References: The secret is sulphur

CAS

Flavour description

threshold

concentration

75-18-3

extremely diffusive, repulsive, reminiscent of wild radish, sharp, green, cabbage like; in high dilution bearable, almost acceptable, pleasant, vegetable like

vary between 0.3 and 60.0 ppb; 1 ppb and 0. 33 ppb

0.5-3.5 in roasted coffee and 0.1-3.5 ppm in green coffee (Rhoades 1960); 0.1-0.2 ppm in healthy roasted arabica but 0.8-1.0 ppm in one having a stinking quality by Guyot and Vincent (1990)

624-92-0

intensive onion-like character

3 ppb to 7.6 ppb in water and 12 ppb

0.01 ppm in arabicas and 0.10-0.12 ppm in Robustas by Silwar et al. (1986) 0.04-0.05 ppm in a roasted healthy arabica and 0.3 – 0.4 in the stinking quality by Guyot and Vincent (1990)

3658-80-8

powerful, diffusive, penetrating odour of fresh onion, cabbage, burnt, cooked

0.01 ppb

1 ppb in two arabicas and 0.1 ppm in two other arabicas by Silwar et al 1986

74-93-1

Rotten cabbage; one of the most intense noted to roasted coffee

0,02 – 2.1 ppb in water

1.5-4.3 in roasted coffee and 0.1-0.3 ppm in green coffee by Rhoades 1960

5287-45-6

pure substance smells pungent or leek like; at 0.1 ppm penetrating animal like, foxy, skunky; at 0.4 ppm skunky, meaty, coffee, fatty, tarry

0.2-0.4 g/m^3 in air and 0.2 – 0.3 ppt (0.0002-0.0003 µg/L) in water

8.2 ppb in freshly roasted ground coffee by Grosch (1996)

98-02-2

classic coffee odor, extremely powerful, diffusive penetration odor, in proper dilution gives coffee-like, caramel-like-burnt, sweet

0.04ppb down to 5 ppt

1.1 ppm in arabica and 2.0 ppm in Robusta by Tressl and Silwar 1981, similar from Silwar 1986 and Tressl 1989; 1.7 ppm in a Columbian arabica by Grosch et al 1993 and 1.95 ppm in an Indonesian Robusta; 1.08 ppm for an arabica and 1.73 ppm for a Robusta by Semmelroch et al 1995

28588-74-1

meat like, roasted coffee

0.005-0.01 ppb

0.148 ppm in a Columbia arabica and 0.195 in a Kenya arabica by Grosch et al 1996

3268-49-3

powerful, diffusive onion and meat like, in dilution more pleasant, less onion-like, reminiscent of bouillon; at 2 ppm typical meaty and sulfur flavor

0.2 ppb in water; and 9 µg/kg in cellulose

240 ppb in Columbian arabica and 95 ppb in an Indonesia Robusta  Semmelroch et al. 1995 ; 22 ppb in green arabica and 213 ppb after roasting Czerny and Grosch 2000

50746-10-6

sweaty, fruity odor, becoming black currant and catty in aqueous solution at 0. 1 ppm; penetrating sweaty and catty; belong to the most potent odors; at 0.1 ppm tropical, fruit, green, sulfur, hop flavor and black currant, leaves, clary sage and orange flowers; in great dilution in a coffee beverage roast coffee likeness

2-5 ppt odor thresholds and 5-8 ppt taste threshold; 3 * 10-4 µg/m3 in air and 3.5 ppt in water

0.13 ppm in arabica and 0.115 ppm in Robusta by Semmelroch et al 1995