Abstract:

Rice bran subjected to supercritical CO2 treatment for the removal of fat was extracted to obtain dietary fiber. Dietary fibers from treated bran and untreated rice bran were compared for the differences in their physical properties including expansibility, water-holding capacity, water-retention capacity and oil-retention capacity. The expansibility, water-holding capacity, water-retention capacity of the dietary fiber from treated rice bran with the same particle sizes all increased when compared with that from untreated rice bran, while the oil-retention capability displayed an opposite change. For both of the dietary fibers, the highest water-holding capacity and oil-retention capacity were both achieved at the particle size of 0.246 mm, and the highest expansibility and water-retention capacity at 0.900 mm and 0.175 mm, respectively, and the highest weighted value of the above 4 parameters at 0.246 mm. The highest weighted value of the above 4 parameters of the dietary fiber from treated rice bran was 27.75% higher than that of the dietary fiber from untreated rice bran. Supercritical CO2 treatment resulted in an increase in dietary fiber yield of 36.63%.

Key words: rice bran, dietary fiber, supercritical CO2, physical properties