Many foods are subject to browning by heat treatment or long storage times. Either if it is a sign of quality decrease or a desirable feature, it is necessary to characterize fully the color of what is perceived as “brown.” In this paper, we define three stages of browning in foods, ranging from yellow, reddish‐brown to dark brown, showing that the commonly employed indexes are not sufficient to describe the later stages of browning, corresponding to the darker colors. Frequently absorbance at a single wavelength, two‐dimensional (2D) diagrams, browning index depending on one chromatic coordinate or just L^* are employed to describe color in the browning processes in food systems. While these tools are adequate enough to define the evolution of the reaction, they fail to properly characterize the brown color quality: they evaluate either lightness (1D) or the chromatic aspects (2D). In this work, we fully characterized browning in 3D color spaces. The limits for the appropriate use of the different indexes were also defined, according to the browning stage.

中文翻译：

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食物中普遍存在的非酶褐变现象导致的颜色解释

许多食物会因热处理或较长的储存时间而变成褐色。无论是质量下降的标志还是期望的功能，都必须充分表征被认为是“棕色”的颜色。在本文中，我们定义了食品的褐变三个阶段，从黄色，红褐色到深褐色，这表明常用的指标不足以描述褐变的后期阶段，对应于较深的颜色。单一波长的频繁吸收，二维（2D）图，褐变指数取决于一个色坐标或仅取决于L ^*用于描述食品系统褐变过程中的颜色。尽管这些工具足以确定反应的进行，但它们无法正确表征棕色的质量：它们评估亮度（1D）或色度（2D）。在这项工作中，我们充分表征了3D颜色空间中的褐变。根据褐变阶段，还定义了适当使用不同索引的限制。