31105-03-0Relevant articles and documents
Formation of aroma-active Strecker-aldehydes by a direct oxidative degradation of Amadori compounds
Hofmann, Thomas,Schieberle, Peter
, p. 4301 - 4305 (2000)
α-Dicarbonyls, generated by sugar degradation, catalyze the formation of the so-called Strecker aldehydes from α-amino acids. To check the effectiveness of Amadori compounds (suggested as important intermediates in α-dicarbonyl formation from carbohydrates) in Strecker aldehyde formation, the amounts of phenylacetaldehyde (PA) formed from either an aqueous solution of L-phenylalanine/glucose or the corresponding Amadori compound N-(1-deoxy-D-fructosyl-1-yl)-L-phenylalanine (ARP-Phe) were compared. The results revealed the ARP-Phe as a much more effective precursor in PA generation. On the contrary, a binary mixture of glucose/phenylalanine yielded preferentially phenylacetic acid, in particular, when reacted in the presence of oxygen and copper ions. Further model experiments gave evidence that a transition-metal-catalyzed oxidation of the ARP-Phe by air oxygen into the 2-hexosulose-(phenylalanine) imine is the key step responsible for the favored formation of phenylacetaldehyde from the Amadori compound. This mechanism might explain differences in the ratios of Strecker aldehydes and the corresponding acids depending on the structures of carbohydrate degradation products involved.
Analysis of Amadori compounds by high-performance cation exchange chromatography coupled to tandem mass spectrometry
Davidek, Tomas,Kraehenbuehl, Karin,Devaud, Stephanie,Robert, Fabien,Blank, Imre
, p. 140 - 147 (2007/10/03)
High-performance cation exchange chromatography coupled to tandem mass spectrometry or electrochemical detection was found to be an efficient tool for analyzing Amadori compounds derived from hexose and pentose sugars. The method allows rapid separation and identification of Amadori compounds, while benefiting from the well-known advantages of mass spectrometry, such as specificity and sensitivity. Glucose- and xylose-derived Amadori compounds of several amino acids, such as glycine, alanine, valine, leucine/isoleucine, methionine, proline, phenylalanine, and glutamic acid, were separated or discriminated using this new method. The method is suitable for the analysis of both model reaction mixtures and food products. Fructosylglutamate was found to be the major Amadori compound in dried tomatoes (~1.5 g/100 g) and fructosylproline in dried apricots (~0.2 g/100 g). Reaction of xylose and glycine at 90 °C (pH 6) for 2 h showed rapid formation of xylulosylglycine (~12 mol %, 15 min) followed by slow decrease over time. Analysis of pentose-derived Amadori compounds is shown for the first time, which represents a major breakthrough in studying occurrence, formation, and decomposition of these labile Maillard intermediates.