Lipid removal enhances separation of oat grain cell wall material from starch and protein

Effects of lipid removal on the fine milling and air classification processing of oats were studied. Lipid removal by supercritical carbon dioxide (SC-CO2) extraction enabled concentration of the main components of oats – starch, protein, lipids and cell walls – into specific fractions. Using defatted oats as raw material, the highest β-glucan concentration of the cell wall-enriched fraction was 33.9% as compared to 17.1% without lipid removal. This was probably due to more efficient milling yielding smaller particles, and release of starchy material from cellular structures during milling of defatted oats, resulting in better classification. The removal of lipids also enabled separation of an oat protein concentrate with a protein concentration of 73.0% and a mass yield of 5.0%. A trial with 2310 kg of oat groats showed that the process based on defatting and dry fractionation was also industrially applicable.

► The lipids of oats were removed by supercritical carbon dioxide extraction.
► Defatting enabled concentration of starch, protein, lipids and cell walls into specific fractions.
► Highest β-glucan concentration of defatted, cell wall-enriched fraction was 33.9%.
► Highest protein concentration obtained from the endosperm fraction was 73.0%.
► The process was industrially applicable.