What are Whole Grains?
Whole grains are cereal grains which contain the intact, ground, cracked or flaked kernel or seed of the grain as well as the endosperm, germ and bran.1 The American Association of Cereal Chemists International (AACCI) defines whole grains as "The intact, ground, cracked or flaked caryopsis, whose principal anatomical components – the starchy endosperm, germ and bran – are present in the same relative proportions as they exist in the intact caryopsis.”
Whole grains are an ingredient found in many products, including but not limited to:2
- Cereals/granola bars
Whole grains became a part of the human diet approximately 10,000 years ago, with the emergence of agriculture. For the past 3,000 to 4,000 years, a majority of the world’s population has consumed whole grains as a significant portion of their diet.
In the United States and Canada, wheat, oats, barley and rye were harvested as staple foods as early as the 1700’s. It wasn’t until the invention of the roller mill in the late 1800’s that it was efficient to separate the bran and germ from the endosperm; increased use of the roller mill led to an increase in demand for refined grain products and, consequently, a whittling of the demand and consumption of whole grain.3
Whole grains are rich in vitamins, minerals and dietary fiber.4 They provide a good source of phytochemicals and micronutrients, B vitamins, magnesium and selenium.5
Cereal grain kernels are composed of three main parts: the endosperm, bran and germ. Most cereal products – such as white bread or pasta – are made with kernels or flour that have had the bran and germ removed. The bran and germ are the highest fiber parts of the kernel.6 In order to be considered a whole grain, the bran and germ must be present in addition to the endosperm. In the production of whole grain flours of wheat, rye, barley, oat and maize, the kernels are broken, separated into milling streams containing endosperm rich white flour, germ and bran fractions and then combined in fixed ratios.
Whole grains are composed of bran, constituting 3 – 30% of the grains total weight; germ, constituting 4 – 17% of the grains total weight; endosperm, constituting...