Oat and Rye β-Glucan: Properties and Function

Over the years, the beta-glucan of oats and barley has been the subject of study either because of the importance of the cholesterol-lowering potential to health claims (FDA 1997, 2005) or, in the case of barley, because of the role of beta-glucan and beta-glucan-rich endosperm cell walls in malting and brewing. beta-Glucan is also present in rye and in much lesser amounts in wheat. The most striking difference in these latter two sources is the difficulty in extractability; alkali rather than water is required for significant release from the cell walls. This review will discuss physicochemical properties of oat and rye beta-glucan and, where information allows, relate these to physiological effects. Viscosity, or more generally rheology, plays a central role in discussions of cereal beta-glucan functionality and physiological effects and will be the focus of this review.