Amyl alcohols as compounds indicative of raw cocoa bean quality

The aroma quality of raw cocoa beans mainly depends on the fermentation degree because the necessary aroma precursors are developed during fermentation. Additional influences arise from drying and storage of cocoa beans. Gas chromatograms of steam distillates of cocoa beans were analysed to identify significant key compounds. Major components are methyl-butanals and methyl-butanols. Although they are not specific flavour constituents, amyl alcohols obviously are useful key compounds. They are significantly altered during fermentation and longer storage periods of raw cocoa beans. The concentration of methyl-1-butanols increases during fermentation or decreases in beans that have been stored for several years. Therefore, their concentration indicates the fermentation degree if it is compared to the level of 3-methyl-2-butanol, which remains independent of the fermentation processes.