Baking healthy bread with barley
Using just a small amount of barley fibre in bread can improve the health benefits of a loaf of wheat bread. Researchers at the Canadian Grain Commission have made fibre-rich fractions by milling hulless barley. They have found that adding barley fibre fractions to wheat flour makes bread that looks and tastes good. It also has the added benefit of high levels of beta-glucans. This new use for barley is good news for consumers and it opens new markets for barley producers.
Beta-glucans, dietary fibre and your health
Barley grain is an excellent source of soluble and insoluble dietary fibre. The most plentiful fibre constituents in barley are compounds called beta-glucans. Studies have shown that beta-glucans lower plasma cholesterol, improve lipid metabolism and reduce the glycaemic index. The United States Food and Drug Administration (FDA) allows whole grain barley and products that contain barley to carry a claim stating these products reduce the risk of coronary heart disease.
Canadian barley is known world-wide for its excellent malting and brewing qualities. It is also used in animal feed. However, hulless varieties with waxy starch have been developed for human food use. These Canadian varieties include CDC Alamo, CDC Fibar and CDC Rattan. They contain higher amounts of beta-glucans than traditional malting barley varieties.
Milling for fibre-rich barley fractions
The Canadian Grain Commission’s researchers developed a simple roller milling flow that obtains high-fibre fractions containing beta-glucans from whole barley grain. Roller milling is traditionally used to mill wheat into flour. Researchers found that if they added a few refinement steps to the original milling process, they were able to increase the concentration of total dietary fibre and of beta-glucans. Extra refining also increased the brightness of the barley fibre fractions which resulted in a creamy-coloured bread crumb.
You can buy purified beta-glucan isolates, but the beta-glucans found in these products are usually obtained through complex chemical processes. Roller milling is a dry, physical process that does not require any solvents. Fibre fractions obtained through milling have more nutritional value than beta-glucan isolates because these fibre fractions also contain other forms of dietary fibre, minerals, phenolics and vitamins.
Percentage of barley fibre fractions in wheat bread
Barley fibre fractions have an advantage over barley flour because fibre fractions have several times more beta-glucans than barley flour. To get the FDA-recommended dosage of 0.75 grams of beta-glucan per 2-slice serving, researchers found that they only need to replace 10% of wheat flour with hulless barley fibre fractions. If they use the more refined fibre fractions, the researchers only need to replace 6% of wheat flour. The result is a loaf of bread that contains the recommended level of beta-glucans and that is similar in taste and appearance to regular white bread. To get the same health benefits from barley flour a large amount of wheat flour will have to be replaced and the bread recipe will have to be modified to avoid significant changes in the taste, appearance and texture of the bread.