Study on Functional Properties of Physically Modified Dietary Fibres Derived from Defatted Rice Bran

In this study, we investigated the predictive indices for hypoglycemic effect of physically modified fibers. Micronization, ultrasonic, microwave and extrusion cooking treatments were applied to defatted rice bran dietary fibers to get modified defatted rice bran dietary fiber. The effects of physical treatments, pH and time of digestion, on the water binding Capacity (WBC), Swelling Capacity (SWC), Cation exchange Capacity (CEC) and Glucose retardation capacity (GDRI) were studied. All modified fibers exhibited significance (p<=0.05) difference in terms of their hydration capacity at pH 8.7 with extruded fibers showing the highest values for WBC and SWC (4.68g/g and 3.66 ml/g respectively), while micronized fiber had the lowest value of CEC at pH 1.8 (0.15 meq/g). Extruded fiber showed higher GDRI (40.73%), thus higher glucose adsorption capacity (4161µmol/g). It displayed greatest retardation effect against the movement of glucose across the dialysis bag for 9 h compared to other treatments. The study showed that physically modified defatted rice bran dietary fibers have reduction effect on glucose breakdown rate and adsorption and thus can avoid increase in postprandial blood glucose level Therefore, these physically modified fibres showed important improved physiological effects (hypoglycemic effect) and can be incorporated in foods to enhance health benefits.