Yaylayan Varoujan A, Machiels David, Istasse Louis
Department of Food Science and Agricultural Chemistry, McGill University, 21111 Lakeshore, Ste. Anne de Bellevue, Quebec, Canada, H9X 3V9.
J Agric Food Chem. 2003 May 21;51(11):3358-66. doi: 10.1021/jf034037p.
One of the main shortcomings of the information available on the Maillard reaction is the lack of knowledge to control the different pathways, especially when it is desired to direct the reaction away from the formation of carcinogenic and other toxic substances to more aroma and color generation. The use of specifically phosphorylated sugars may impart some elements of control over the aroma profile generated by the Maillard reaction. Thermal decomposition of 1- and 6-phosphorylated glucoses was studied in the presence and absence of ammonia and selected amino acids through pyrolysis/gas chromatography/mass spectrometry using nonpolar PLOT and medium polar DB-1 columns. The analysis of the data has indicated that glucose-1-phosphate relative to glucose undergoes more extensive phosphate-catalyzed ring opening followed by formation of sugar-derived reactive intermediates as was indicated by a 9-fold increase in the amount of trimethylpyrazine and a 5-fold increase in the amount of 2,3-dimethylpyrazine, when pyrolyzed in the presence of glycine. In addition, glucose-1-phosphate alone generated a 6-fold excess of acetol as compared to glucose. On the other hand, glucose-6-phosphate enhanced retro-aldol reactions initiated from a C-6 hydroxyl group and increased the subsequent formation of furfural and 4-cyclopentene-1,3-dione. Furthermore, it also stabilized 1- and 3-deoxyglucosone intermediates and enhanced the formation of six carbon atom-containing Maillard products derived directly from them through elimination reactions such as 1,6-dimethyl-2,4-dihydroxy-3-(2H)-furanone (acetylformoin), 2-acetylpyrrole, 5-methylfurfural, 5-hydroxymethylfurfural, and 4-hydroxy-2,5-dimethyl-3-(2H)-furanone (Furaneol), due to the enhanced leaving group ability of the phosphate moiety at the C-6 carbon. However, Maillard products generated through the nucleophilic action of the C-6 hydroxyl group such as 2-acetylfuran and 2,3-dihydro-3,5-dihydroxy-4H-pyran-4-one were retarded, due to the blocked nucleophilic atom at C-6.
美拉德反应现有信息的主要缺点之一是缺乏控制不同反应途径的知识，特别是当希望引导反应远离致癌物质和其他有毒物质的形成，转向更多香气和色泽生成时。使用特定的磷酸化糖可能会对美拉德反应产生的香气特征提供一些控制因素。通过热解/气相色谱/质谱联用技术，使用非极性PLOT柱和中极性DB-1柱，研究了在有无氨和选定氨基酸存在的情况下，1-磷酸葡萄糖和6-磷酸葡萄糖的热分解情况。数据分析表明，与葡萄糖相比，1-磷酸葡萄糖在甘氨酸存在下热解时，会发生更广泛的磷酸催化开环反应，随后形成糖衍生的反应中间体，这表现为三甲基吡嗪的量增加了9倍，2,3-二甲基吡嗪的量增加了5倍。此外，单独的1-磷酸葡萄糖产生的丙酮醇比葡萄糖多6倍。另一方面，6-磷酸葡萄糖增强了由C-6羟基引发的逆羟醛反应，并增加了随后糠醛和4-环戊烯-1,3-二酮的形成。此外，它还稳定了1-脱氧葡萄糖酮和3-脱氧葡萄糖酮中间体，并通过消除反应增强了直接由它们衍生的含六个碳原子的美拉德产物的形成，如1,6-二甲基-2,4-二羟基-3-(2H)-呋喃酮（乙酰基乙偶姻）、2-乙酰基吡咯、5-甲基糠醛、5-羟甲基糠醛和4-羟基-2,5-二甲基-3-(2H)-呋喃酮（菠萝酮），这是由于C-6碳上磷酸部分的离去基团能力增强。然而，由于C-6处亲核原子被阻断，通过C-6羟基的亲核作用产生的美拉德产物，如2-乙酰基呋喃和2,3-二氢-3,5-二羟基-4H-吡喃-4-酮受到了抑制。
