the seed”) is often the only part of the grain
consumed. It consists of storage cells that
contain starch granules embedded in a matrix
of protein. This matrix is made up of normal
cell proteins and membrane materials, and
sometimes of spherical bodies of special
storage proteins which, squeezed together as
the starch granules grow, lose their individual
identity and form a monolithic mass. There’s
generally more starch and less protein per cell
near the center of the grain than there is near
the surface. This gradient means that the more
grains are refined by milling and polishing,
the less nutritious they get.
Milling and Refining
People began treating the grains to remove
their tough protective layers in prehistoric
times. Milling breaks the grains into pieces,
and refining sifts away the bran and germ. The
very different mechanical properties of