Alkylpyrazines are chemical compounds based on

pyrazine Pyrazine is a heterocyclic aromatic organic compound with the chemical formula C4H4N2. It is a symmetrical molecule with point group D2h. Pyrazine is less basic than pyridine, pyridazine and pyrimidine. It is a ''"deliquescent crystal or wax-lik ...

with different substitution patterns. Some alkylpyrazines are naturally occurring highly aromatic substances which often have a very low

odor threshold The odor detection threshold is the lowest concentration of a certain odor compound that is perceivable by the human sense of smell. The threshold of a chemical compound is determined in part by its shape, polarity, partial charges, and molecu ...

and contribute to the taste and aroma of various foods including cocoa, baked goods, coffee and wines. Alkylpyrazines are also formed during the cooking of some foods via

Maillard reaction The Maillard reaction ( ; ) is a chemical reaction between amino acids and reducing sugars that gives browned food its distinctive flavor. Seared steaks, fried dumplings, cookies and other kinds of biscuits, breads, toasted marshmallows, and man ...

Examples

File:2-Methylpyrazine.png , 2-Methylpyrazine (found in roasted sesame) File:2,3-Dimethyl Pyrazine Structural Formula V1.svg , 2,3-Dimethylpyrazine (found in roasted sesame) File:2,5-Dimethylpyrazin V1.svg , 2,5-Dimethylpyrazine (asparagus, tea, crispbread, malt, shrimp, soy, squid, Swiss chease, bread, roasted sesame) File:Tetramethylpyrazine.PNG , 2,3,5,6-Tetramethylpyrazine (nattō, fermented cocoa beans)

2-Methylpyrazine

2-Methylpyrazine was the volatile odorant found at the highest concentration in roasted

sesame Sesame ( or ; ''Sesamum indicum'') is a flowering plant in the genus ''Sesamum'', also called benne. Numerous wild relatives occur in Africa and a smaller number in India. It is widely naturalized in tropical regions around the world and is cu ...

seed oil.

2,3-Dimethylpyrazine

2,3-Dimethylpyrazine is a component of the aroma of roasted sesame seeds.

2,5-Dimethylpyrazine

2,5-Dimethylpyrazine is used as flavor additive and

odorant An aroma compound, also known as an odorant, aroma, fragrance or flavoring, is a chemical compound that has a smell or odor. For an individual chemical or class of chemical compounds to impart a smell or fragrance, it must be sufficiently vol ...

in foods such as

cereals A cereal is any grass cultivated for the edible components of its grain (botanically, a type of fruit called a caryopsis), composed of the endosperm, germ, and bran. Cereal grain crops are grown in greater quantities and provide more food en ...

and products such as

cigarettes A cigarette is a narrow cylinder containing a combustible material, typically tobacco, that is rolled into thin paper for smoking. The cigarette is ignited at one end, causing it to smolder; the resulting smoke is orally inhaled via the oppo ...

. It occurs naturally in

asparagus Asparagus, or garden asparagus, folk name sparrow grass, scientific name ''Asparagus officinalis'', is a perennial flowering plant species in the genus ''Asparagus''. Its young shoots are used as a spring vegetable. It was once classified in ...

, black or green

tea Tea is an aromatic beverage prepared by pouring hot or boiling water over cured or fresh leaves of '' Camellia sinensis'', an evergreen shrub native to East Asia which probably originated in the borderlands of southwestern China and northe ...

crispbread Crispbread ( sv, knäckebröd (lit. crack bread), ''hårt bröd'' (hard bread), ''hårdbröd'', ''spisbröd'' (stove bread), ''knäcke'', da, knækbrød, no, knekkebrød, fi, näkkileipä or näkkäri, et, näkileib, is, hrökkbrauð, fo, k ...

malt Malt is germinated cereal grain that has been dried in a process known as " malting". The grain is made to germinate by soaking in water and is then halted from germinating further by drying with hot air. Malted grain is used to make beer, wh ...

