LIEN HWA
From Wheat To Flour
Bran, the outside coating that holds the wheat berry together and protects it.
Germ, the embryo of a new wheat seedling were it to germinate.
Endosperm ("that which is within the seed"), the remaining part of the wheat berry that is the food or nutritive source for the growing wheat seedling.
While many espouse the use whole grains for their nutritional value, there are some benefits to flours that don't contain the germ or bran. The most obvious is that the gluten-producing protein are in the endosperm, not the germ or the bran. A bread dough made from flour ground form just the endosperm-white flour-will enjoy the greatest expansion and create the lightest loaf since there is nothing to interfere with the gluten. The bran, no matter how finely ground, has sharp edges that tend to shred the strands of gluten that have been developed in a dough. When the gluten matrix is torn, some of the carbon dioxide bubbles created by the yeast escape, resulting in a denser loaf. Second, the oil-rich germ, like any other vegetable oil, will eventually become rancid. Before the development of the refrigerator or freezer, storage of whole grains for any period of time was a real problem. Flour that doesn't contain the germ, if kept cool and dry and free of infestation, will keep almost indefinitely, with no loss in performance or nutritional value. All of these considerations made white flour very desirable.
Bran, the outside coating that holds the wheat berry together and protects it.
Germ, the embryo of a new wheat seedling were it to germinate.
Endosperm ("that which is within the seed"), the remaining part of the wheat berry that is the food or nutritive source for the growing wheat seedling.
While many espouse the use whole grains for their nutritional value, there are some benefits to flours that don't contain the germ or bran. The most obvious is that the gluten-producing protein are in the endosperm, not the germ or the bran. A bread dough made from flour ground form just the endosperm-white flour-will enjoy the greatest expansion and create the lightest loaf since there is nothing to interfere with the gluten. The bran, no matter how finely ground, has sharp edges that tend to shred the strands of gluten that have been developed in a dough. When the gluten matrix is torn, some of the carbon dioxide bubbles created by the yeast escape, resulting in a denser loaf. Second, the oil-rich germ, like any other vegetable oil, will eventually become rancid. Before the development of the refrigerator or freezer, storage of whole grains for any period of time was a real problem. Flour that doesn't contain the germ, if kept cool and dry and free of infestation, will keep almost indefinitely, with no loss in performance or nutritional value. All of these considerations made white flour very desirable.