Why Is Milk White?
The more you know.
By Sadho Ram
Milk — the primary source of nutrition for the mammalian infants outside the womb — needs no introduction.
Still, it is an opaque white fluid that's rich in fat and protein.
This bovine juice has 87% water and 13% solids, like fat, proteins, lactose, vitamins and minerals. Of the 13%, about 5% is lactose, 3.7% is fats, and 3.5% proteins.
But ever wonder why is milk white?
The whiteness of milk is due to the scattering of light by the colloidal particles of the milk emulsion. Basically, the fats and proteins in milk are what give it the white colour.
Chief among these proteins is casein, four types of which make up about 80% of the proteins in milk. Casein is calcium-rich and is the most common protein found in milk.
These casein proteins and some of the fats in the milk scatter and deflect light somewhat uniformly throughout the visual spectrum.
This, in turn, results in milk being fairly opaque and appearing white to our eyes.
And if you see a blue-ish tinge to the otherwise white milk
It's because it's a fat-free skimmed milk.
You see, without the fats, the smaller protein molecules in milk reflect more blue wavelengths of light, which is why skimmed milk can have a slightly blue-ish tinge.
Question
If you have to describe milk as though the person you are talking to has never tasted it before, how would you do it?
You can comment your answers below. :D