Abstract
The subject of this research was an experimental study of the development of chocolate aroma during the commercial processing of cocoa beans. The components of unroasted aroma cocoa beans have been fractionated, and the various groups of substances obtained tested for the development of aroma when roasted. The results obtained provide further evidence of the involvement of simple amino acids, reducing sugars and flavonoids in the formation of the primary aroma of chocolate products, and a mechanism for the formation and mixing of these substances during cocoa fermentation is described. Model mixtures of these compounds have been examined in order to assess the extent of the contribution of individual compounds to the production of the aroma. The reaction of these model mixtures have also been examined under the conditions obtaining during commercial bean roasting, and combined gas chromstography-mase spectrometry has been used to compare their volatile reaction products with these present in roasted cocoa beans. The results of these studies indicate the importance of the natural environment of the precursors in the control of the extent of subsequent reactions, and the consequences of the 'dry state' reaction conditions in this respect. Various types of compound formed in these reactions are described and their possible importance in the recognition of chocolate aroma is discussed. The experimental results are discussed in terms of literature surveys of the current state of knowledge of both chocolate aroma development, and the aroma potential of amino acid-reducing sugar reactions.