Hashim and Chaveron  and Cros and Jeanjean  both 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
This problem was overcome by stimulating males by exposure to papaya, to increase the quantities of both pyrazines
(Robledo & Arzuffi 2012).
This eventually produces many important classes of flavour compounds including furans, pyrazines
, pyrroles, oxazoles, thiophenes, thiazoles and other heterocyclic compounds (Figure 5; Melton, 1999).
Of these, pyrazines
and pyridines have the greatest aromatic contribution and are responsible for the distinct maize/nutty aromas found in coffee.
Formation of Strecker aldehydes and pyrazines
in a fried potato model system.
Additionally, Treattazine contains a variety of other natural odiferous molecules and methoxy pyrazines
The second-largest group, the pyrazines
, contribute to the toasted flavours.
The book contains six chapters covering synthesis, reactions and applications in the following subject areas: pyridazines, cinnolines, benzocinnolines and phthalazines; pyrimidines and quinazolines; pyrazines
and related ring structures; phenzine, oxazine, thiazine and sulphur dyes; quinazoline alkaloids; six-membered rings with three or more hetero-atoms.
It judges negative aromas like green pyrazines
, positive aromas like red, black or jammy fruit, along with mouth-feel and correlates it all to pricing.
But the total amount of the two 2-acyl-1-pyrrolines and two pyrazines
should not exceed 400 micrograms per kilogram to avoid an over-roasted aroma.
1996); and 2,3-butanediol, acetic acid, benzene acetaldehyde and pyrazine
2,6-dimethyl, maltol, pyrazines
, 1-octen-3-ol which were described as the major odor--active compounds in fermented soybean (Lee and Ahn, 2009; Zhao et al.
The compounds released by these species have been identified as lactones, monoterpenes, sesquiterpenes, alcohols, esters, pyrazines
, and aldehydes (Landolt & Averill 1999; Heath et al.