2-Threityl-thiazolidine-4-carboxylic acid (TTCA), a nonvolatile precursor of flavor and color, is considered to be more stable than its isomeric Amadori compound (ARP). The degradation behavior of TTCA favors higher temperatures and pH. In order to adjust and control the thermal degradation of TTCA to improve its food processing adaptability, a TTCA–Xyl thermal reaction model was constructed to explore the effect of extra-added Xyl on the thermal degradation behavior of TTCA. The results confirmed that the extra-added Xyl was involved in the degradation pathway of TTCA and accelerated its depletion, thus promoting the formation of characteristic downstream products of TTCA including some α-dicarbonyl compounds, and consequently accelerating the browning formation. The isotope-labeling technique was further applied to confirm that the added Xyl could trap the Cys released from the decomposition of ARP and formed additional TTCA, which could promote the movement of chemical equilibrium and gradually accelerate the degradation rate of TTCA as well as melanoidins formation. The higher pH value could even promote this phenomenon.

中文翻译：

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美拉德反应中额外添加的木糖和释放的半胱氨酸之间的捕集反应加速了2-Threetyl-Thiazolidine-4-羧酸的降解及相应的褐变

2-三苯甲基-噻唑烷-4-羧酸 (TTCA) 是一种风味和颜色的非挥发性前体，被认为比其异构 Amadori 化合物 (ARP) 更稳定。TTCA 的降解行为有利于更高的温度和 pH 值。为了调节和控制TTCA的热降解，提高其食品加工适应性，构建了TTCA-Xyl热反应模型，探讨了额外添加的Xyl对TTCA热降解行为的影响。结果证实，额外添加的Xyl参与了TTCA的降解途径并加速了其消耗，从而促进了TTCA下游特征产物包括一些α-二羰基化合物的形成，从而加速了褐变的形成。进一步应用同位素标记技术证实添加的Xyl可以捕获ARP分解释放的Cys并形成额外的TTCA，从而促进化学平衡的运动，逐渐加快TTCA的降解速度以及类黑素的形成. 较高的pH值甚至可以促进这种现象。