Chemical Properties
2,5-Dimethylpyrazine has a characteristic odor of earthy, potato-like odor.
Chemical Properties
clear colorless to pale yellow liquid
Occurrence
Reported to be present in bakery products, roasted barley, cocoa products, roasted coffee, dairy products,
pork, peanuts, pecans, filberts, popcorn, potato products, rum and whiskey, soy products; a volatile component in roasted filberts and
in potato chips; reportedly identified in the fat of cooked beef; also reported found in toasted off-flavors. Also reported in cheeses,
butter, boiled eggs, grilled beef, tea, barley, oats, oatmeal, soybeans, heated beans, kohlrabi, shrimp and mushrooms. Also reported
found in coffee, potato chips and shrimp
Uses
2,5-Dimethyl pyrazine is used for blending food, nuts and beverage flavors.
Definition
ChEBI:2,5-Dimethylpyrazine is a member of pyrazines.
Preparation
By the interaction of acrolein and ammonia when heated in glycerol in the presence of ammonium salts; by self-condensation of aminoacetone, followed by oxidation with mercury chloride.
Aroma threshold values
Detection: 80 ppb to 1.8 ppm
Taste threshold values
Taste characteristics at 7.5 ppm: musty, potato, cocoa and nutty with a fatty and oily nuance
General Description
2,5-Dimethylpyrazine is a pyrazine compound that is mainly formed in food products such as cooked rice or roasted peanuts due to the Maillard reaction between sugars and proteins during cooking or roasting process.
Purification Methods
Purify it via its picrate (m 150o) which is decomposed with a base (e,g, KOH) and distilled. [Wiggins and Wise J Chem Soc 4780 1956]. [Beilstein 23/5 V 403.]
