casein micelles a haircut (p. 57). It clips off
just the part of the capping-casein that extends
into the surrounding liquid and shields the
micelles from each other. Shorn of their hairy
layer, the micelles all clump together —
without the milk being noticeably sour.
The Whey Proteins Subtract the four caseins
from the milk proteins, and the remainder,
numbering in the dozens, are the whey
proteins. Where the caseins are mainly
nutritive, supplying amino acids and calcium
for the calf, the whey proteins include
defensive proteins, molecules that bind to and
transport other nutrients, and enzymes. The
most abundant one by far is lactoglobulin,
whose biological function remains a mystery.
It’s a highly structured protein that is readily
denatured by cooking. It unfolds at
172ºF/78ºC, when its sulfur atoms are exposed
to the surrounding liquid and react with
hydrogen ions to form hydrogen sulfide gas,