The Precursors of Chocolate Aroma: The distribution of free amino acids in different commercial varieties of cocoa beans

Abstract

SUMMARY A study of the distribution of the free amino acids in different commercial varieties of cocoa beans revealed differences which might account, at least in part, for the acknowledged variations in aroma and flavor of the products obtained from these raw materials.

The Precursors of Chocolate Aroma: Changes in the Free Amino Acids During the Roasting of Cocoa Beans

“…The free amino acids of cocoa beans have already been shown to constitute one of the major components of the precursors of chocolate aroma (Rohan, 1963(Rohan, , 1964) and there is also some evidence (Rohan and Stewart, 1965) that the amino acids are responsible, in part, for the auxiliary aroma of chocolate. Changes which occur in these constituents of cocoa beans, during roastin?, are consequently of some importance.…”

“…A replicate roast was carried out and sampled likewise. The roasts and samples were those described in a previous publication (Rohan and Stewart, 1965).…”

“…This was effected by paper chromatographic separation of the amino acids into groups and spectrophotometric estimation of the ninhydrin complexes, as previously described (Rohan and Stewart, 1965).…”

Structural and chemical changes in cocoa (Theobroma cacao L) during fermentation, drying and roasting

“…4,5 During processing, proteolysis, especially that of the globulin fraction, produces peptides and amino acids that contribute directly to the¯avour of cocoa 6 and to the Maillard reaction during roasting, the pro®le and the process conditions being more responsible for a good¯avour than the total amounts of these components. 7,8 The oxidation, condensation and complexation of polyphenolics contribute to the astringency of the cocoa product, and these substances are involved in reactions leading to the formation of other compounds. 9,10 Additional substances, produced during fermentation and absorbed by the seeds, 2 include acetic acid which, in large amounts, may be detrimental to the quality of the cocoa product.…”

Precursors of typical and atypical roasted peanut flavor

“…Later t~e same group (20) showed that different varities of cocoa had c;lifferent aJnino acid concentrations and it was postulated that the differences in flavor between varieties arose from the variability in amino acid levels in the fermented bean.…”