Trimethyl-pyrazine

Chemical Properties

CLEAR YELLOW LIQUID

Chemical Properties

2,3,5-Trimethylpyrazine has a baked potato or roasted nut aroma.

Occurrence

Reported present in bakery products, roasted barley, cocoa products, coffee, dairy products, meat, peanuts, filberts, pecans, popcorn, potato products, rum and whiskey, soy products, raw asparagus, baked potato, wheaten bread, crispbread, Swiss cheese, coffee, black tea, green tea, roasted barley, roasted filbert, heated beef, roasted peanut, soybean, raw beans, coriander seed, scallop, guava, kohlrabi, bell pepper, blue, Swiss and Gruyere cheese, boiled egg, fatty fish, beer, sherry, barley, peanut, oat products, coconut, beans, mushroom, trassi, almond, macadamia nut, sesame seed, coriander seed, rice, licorice, sweet corn, malt, peated malt, wort, krill, fermented shrimp, crab, okra, crayfish, clam, scallop and squid.

Uses

Trimethylpyrazine is a key aroma compound of dark chocolates differing in organoleptic properties.

Uses

2,3,5-Trimethylpyrazine can be used as a flavor ingredient in food industries.

Definition

ChEBI: Trimethylpyrazine is a member of the class of pyrazines that is pyrazine in which three hydrogens at positions 2, 3 and 5 have been replaced by methyl groups. It has a role as a plant metabolite, a flavouring agent, a bacterial metabolite, an animal metabolite and a pheromone.

Preparation

From 2,5-dimethylpyrazine by ring alkylation with MeLi; by condensing propylenediamine with 2,3-butanedione.

Aroma threshold values

Detection: 400 ppb to 9 ppm (9 ppm in water)

Taste threshold values

Taste characteristics at 80 ppm: raw, musty, nutty and potato.

General Description

2,3,5-Trimethylpyrazine is present in brown cheese.

Safety Profile

Moderately toxic by ingestion. Combustible liquid. When heated to decomposition emits toxic fumes of NOx.