Concentrations of some aliphatic aldehydes and ketones found in raw and roasted spanish and runner peanuts

Abstract Carbonyl compounds in oil cold‐pressed from raw and roasted peanuts were isolated and quantitated as their 2,4‐dinitrophenylhydrazones. Quantitative data were obtained for more than 40 compounds and compared to the flavor threshold values of the compounds in oil. In general, concentrations of aldehydes and ketones in Spanish peanuts were higher than in runner peanuts. Hexanal and octanal and possibly nonanal, 2‐octenal and 2‐nonenal may contribute to the “green‐beany” flavor of raw peanuts. Concentrations of 2‐methylpropanal, 2‐methylbutanal and 3‐methylbutanal vastly exceeded their flavor thresholds and probably contribute significantly to the harsh note of freshly roasted peanuts. Other compounds that could contribute to the flavor and aroma of roasted peanuts are: hexanal, heptanal, octanal, nonanal, dodecanal, 2‐heptenal, 2‐octenal, 2‐nonenal, 2‐decenal and 2,4‐decadienal.