butterscotch.
The Development of Off-Flavors The flavor
of good fresh milk can deteriorate in several
different ways. Simple contact with oxygen or
exposure to strong light will cause the
oxidation of phospholipids in the globule
membrane and a chain of reactions that slowly
generate stale cardboard, metallic, fishy,
paint-like aromas. If milk is kept long enough
to sour, it also typically develops fruity,
vinegary, malty, and more unpleasant notes.
Exposure to sunlight or fluorescent lights
also generates a distinctive cabbage-like,
burnt odor, which appears to result from a
reaction between the vitamin riboflavin and
the sulfur-containing amino acid methionine.
Clear glass and plastic containers and
supermarket lighting cause this problem;
opaque cartons prevent it.
Unfermented
Dairy Products