Department of Organic Chemistry, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, B-9000 Ghent, Belgium.
J Agric Food Chem. 2010 Feb 24;58(4):2470-8. doi: 10.1021/jf903898t.
Whereas most studies concerning the Maillard reaction have focused on free amino acids, little information is available on the impact of peptides and proteins on this important reaction in food chemistry. Therefore, the formation of flavor compounds from the model reactions of glucose, methylglyoxal, or glyoxal with eight dipeptides with lysine at the N-terminus was studied in comparison with the corresponding free amino acids by means of stir bar sorptive extraction (SBSE) followed by GC-MS analysis. The reaction mixtures of the dipeptides containing glucose, methylglyoxal, and glyoxal produced 27, 18, and 2 different pyrazines, respectively. Generally, the pyrazines were produced more in the case of dipeptides as compared to free amino acids. For reactions with glucose and methylglyoxal, this difference was mainly caused by the large amounts of 2,5(6)-dimethylpyrazine and trimethylpyrazine produced from the reactions with dipeptides. For reactions with glyoxal, the difference in pyrazine production was rather small and mostly unsubstituted pyrazine was formed. A reaction mechanism for pyrazine formation from dipeptides was proposed and evaluated. This study clearly illustrates the capability of peptides to produce flavor compounds that can differ from those obtained from the corresponding reactions with free amino acids.
虽然大多数关于美拉德反应的研究都集中在游离氨基酸上，但关于肽和蛋白质对食品化学中这一重要反应的影响的信息却很少。因此，通过搅拌棒吸附萃取（SBSE）和 GC-MS 分析，研究了模型反应（葡萄糖、甲基乙二醛或乙二醛与 8 种以赖氨酸为 N 末端的二肽）中风味化合物的形成，与相应的游离氨基酸进行了比较。含葡萄糖、甲基乙二醛和乙二醛的二肽反应混合物分别产生了 27、18 和 2 种不同的吡嗪。一般来说，与游离氨基酸相比，二肽产生的吡嗪更多。对于葡萄糖和甲基乙二醛的反应，这种差异主要是由于二肽反应产生了大量的 2,5(6)-二甲基吡嗪和三甲基吡嗪。对于乙二醛的反应，吡嗪生成的差异较小，主要形成未取代的吡嗪。提出并评价了二肽形成吡嗪的反应机制。这项研究清楚地说明了肽产生风味化合物的能力，这些化合物可能与游离氨基酸相应反应得到的化合物不同。
