Oat beta glucans
Oat bran is produced by removing the starchy content of the grain. It is rich in dietary fibers, especially in soluble fibers, present in the inner periphery of the kernel. Oats contain more soluble fibers than any other grain, with results including slower digestion and an extended sensation of fullness.
Oat is a rich source of the water-soluble fiber (1,3/1,4) β-glucan, and its effects on health have been extensively studied over the last 30 years. Oat β-glucans can be highly concentrated in different types of oat brans. The beta glucan content varies, from 3-5% depending on variety when it grows in the field. Rolled oat/oat flakes are about 4% and also wholemeal oat flour is about 4%. With Swedish Oat Fiber’s specially developed fractionating process, we can produce concentrations of beta glucans from 6% up to 32%.
Beta-D-glucans, usually referred to as beta glucans, comprise a class of indigestible polysaccharides widely found in nature in sources such as grains, barley, yeast, bacteria, algae and mushrooms. In oats, they are concentrated in the bran, more precisely in the aleurone and sub-aleurone layer (see picture above).
Oat beta glucan is a natural soluble fiber. It is a viscous polysaccharide made up of units of the monosaccharide D-glucose. Oat beta glucan is composed of mixed-linkage polysaccharides. This means the bonds between the D-glucose units are either beta-(1→3) linkages or beta-(1→4) linkages. This type of beta-glucan is also referred to as a mixed-linkage (1→3), (1→4)-beta-D-glucan. The (1→3)-linkages break up the uniform structure of the beta-D-glucan molecule and make it soluble and flexible. In comparison, the indigestible polysaccharide cellulose is also a beta glucan, but is not soluble. The reason it is insoluble is because cellulose consists only of (1→4)-beta-D-linkages.
Oat beta glucans are large molecules. Originally in the oat kernel, it is composed of up to 200,000 glucose units, which gives molecular weights in the range of 1500-3000 kDa. It is this native structure that the production process at Swedish Oat Fiber preserves, not destructing the molecular weight during fractionating into the oat brans with high amount of beta glucans. For more details, see the separate section about molecular weight.
Oats are generally considered more healthy and nutritious than the other main cereals. They are well-known for their benefits for digestion and have been eaten during hundreds of years by both animals and humans. Today many health-oriented people have their oat porridge every morning as their breakfast.
One of the more clinical breakthroughs was the discovery of oat beta glucan's cholesterol-lowering properties, especially for the metabolic syndrome. In recent years, clinical studies have proven the health benefits heart diseases by maintaining/lowering cholesterol, decreasing blood sugar response after eating and also improving gut health.
The power of beta glucan - fact sheet from Heart UK