Steenbock and Boutwell (10) observed that yellow maize is far superior to white or red varieties as a source of fat-soluble A. They believed at one time that the fat-soluble A is in general associated with the yellow pigment of plants. This view has been in great measure discarded.

Maize which is used as human food is now freed from its germ and its bran layer in a manner analogous to wheat, and also for the purpose of improving its appearance and more especially its keeping qualities. Maize germ, like wheat germ, is rich in oil and this tends to become rancid when the kernel is ground and exposed to the air. Meal which contains the germ is more liable to harbor insects when kept over a period of warm weather, than is ordinary corn meal. Both white and yellow grain is used for making meal for human consumption. The former is in greatest general favor with the public because it has been educated to a liking for white flour and white rice. Corn oil is now marketed as a salad oil.