On Food and Cooking

triglyceride, which is formed from one
molecule of glycerol and three fatty acids. The
acidic heads of the fatty acids are capped and
neutralized by the glycerol, so the triglyceride
as a whole no longer has a polar, water-
compatible end. The fatty-acid chains can
rotate around the glycerol head to form chair-
like arrangements (bottom).
Fat Saturation and Consistency Saturation
matters in the behavior of fats because double
bonds significantly alter the geometry and the
regularity of the fatty-acid chain, and so its
chemical and physical properties. A saturated
fatty acid is very regular and can stretch out
completely straight. But because a double
bond between carbon atoms distorts the usual
bonding angles, it has the effect of adding a
kink to the chain. Two or more kinks can
make it curl.
A group of identical and regular molecules
fits more neatly and closely together than
different and irregular molecules. Fats