Cerny Christoph
Firmenich Corporate R&D Division, CH-1217 Meyrin 2 Geneva, Switzerland.
Ann N Y Acad Sci. 2008 Apr;1126:66-71. doi: 10.1196/annals.1433.011. Epub 2007 Dec 13.
The Maillard reaction in food produces, among others, a diversity of sensory-active compounds (aroma, taste, color). The resulting key aroma compounds are often present only in trace concentrations of 1 microg/kg to 1 mg/kg. Nevertheless, they contribute to the respective flavor because of their low odor-perception thresholds. While Maillard intermediates, such as Amadori compounds and deoxyosones, are formed at percentage levels during model reactions, the yield of aroma compounds, in particular nitrogen and sulfur-containing ones, is often as low as 0.001-0.01 mol%, thus indicating their formation through chemical side reactions. The elucidation of the relevant precursors in food and the identification of previously unknown intermediates can throw light on these minor pathways. Also, model reactions with isotopically labeled precursors are of great value in gaining insight into the relevant formation mechanisms. Several examples of these studies are illustrated including work to elucidate the role of the solvent glycerol in the formation of pyrazines, trials to reveal the relative significance of 4-hydroxy-5-methyl-3(2H)-furanone as intermediate in the reaction between ribose and cysteine, and experiments to assess the proportional contribution of the precursors cysteine, xylose, and thiamine to the formation of the resulting aroma compounds in the thermal reaction.
食物中的美拉德反应会产生多种具有感官活性的化合物（香气、味道、颜色）。生成的关键香气化合物通常仅以痕量浓度存在，范围为1微克/千克至1毫克/千克。然而，由于它们的低气味感知阈值，它们对各自的风味有贡献。虽然在模型反应中，美拉德中间体，如阿马多里化合物和脱氧酮，是以百分比水平形成的，但香气化合物的产率，特别是含氮和含硫的香气化合物，通常低至0.001 - 0.01摩尔%，这表明它们是通过化学副反应形成的。阐明食物中的相关前体以及鉴定以前未知的中间体可以揭示这些次要途径。此外，使用同位素标记前体的模型反应对于深入了解相关形成机制具有重要价值。文中列举了这些研究的几个例子，包括阐明溶剂甘油在吡嗪形成中的作用的工作、揭示4 - 羟基 - 5 - 甲基 - 3(2H)-呋喃酮作为核糖与半胱氨酸反应中间体的相对重要性的试验，以及评估前体半胱氨酸、木糖和硫胺对热反应中生成的香气化合物形成的比例贡献的实验。
