水相体系中美拉德反应中间体的制备研究

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摘要：Maillard 反应是氨基酸的氨基与还原糖的羰基发生的缩合反应，不同条件下，Maillard 反应可以产生具有不同香气、不同香气特征的香物质。Amadori 化合物是 Maillard 反应过程中的中间产物，是重要的不挥发的致香前体物质。48979

本课题以半胱氨酸为示踪剂的水相中间体可控制备及其表征，在水相体系中，用半胱氨酸作为示踪剂，采用二阶段变温美拉德反应方法制备葡萄糖-蛋氨酸中间体，对不同体系，采用LC-MS及LC-MS/MS对反应液中的Amadori化合物进行鉴定分析得出水相体系中 Amadori 中间体形成的最佳反应条件为将蛋氨酸溶于水中配制成饱和溶液，再将葡萄糖溶于其中，蛋氨酸与葡萄糖以质量比1:2均匀混合，用缓冲溶液调节反应液的PH至7.4，置于美拉德反应瓶中，同时放入搅拌子搅拌（10r/min），密封后置于100℃油浴锅中反应80min。确定其相对分子质量为311，化学式为C11H21NO7S，并推测了Amadori化合物的合成反应方程式。

采用葡萄糖-蛋氨酸体系在 PH7.4、温度在100℃下分别反应10、20、40、60、80、100、120min，考察反应液A420、A294以及反应液PH随反应时间的变化，发现随着反应时间的增加，A420逐渐增大，表明褐变程度随着时间的增加而增加。A294也随时间的增加而增大，但在20-80min之间，增加幅度比较大，在80-120min之间增加幅度比较小，基本趋于平缓，表明在反应的前期，中间体形成的速度比较快，超过100min时，反应逐渐减慢。体系的PH随着反应时间的增加而下降，在100min之后下降幅度逐渐减小，基本趋于稳定。

运用GC-MS联用技术对其产物进行鉴定分析，不同临界条件下形成的 Amadori 化合物热解产物不同。热解产物主要为烃类、醇类、醛类、酸类、酯类、酮类、醚类、吡嗪类、呋喃、呋喃酮、吡唑、吡咯、吡喃酮等化合物，其中部分结构直接可以反映出 Amadori 化合物中糖跟氨基酸的结构，这些产物是食品及卷烟烟气中重要的致香成分。

毕业论文关键词：Maillard 反应中间体；合成；动力学；热解

Preparation of the aqueous phase system Maillard reaction intermediate

Abstract: Maillard reaction is a condensation reaction with the amino carbonyl amino sugar that occurs, under different conditions, Maillard reaction can produce substances with different flavor aroma, different aroma characteristics. Amadori compounds are Maillard reaction intermediate product, it is important not volatile aroma precursors.

The issue of water as a tracer cysteine intermediate phase controllable Preparation and Characterization, in an aqueous system, cysteine as a tracer, using warm Maillard reaction process for preparing the second phase of glucose change - methionine intermediates for different system, using LC-MS and LC-MS / MS in the reaction mixture of Amadori compounds forensic analysis optimum reaction conditions aqueous systems Amadori intermediates formed is formulated methionine dissolved in water into a saturated solution, and then dissolved therein dextrose, glucose and methionine mass ratio of 1: 2 were uniformly mixed, the reaction solution was adjusted with a buffer solution of PH 7.4, pressure temperature into the reaction flask, simultaneously into stir stirring (10r / min), sealed and placed in an oil bath at 100℃ pot reaction 80min. Determine the relative molecular mass of 311, the formula C11H21NO7S, and presumably the Amadori compound synthesis reaction equation.

Using glucose - Met system in PH7.4, at a temperature of 100℃, respectively reaction 10,20,40,60,80,100,120min, change the time of reaction solution A420, A294 and the reaction liquid PH with reaction, with the discovery reaction time increases, A420 increases, indicating the degree of browning increase over time increases. A294 is also increased with the increase of time, but in between 20-80min, the rate of increase is relatively large, between 80-120min rate of increase is relatively small, basically leveled off, indicating that the rate in the early reaction intermediate formed faster, more than 100min, the reaction gradually slowed down. PH system with increasing reaction time and decreased gradually decreases decline after 100min, basically stabilized.