for the preparation of bioactive compounds, flavors, and fragrances. [7] In early studies, it was found that the hydroformylation of alkynes usually suffers from low chemoselectivity and/or low yield of the desired unsaturated aldehyde, primarily because the formation of the corresponding saturated aldehydes and alkenes is hardly suppressed. [8] However, during the past two decades, more effective catalysts such as [Rh(CO) 2 (acac)]/ Biphephos (acac = acetylacetonate, Biphephos = 6,6'-[(3,3'di-tert-butyl-5,5'-dimethoxy-1,1'-biphenyl-2,2'-diyl)bis(oxy)]bis(dibenzo[d,f][1,3,2]dioxaphosphepin)]), [9] the heterobimetallic catalyst [PdCl 2 (PCy 3 ) 2 ]/[Co 2 (CO) 8 ], [10] and a zwitterionic rhodium complex with PPh 3 as a ligand [11] were developed.…”