Effect of extrusion pretreatment on extraction, quality and antioxidant capacity of oat (Avena Sativa L.) bran oil

Extrusion is an alternative pretreatment for oil extraction from cereal resource. The objective of this study was to assess the feasibility of extrusion pretreatment of oat bran for oil extraction. The effects of extrusion conditions including feed moisture content, screw speed and die temperature on the extraction, quality and antioxidant capacity of oat bran oil were investigated. The results showed that the extraction yield of oat bran oil varied from 3.93% to 8.43% under different extrusion conditions. A feed moisture content of 25% had an important effect on the extraction of oil from oat bran. Extrusion pretreatment could increase oil extraction efficiency by increasing expansion index and porosity of oat bran extrudates. Extrusion processing had no positive or adverse effect on the fatty acid compositions, and acid, peroxide and iodine values. Meanwhile, extrusion processing did not affect the phytochemical components and antioxidant capacity of oat bran oil. But refining process could result in decrease of phytochemical components and antioxidant capacity of oat bran oil. These results indicated that extrusion is a feasible and potential pretreatment procedure for oil extraction from oat bran.