Adding beta-glucans, arabinoxylans improves cereal health profiles.

You can improve the health profile of many cereal products by adding beta-glucans and increasing the content of soluble arabinoxylans. These soluble fibers lower blood cholesterol levels, a risk factor for coronary heart disease. They also reduce the postprandial glycemic response--blood sugar level. This capability is potentially beneficial in controlling the adverse effects of diabetes.

Beta-glucans are present in many cereals. They are found in high levels in oat and barley. Arabinoxylans and other xylans are also found in a number of plant tissues, for instance in wheat, where they improve the baking strength of the flour.

In Europe, researchers have been focusing on new hull-less and waxy barley varieties that have high beta-glucan content. They also have examined the milling of these grains in order to optimize beta-glucan-rich fractions that can be used to supplement wheat flour. Their research also has considered other health-related or functional components in the barley fractions: arabinoxylan, tocopherols, tocotrienols, flavonoids, beta-glucanases, endoxylanases and endoxylanase inhibitors.

The scientists have optimized the barley fractions. The investigators evaluated the baking characteristics of mixed wheat flour and barley fractions. There was an apparent weakening of the mixes compared with basic wheat flour. The lower baking strength of the mixes is probably influenced by xylanases and their inhibitors. For that reason, scientists began a study of the xylanases and the xylanase inhibitors. Bread-making experiments showed that xylananses were able to reduce the negative effects of adding hull-less barley to flour.

Such a product will be useful in bread-making and other food applications in which increased soluble fiber levels are desired. These will have a significant added value in terms of health-promoting effects that can be achieved by increasing the levels of both soluble beta-D-glucan and arabinoxylan of high molecular weight.

Further information. Jan Delcour, Laboratory of Food Chemistry, Catholic University of Leuven, Kasteelpark Arenberg 20, 3001 Leuven, Heverlee, Belgium; phone: +32 16 321581; fax: + 32 16 321997; email: Jan.Delcour@biw.kuleuven.be.