A soluble dietary fiber, $eta$-glucan, contained in oat and barley has nutritional benefits such as hypocholesterolemic effects and influences blood glucose regulation. The contents of $eta$-glucan in both cereals range from 3 to 7% with the exception of a certain barley genotype which contains up to 16% $eta$-glucan. $eta$-Glucan is distributed mainly in the cell walls of endosperm and the distal (bran) portion of kernel. Various procedures have been developed for increasing the extraction yield of $eta$-glucan. Oat gum prepared with weak alkali extractionand alcohol proecipitation following protein removal usually contains 80% $eta$-glucan.The most commonly used method for $eta$-glucan quantitiation is an enzymatic procedure combining lichenase plus $eta$-glucosidase followed by measuring the amount of glucos released by glucose oxidase-peroxidase treatment. The increase in foam-and emulsion-stabilizing capacity of $eta$-glucan is due to the increase in viscosity of the aqueous phase. Therefore, $eta$-glucan shows great potentials as a thickener and a stabilizer.