Hydrolytic Stability and Changes in E Vitamers and Oryzanol of Extruded Rice Bran During Storage

Abstract
Rice bran was extruded at 110, 120, 130, and 140°C with post extrusion holding times of 0, 3, and 6 min and stored at ambient temperatures for 1 yr. Holding time had no effect (p>0.05) on hydrolytic stability whereas 110°C was slightly less effective in maintaining hydrolytic stability. Increased holding times reduced (p<0.05) total vitamin E content. Oryzanol concentration was lower (p<0.05) only after 6 min holding time. Oryzanol was relatively more stable to extrusion temperatures than vitamin E. The highest retentions of total vitamin E and oryzanol were found in raw rice bran during storage. Increased extrusion temperatures reduced the retention of vitamin E and oryzanol during storage.