Aroma Compounds from Amino Acid Metabolism

2 Aroma Compounds from Amino Acid Metabolism 

Amino acid metabolism generates aromatic, aliphatic, and branched chain alcohols, acids, carbonyls, and esters that are important to the flavor of fruit. Yu et al. [20-22] were amongst the earliest researchers to demonstrate that valine, leucine, alanine, and aspartic acid can be converted to short chain carbonyls by tomato extracts. The enzymes involved in these transformations were found to be located in different sites in the tomato. The soluble tomato fraction isolated via centrifugation acted on leucine while the mitochondrial fraction metabolized both alanine and aspartic acid. The 

Propyl, Butyl and Hexyl trans-2, cis-4 Decadienoate 

FIGURE 4.3 Proposed pathway for the production of unsaturated esters in peats, El = A3cis-A2trans-enoyl-CoA isomerase E2 = Acyl-CoA dehydrogenase. (From Tressl, R., M. Holzer, M. Apetz, Aroma Research, H. Maarse, PJ. Groenen, Eds., Wageningen, Netherlands, 1975, p. 41. With permission.) 

FIGURE 4.4 Proposed pathway for the formation of short chain carbonyls by enzymatic degradation of acyl lipids in disrupted tomato fruits. (From Galliard, R, J.A. Matthew, A.J. Wright, M.J. Fishwick, J. Sci. Food Agric., 28, p. 863, 1977. With permission.) 

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Formation of aroma compounds from lipid and amino acid metabolism is described. 

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