Maillard reactions have been reported extensively. However, full color development kinetics of Maillard reactions have rarely been studied in detail. This study systematically investigated the color development kinetics of Maillard reactions. Thus, arginine (Arg), histidine (His), and lysine (Lys) were each reacted with dihydroxyacetone (DHA) using a simplified model system at different molar ratios, reaction times, pH, and temperatures. Importantly, the browning intensity (at 450 nm) and full color characteristics (within CIE L*a*b* color space) were measured and analyzed in detail. Minitab statistical software was employed to design the factorial experiments and analyze the main and interaction effects. It was found, for the first time, that His and Lys reacted with DHA more rapidly than Arg, and the difference was obvious with the increase of molar ratio and reaction time, reflected in the change of b*. pH 6.2 and higher temperature favored the formation of deeper colored products in amino acid–DHA, accompanied by reduced lightness (L*), significant loss in yellow hues (+b*), and shift toward red hues (+a*). The greatest browning intensities of Arg–DHA (A₄₅₀ = 0.63), His–DHA (A₄₅₀ = 1.12), and Lys–DHA (A₄₅₀ = 1.18) were achieved at molar ratio = 3, 72 h, pH 6.2, and 50 °C, with corresponding L*, a*, and b* values being 54.51, 14.03, 42.75; 48.26, 47.28, 13.59; and 43.35, 53.64, 10.82, respectively.

中文翻译：

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美拉德反应的显色动力学

美拉德反应已被广泛报道。然而，很少对美拉德反应的全色显影动力学进行详细研究。这项研究系统地研究了美拉德反应的显色动力学。因此，使用简化的模型系统，在不同的摩尔比，反应时间，pH和温度下，精氨酸（Arg），组氨酸（His）和赖氨酸（Lys）分别与二羟基丙酮（DHA）反应。重要的是，褐变强度（在450 nm处）和全色特性（在CIE L * a * b内）*颜色空间）进行了详细的测量和分析。使用Minitab统计软件设计析因实验并分析主要影响和交互作用。首次发现His和Lys与DHA的反应比Arg更快，并且随着摩尔比和反应时间的增加，其差异明显，反映在b *的变化上。pH 6.2和较高的温度有助于在氨基酸-DHA中形成更深的着色产物，并伴有亮度降低（L *），黄色调（+ b *）显着损失以及向红色调（+ a *）转移。Arg–DHA（A ₄₅₀ = 0.63），His–DHA（A ₄₅₀）的最大褐变强度= 1.12）和Lys–DHA（A ₄₅₀ = 1.18）在摩尔比= 3、72 h，pH 6.2和50°C时达到，相应的L *，a *和b *值分别为54.51、14.03， 42.75；48.26、47.28、13.59；和43.35、53.64、10.82。