, raw

shrimp Shrimp are crustaceans (a form of shellfish) with elongated bodies and a primarily swimming mode of locomotion – most commonly Caridea and Dendrobranchiata of the decapod order, although some crustaceans outside of this order are refer ...

, soya,

squid True squid are molluscs with an elongated soft body, large eyes, eight arms, and two tentacles in the superorder Decapodiformes, though many other molluscs within the broader Neocoleoidea are also called squid despite not strictly fitting t ...

Swiss cheese Swiss cheese may refer to: Cheese * List of Swiss cheeses (from Switzerland) * Swiss-type cheeses or Alpine cheeses, a class of cooked pressed cheeses now made in many countries * Swiss cheese (North America), any of several related varieties o ...

s, and wheat bread. It's also found in roasted sesame. The chemical formula is C₆H₈N₂.

2,6-Dimethylpyrazine

2,6-Dimethylpyrazine is also used as flavor additive and odorant in foods such as cereals and products such as cigarettes. It occurs naturally in baked

potato The potato is a starchy food, a tuber of the plant ''Solanum tuberosum'' and is a root vegetable native to the Americas. The plant is a perennial in the nightshade family Solanaceae. Wild potato species can be found from the southern Unit ...

, black or green tea, crispbread,

French fries French fries (North American English), chips (British English), finger chips ( Indian English), french-fried potatoes, or simply fries, are '' batonnet'' or ''allumette''-cut deep-fried potatoes of disputed origin from Belgium and France. Th ...

peated malt Mash ingredients, mash bill, mashbill, or grain bill are the materials that brewers use to produce the wort that they then ferment into alcohol. Mashing is the act of creating and extracting fermentable and non-fermentable sugars and flavor co ...

, raw asparagus, roasted

barley Barley (''Hordeum vulgare''), a member of the grass family, is a major cereal grain grown in temperate climates globally. It was one of the first cultivated grains, particularly in Eurasia as early as 10,000 years ago. Globally 70% of barley pr ...

, roasted filberts or

pecans The pecan (''Carya illinoinensis'') is a species of hickory native to the southern United States and northern Mexico in the region of the Mississippi River. The tree is cultivated for its seed in the southern United States, primarily in Georgia, ...

, squid, wheat bread,

wild rice Wild rice, also called manoomin, Canada rice, Indian rice, or water oats, is any of four species of grasses that form the genus ''Zizania'', and the grain that can be harvested from them. The grain was historically gathered and eaten in both ...

(Zizania aquatica), and

wort Wort () is the liquid extracted from the mashing process during the brewing of beer or whisky. Wort contains the sugars, the most important being maltose and maltotriose, that will be fermented by the brewing yeast to produce alcohol. Wort ...

. It's also found in roasted sesame. The chemical formula is C₆H₈N₂.

2,3,5,6-Tetramethylpyrazine

Tetramethylpyrazine Tetramethylpyrazine, also known as ligustrazine, is a chemical compound found in nattō and in fermented cocoa beans. In an observational study, tetramethylpyrazine was the dominant volatile organic compound in one Sourdough#Starter, sourdough star ...

(ligustrazine) is found in

nattō , spelled as natto in standard English language use, is a traditional Japanese food made from whole soybeans that have been fermented with ''Bacillus subtilis'' var. ''natto''. It is often served as a breakfast food with rice. It is served wit ...

and in fermented

cocoa bean The cocoa bean (technically cocoa seed) or simply cocoa (), also called the cacao bean (technically cacao seed) or cacao (), is the dried and fully fermented seed of ''Theobroma cacao'', from which cocoa solids (a mixture of nonfat substances ...

s.Effect of mass and turning time on free amino acid, peptide-N, sugar and pyrazine concentration during cocoa fermentation. P Hashim, J Selamat, S Muhammad, S Kharidah and A Ali, Journal of the Science of Food and Agriculture, 1998, Volume 78, pages 543–550.

References

{{reflist Pyrazines