During the cooking process of meat, large quantities of volatile compounds are formed, such as aldehydes, ketones, hydrocarbons, furans, thiazoles, and pyrazines
; these compounds directly affect flavor [9,10].
The main compounds eliciting green/ vegetal flavors in wine are alkl-methoxypyrazines (also known as MPs, and often simply referred to as pyrazines
), C6 green leaf volatiles (particularly hexanols and hexanals) and some thiols.
Compounds such as alcohols, aldehydes, ketones, organic acids, esters, pyrazines
, and phenols, among others, are produced during fermentation, contributing to the final flavor profile of chocolate .
In addition, some pyrazines
appeared to be important to the nutty aroma of Parmigiano Reggiano.
According to a study by , roasted chicory roots contain various compounds like 2-acetylpyrrole, furfural, phenyl acetaldehyde, phenyl acetic acid, vanillin, pyrazines
, benzothiazoles, aldehydes, aromatic hydrocarbons, furans, phenols, organic acids, and small quantities of insole alkaloid (fi-carbolines), harmane and norharmane.
Copper and iron ions can act as catalysts in the formation of compounds such as pyrazines
and pyridines, which are precursors of heterocyclic compounds (Parihar, Vasundhara & Vijayayaghavan, 1981; Jagerstad, Skog, Arvidsson & Solyakov, 1998).
Main compounds of interest include, acids, alcohols, ketones, aldehydes, lactones, esters, sulphur, phenols, benzene compounds, terpenes, alkanes, alkenes, thiols, thiol esters, pyrazines
, furans, amines and others.
"What we found," says Hillel Alpert, "is that they added ingredients--particularly pyrazines--that appear to have contributed to the 'smooth' flavor, reducing the harshness of certain cigarettes." Pyrazines
are also being added to e-cigarette fluids, his team wrote online June 10 in Tobacco Control.
However, beets contain substances as geosmin and pyrazines
which are responsible for the off flavor (ground) in this culture (STINTZING & CARLE, 2004).
Hashim and Chaveron  and Cros and Jeanjean  have suggested that during the drying of fermented cocoa beans, reducing sugars participate in non-enzymatic browning reactions (Maillard reactions) to form volatile fractions of pyrazines
. Oberparleiter and Ziegleder  have confirmed earlier findings by Hashim and Chaveron  and Cros and Jeanjean  by identifying Amadori compounds, the first intermediates of Maillard reaction in dried, unroasted cocoa beans.
A group of chemical compounds called methoxypyrazines (just "pyrazines
" will do) that occur in this family of red varieties give these wines an herbaceous quality that's magical with the foresty combo of rosemary and fresh horseradish.
The volatile collections from males and the synthetic pyrazines
were analysed by a gas chromatography/mass spectrometry detector, according to Robledo and Arzuffi (2012).