On Food and Cooking

endosperm, germ, and bran make this
separation possible: the first is easily
fragmented, and the others are oily and
leathery respectively. The germ and the bran
— which in practice include the aleurone
layer just underneath it — together account
for most of the fiber, oil, and B vitamins
contained in the whole grain, as well as some
25% of its protein. Yet these parts of the grain
are usually removed entirely or in part from
rice and barley grains, and from cornmeal and
wheat flours. Why this waste? Refined grains
are easier to cook and to chew, and more
attractively light in color. And in the case of
flours, the high lipid concentrations in the
germ and aleurone layer shorten the shelf life
of whole-grain flours substantially. The oils
are susceptible to oxidation and develop
rancid flavors (stale aroma, harsh taste) in a
matter of weeks. Today most refined cereals
in industrial countries are fortified with B
vitamins and iron in order to compensate for