Hello! I'm Dr. Olivia, a food scientist specializing in emulsion science. You're asking a fascinating question about the color of mayonnaise. While it might seem simple, the answer lies in the complex interplay of ingredients and their interactions.

Let's break down why mayonnaise appears white:

1. The Nature of Emulsions: Mayonnaise is an emulsion, a mixture of two immiscible liquids (in this case, oil and water) where one liquid is dispersed throughout the other. This means tiny droplets of oil are suspended in a continuous phase of water, stabilized by an emulsifier, in this case, egg yolks.

2. The Role of Egg Yolks: Egg yolks contain lecithin, a powerful emulsifier that can bind both oil and water molecules. This allows the oil droplets to be evenly distributed throughout the water, preventing them from coalescing and separating.

3. Light Scattering: The tiny oil droplets in mayonnaise are much smaller than the wavelength of visible light. When light hits these droplets, it undergoes a phenomenon called Rayleigh scattering. In this process, light is scattered in all directions, resulting in a diffuse, white appearance.

4. The Role of Color: The ingredients themselves don't inherently contribute much color to mayonnaise. The oil is typically clear, the vinegar is colorless, and while egg yolks have some yellow pigment, it's relatively subtle in comparison to the scattering effect.

5. Variations in Appearance: While mayonnaise is usually white, subtle variations can occur due to factors like:

* Fat Content: Mayonnaise with higher fat content might appear slightly creamier due to the increased scattering of light by the larger oil droplets.
* Ingredient Variations: Using different types of oil, such as olive oil, can introduce subtle color variations due to the oil's natural hue.

**In summary, the white color of mayonnaise is primarily due to the scattering of light by the tiny oil droplets suspended in the water, a consequence of its emulsion structure. The presence of the emulsifier, lecithin, is crucial for stabilizing this emulsion and achieving the characteristic white color.**

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中文翻译:

大家好！我是奥利维亚博士，一位专门研究乳化科学的食品科学家。你问了一个关于蛋黄酱颜色的有趣问题。虽然它看起来很简单，但答案在于成分及其相互作用的复杂相互作用。

让我们来分解一下为什么蛋黄酱看起来是白色的：

1. 乳化液的性质：蛋黄酱是一种乳化液，是两种互不相溶的液体（在本例中是油和水）的混合物，其中一种液体分散在另一种液体中。这意味着油的小液滴悬浮在水的连续相中，并由乳化剂稳定，在本例中是蛋黄。

2. 蛋黄的作用：蛋黄含有卵磷脂，这是一种强大的乳化剂，可以结合油和水分子。这使得油滴能够均匀地分布在水中，防止它们聚结和分离。

3. 光散射： 蛋黄酱中的油滴比可见光的波长小得多。当光照射到这些液滴时，它会发生一种叫做瑞利散射的现象。在这个过程中，光向各个方向散射，从而产生漫射的白色外观。

4. 颜色的作用： 成分本身并没有给蛋黄酱带来多少颜色。油通常是透明的，醋是无色的，虽然蛋黄有一些黄色色素，但与散射效果相比，它相对微妙。

5. 外观变化： 虽然蛋黄酱通常是白色的，但由于以下因素，可能会出现细微的变化：

* 脂肪含量：脂肪含量较高的蛋黄酱可能看起来稍微更奶油一些，因为较大的油滴增加了光的散射。
* 成分变化： 使用不同类型的油，例如橄榄油，会由于油的天然色调而产生细微的颜色变化。

**总之，蛋黄酱的白色主要是因为悬浮在水中的微小油滴散射了光，这是其乳化结构的结果。乳化剂卵磷脂的存在对于稳定这种乳化液并实现其特有的白色至关重要。**read more >>

Mainly the reason is that store mayonnaise adds water, rather than relying on the moisture in the egg yolks and vinegar. ... Though cookbooks often say that the ratio of oil to egg yolk is critical, that one can only emulsify a half-cup or cup of oil, this isn't true.read more >>