Predictability is not really in the cards for the thiazole family. This makes them a very interesting chemical category. Odors range quite dramatically from roasted and nutty, through peach skins, to tomato leaves. 2-Ethyl-4-methylthiazole (FEMA# 3680, CAS# 15679-12-6) has some roasted aspects, but it is quite specifically nutty and cocoa in character. There is also an interesting second link to 2-isopropyl-4-methylthiazole, a closely related thiazole, which gives especially interesting results in fruit flavors. These connections mean that 2-ethyl-4-methylthiazole can be used in a very wide range of different flavors, often in combination with other related notes.
Predictability is not really in the cards for the thiazole family. This makes them a very interesting chemical category. Odors range quite dramatically from roasted and nutty, through peach skins, to tomato leaves. 2-Ethyl-4-methylthiazole (FEMA# 3680, CAS# 15679-12-6) has some roasted aspects, but it is quite specifically nutty and cocoa in character. There is also an interesting second link to 2-isopropyl-4-methylthiazole, a closely related thiazole, which gives especially interesting results in fruit flavors. These connections mean that 2-ethyl-4-methylthiazole can be used in a very wide range of different flavors, often in combination with other related notes.
Note that the dose rates given throughout this article are the levels suggested for use in flavors intended to be dosed at 0.05% in ready-to-drink beverages or in a simple bouillon.
Brown Flavors
Bread: The level of any cooked note in bread flavor is heavily influenced by the type of bread. A good starting point is 20 ppm of 2-ethyl-4-methylthiazole.
Chocolate and cocoa: The trivial name of this ingredient is chocolate thiazole. This gives a hint that it has a quite specifically cocoa aroma. Levels of 100 ppm of 2-ethyl-4-methylthiazole gives a huge boost to cocoa flavors, and levels around 50 ppm are better in chocolate flavors.
Coffee: The specifically cocoa notes do not hold this ingredient back in coffee flavors. Levels vary, but even 200 ppm works well in high roast style flavors.
Malt: Malt flavors are a different story. Just a touch, around 10 ppm, lifts malt flavors nicely. Similar or lower levels are effective in malted milk flavors.
Tea: 2-Ethyl-4-methylthiazole makes a great contribution to all types of tea flavors. As might be expected, the highest level, around 50 ppm, works well in black tea flavors. Levels of 20 ppm are good for green tea flavors and 30 ppm is ideal for red tea flavors, such as oolong.
For the full article, please check out the Perfumer & Flavorist+ August 2022 issue.
