Barley as an ingredient for functional food products

Compared to other cereals, the food use of barley is limited. However, barley is a highly potential raw material for health promoting dietary fiber, resistant starch, minerals and vitamins. Of the major cereal crops, barley and oats have the highest contents of beta-glucan, a soluble dietary fiber component in cereal cell walls. Beta-glucan in barley is distributed throughout the kernel, making traditional aleurone bran separation processes inefficient in concentrating barley beta-glucan. However, the separation can be intensified by raw material selection. Beta-glucan incorporation into beverage applications is challenging due to the high viscosity and structural instability. By applying methods that reduce beta-glucan molecular weight and inactivate endogenous glucanolytic activities, the suitability of beta-glucan in beverages can be enhanced. From the literature, several methods are available for reductions of molecular weight of beta-glucan. These include enzymatic hydrolysis, mechanical shear stress and acid catalyzed hydrolysis. A new protocol based on acid catalyzed hydrolysis produces beta-glucan with narrow molecular weight distribution and total inactivation of endogenous activities. This material can be incorporated in beverages to provide around 10 g of beta-glucan in one serving. The beta-glucan in this type of product is stabile over wide range of pH values and temperatures. Both barley and malt are natural ingredients that could be used to a greater extent in non-alcoholic beverages, combined with, for example berries and fruit juices. Drinks are easy to carry and consume, which make them convenient, daily supplies of dietary fiber for the modern consumer.