Volatile browning flavors, characteristics

The research on coffee chemistry has been particularly active during the last 50 years and the scientific literature on the subject is extensive. The content of this monograph is limited to the identification and the characteristics of the compounds present in the volatiles of green and roasted coffees. The mechanisms of formation of the flavor during roasting will not be extensively developed, the browning reactions... 

Fattee et al. ( ) isolated and identified the volatiles of "normal-flavored" raw peanuts. They found pentane, acetaldehyde, methanol, acetone, ethanol, and hexanal as major components and methyl formate, octane, 2-butanone, and pentanal as minor components. The characteristic aroma and flavor of raw peanuts were suggested to arise from a physical interaction of the components Isolated, with hexanal the most significant contributor to this aroma. Brown et al. (J ) isolated the aldehydes and ketones from raw peanuts as their 2,4-dinitro-phenylhydrazones. Concentrations of hexanal and octanal exceeded their flavor thresholds. The concentration data suggested that in addition to hexanal, octanal and possibly nonanal and 2-nonenal contribute to the "green or beany" flavor of raw peanuts. 

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