Recent Advances in the Chemistry of Strecker Degradation and Amadori Rearrangement: Implications to Aroma and Color Formation

Abstract

The importance of Strecker degradation lies in its ability to produce Strecker aldehydes and 2-aminocarbonyl compounds, both are critical intermediates in the generation of aromas during Maillard reaction, however, they can also be formed independently of the pathways established for Strecker degradation. Strecker aldehyde can be formed directly either from free amino acids or from Amadori products. Several pathways have been proposed in the literature for the mechanism of this transformation. On the other hand, Amadori or Heyns rearrangements of ammonia with reducing sugars can also generate 2-aminocarbonyl compounds without the formation of Strecker aldehyde. In addition, isomerization of the imine bond of the Schiff base formed between a reducing sugar and an amino acid, can initiate a transamination reaction and convert the amino acid into the corresponding ␣-keto acid and the sugar into its ␣-amino alcohol derivative. The reverse of this reaction, has been documented to produce Amadori products. The ␣-keto acids can either decarboxylate to produce Strecker aldehydes or undergo Strecker degradation (as a ␣-dicarbonyl compound) with amino acids to also produce Strecker aldehydes. This review will examine the role of Strecker degradation and Amadori rearrangement, under the light of recent findings, in controlling the balance among four critically important key intermediates: ␣-dicarbonyl, ␣-hydroxycarbonyl, 2-amino carbonyls and 2-(amino acid)-carbonyl compounds, during the Maillard reaction and hence control relative importance of aromagenic versus chromogenic pathways.

Precursors, Formation and Determination of Furan in Food

“…3). Glycolaldehyde on the other hand, can be generated through Strecker type reactions in the presence or absence of reducing sugars (Yaylayan, 2003). Similar pathways can be envisaged for cysteine.…”

Formation of α-dicarbonyl compounds in cookies made from wheat, hull-less barley and colored corn and its relation with phenolic compounds, free amino acids and sugars

“…α-Dicarbonyl compounds are responsible for glycation of several biomolecules in vivo [1]. Although having adverse effects on health, α-dicarbonyl compounds play an important role on flavor and browning development, which are desirable consequences of thermal processing of certain foods [3,4]. Therefore, studies about their formation, quantitation and elimination have a critical importance both in biochemical and food research.…”

Formation of the peptide-specific imidazolidin-4-one moiety in alanine containing Maillard reaction mixtures

“…2). However, at temperatures higher than 250°C, alanine alone can undergo oxidative decarboxylation (Yaylayan, 2003;Yaylayan & Keyhani, 2001) to form the imine shown in Fig. 5 the latter can hydrolyse into acetaldehyde thus providing the essential component for the formation of 3-ethyl-2,5-dimethylimidazolidin-4-ones.…”