Pyrazine 2.5- dimethyl-3-«-propyl

Table II lists the major volatile compounds from baked blanched and fried blanched shallot slices generated from thermal degradation of nonvolatile flavor precursors of shallot were methyl propyl trisulfide, dimeihylthiophencs, methyf propyl disulfide, and dipropy trisulfide. The major volatile compounds that were probably generated from ihemia imeractiuns of nonvolatile flavor precursors of shallot and sugars were pyrazines, especially ethyl dimethyl pyrazines, dimethyl-pyrazines, ethyl methyl pyrazines, and trimethylpyrazine.

The odor threshold of the pyrazines range from 0.006 ppb in water for 2—propyl—3-methoxypyrazine (29) to 43 ppm in water for 2,5—dimethyl—3-ethyl pyrazine (30). A excellent review of the pyrazines found in food products has been prepared by Maga (31). 

Dimethyl-3-ethyl-2-hydroxy-E9b/2, 268f, (Gloxal + H2N-CHR-CO-NH2) 2-Hydroxy-3-isopropyl-5-methyl-E9b/2, 268f. (H3C-CO-CHO + H2N-CHR-CO-NH2) 2-Hydroxy-5(or6)-methyl-3-propyl-E9b/2, 268 f. (H3C-CO-CHO -I- H2N-CHR-CO-NH2) Pyrazin-1,4-bis-oxid 2,5-Diethyl-E9b/2, 309 (N-Oxidat.) Pyrazin-l-oxid... 

Wood pyrazine 3-ethyl-2- methoxy- 2-ethoxy- 3,6-dimethyl-3-ethyl- 2-propyl- 2-butyl-3,5- dimethyl- 2-butyl-3,6- dimefhyl- 2- acetyl- 3- methyl- 2-acetyl-3,5- dimethyl- Total... 

Pyrazine, 3,5-dimethyl-2-propyl-, 3,5-dimethyl-2-propylpyrazine, 2,6-dimethyl-3-propylpyrazine [32350-16-6]... 

Potato flavor is greatly influenced by methods of cooking or preparation. Raw potato contains the characteristic earthy aroma component, 2-ixo-propyl-3-methoxypyrazine. A character impact compound common to boiled and baked potatoes is methional (3-[methylthio]propanal). Baked potatoes contain Maillard products such as 2-ethyl-3-methylpyrazine (earthy, nutty) and 2-ethyl-6-vinylpyr-azine (buttery, baked potato) (34). In potato chips and French-fried potatoes, the potato flavor character of methional is modified by volatile aromatics from frying oils, such as ( , )-2,4-decadienal, and thermally generated alkyl oxazoles possessing lactone-like flavors (34,39). The pyrazines 2-ethyl-3,5-dimethyl and 2,3-diethyl-5-methylpyrazine are described as potato chip like (40). 

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