What is the primary component of a grain that remains after refinement?

The primary component of a grain that remains after refinement is the endosperm. During the refinement process, grains are often milled to remove the bran and germ, which contain a significant amount of nutrients, fiber, and healthy fats. This process leaves primarily the endosperm.

The endosperm is the part of the grain that serves as a food source for the developing plant embryo and is rich in carbohydrates, primarily in the form of starch. Although the refined product might have a longer shelf life and a finer texture, it is in this state that many of the health benefits associated with whole grains are lost, including vitamins, minerals, and dietary fiber typically found in the bran and germ.

Bran and germ are removed during the refinement process, while starch is one of the main constituents of the endosperm, not a separate entity that remains after refinement. This distinction underscores the importance of understanding the composition of grains and the nutritional implications of consuming refined versus whole grains.