Pyrazine/pyridine

Not listed and therefore not permitted are substances from chemical groups like pyrazines, pyridines, amines, amides, or aliphatic lower alcohols, aldehydes and hydrocarbons (C5 and lower) if not mentioned by individual name [17]. 

Heterocyclic compounds are primarily formed through non-enzymatic browning reactions. Recent studies of deep-fat fried food flavors led to the identification of pyrazines, pyridines, thiazole, oxazoles and cyclic polysulfides which had long-chain alkyl substitutions on the heterocyclic ring. The involvement of lipid or lipid decomposition products in the formation of these compounds could account for the long-chain alkyl substitutions. Model systems were used to study the participation of lipids in the formation of pyrazines, pyridines, thiophenes and cyclic polysulfides. 

Food, flavors consist of numerous compounds, none of which alone is characteristic of specific food. Classes of compounds which emcompass food flavors are - hydrocarbons (aliphatic, ali-cyclic, aromatic) carbonyls (aldehydes, ketones) carboxylic acids, esters, imides, anhydrides alcohols, phenols, ethers alkylamines, alkylimines aliphatic sulfur compounds (thiols, mono-, di- and tri-sulfides) nitrogen heterocyclics (pyrroles, pyrazines, pyridines) sulfur heterocylics (thiophenes, thiazoles, trithiolane, thialidine) and oxygen-heterocyclics (lactone, pyrone, furan). Discussion will be limited to striking developments in heterocyclics. 

A starch-glycine mixture, heated at 290°C, was significantly different from the starch control in its composition of alkoxyphenols and imidazoles in the involatile phase, and pyrazine, pyridine, methylpyridine, and dimeth-ylpyrroles in the volatile phase (Umano and Shibamoto, 1984). The neurotoxin 4(5)-methylimidazole appeared in the vapor phase when ammonia, but not amino acids, was the nitrogen source (Tomasik et al., 1989b). A corn starch-sucrose combination inhibited the Maillard reaction (Lee and Woo, 1988). 

Heterocyclic compounds, such as furans, pyrazines, pyridines, and thiazoles... 

Anilines, pyrazines, pyridines, pyrroles, tobacco-specific N- nitrosamines, etc. 

The Maillard reaction between reducing sngars and amino acids under specific conditions (pH, water activity, and temperature) is primarily responsible for the production of heterocyclic volatile compounds such as pyrazines, pyridines, pyrroles, furans, and the Strecker aldehydes. Maillard reactions produce many potent aroma compounds identified in some roasted tree nuts, including 3-methylbutanal, 2,3-butanedione, methional, phenylacetaldehyde, 2-ethyl-3,5-dimethylpyrazine, and 2,5-dimethyl-4-hydroxy-3(2//)-furanone, among others. 

Propyl tiglate Pulegone d-Pulegone Pyrazine Pyridine... 

Intervalence transfer in the solid phase with ion pair systems of the type [Ru(III)(NH3)6][Fe(II)(CN)5L] where L is CO, CN, DMSO, pyrazine, pyridine, or imidazole is strongly dependent on the nature of L. A linear correlation between op and the difference in redox potential of the component ions... 

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