The shift from artificial to natural ingredients is a rising trend in the food industry. However, natural coloring agents tend to be less stable than their synthetic counterparts when exposed to light, air, changes in pH, and heat. This study compares the photostability of three organic red dyes, Red 40 (allura red AC), betanin and carminic acid, in aqueous and soft drink solutions. The degradation, traced through absorbance spectroscopy, is well fit to first-order kinetics. Two distinct timescales are observed in aqueous solution but only a single, faster decay in the soft drink matrix. Betanin is the least stable dye in both solvent environments and Red 40 exhibits the greatest destabilization in the soft drink solution. Anoxia has different impacts dependent upon both the dye and solvent system. The analysis provides further insight into the degradation mechanisms for these different red dyes and the role of environment on their photostability.

中文翻译：

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有机红色食用染料的光稳定性。

从人工成分到天然成分的转变是食品工业中的一种上升趋势。然而，当暴露于光，空气，pH值变化和热时，天然着色剂往往不如其合成稳定剂稳定。这项研究比较了三种有机红色染料Red 40（阿鲁拉红AC），甜菜碱和胭脂红酸在水溶液和软饮料溶液中的光稳定性。通过吸光度光谱追踪的降解非常适合一阶动力学。在水溶液中观察到两个不同的时间尺度，但是在软饮料基质中只有一个更快的衰减。在两种溶剂环境中，甜菜碱都是最不稳定的染料，而Red 40在软饮料溶液中表现出最大的失稳性。取决于染料和溶剂系统，缺氧会产生不同的影响。