Combination of defatting and dry fractionation technologies to produce oat ingredients with high beta-glucan concentration

This paper describes a novel and feasible fractionation method to increase the amount of β-glucan in oat bran. Special attention has also been paid to the recovery of other oat fractions: protein, starch and lipids. We evaluated how the defatting of oat by supercritical carbon dioxide (SC-CO2) affects the behaviour of oats in different dry fractionation processes by conducting both pilot and industrial scale defatting with subsequent milling and air classification trials. In addition, we followed the distribution of different grain components in each fraction. Lipid removal enabled an effective separation of bran, starch and protein particles, and the β-glucan concentration in the bran fraction could be increased to 35%. The product had low lipid content, and thus a prolonged shelf life. The fractionation process was optimised in terms of the yield of bran fraction and its β-glucan concentration. The cost-effective production of high purity β-glucan concentrates, obtained according to this study, would enable feasible manufacture of new types of oat based functional food products.