The majority of food uses, however, require more processing. First, the grain is cleaned and conditioned by adding water. This causes the kernel to break up properly when it is milled. During the milling process, the grain is cracked, then flattened by rollers. This process continues and particles are sifted by size until about 70 percent of the grain has been powdered into flour.
White flour contains only the endosperm of the kernel and stores longer without spoiling.
Whole-wheat flour contains more parts of the kernel, the bran and the germ, which makes it healthier to eat but more susceptible to spoilage. Since wheat is the only grain with enough gluten to make a raised or leavened loaf of bread, it was quickly favored over other grains grown at the time, such as oats, millet, rice, and barley. Specimens were illuminated through Nikon dichromatic filter blocks containing interference filters and a dichroic mirror and imaged with standard epi-fluorescence techniques. All Rights Reserved . No images, graphics, scripts, or applets may be reproduced or used in any manner without permission from the copyright holders.