Free fatty acids in rice bran during its storage after a treatment by twin-screw extrusion to prevent possible rapid hydrolytic rancidity of lipids

摘要

This research studied the prevention of hydrolytic rancidity during the storage of rice bran stabilized by an extrusion process.A double screw extruder was used, set at 130° C in the barrel and a rotational speed of the screws programmed at 200 RPM.The moisture content of the bran was adjusted at 20%.The treated bran was stored, using two packing methods (with and without vacuum), at two ambient conditions (18° C – 70 % RH and 30° C - 78% RH) for a period of 8 weeks.The content of free fatty acids (FFA) in the rice bran was observed during the storage time period.The extruded treated rice bran stored at 18° C - 70% RH resulted in lower values of FFA in comparison with the values in the bran kept at 30° C - 78% RH.Vacuum packaging showed a significant disadvantage as compared to packaging without vacuum.