Abstract:
The study investigated the effect of addition of native and fermented rice bran on the
physicochemical, functional and nutritional properties of rice flour and bread. Response surface
methodology was used for the experimental design which generated a total of thirteen runs. Four
best runs were selected based on the optimization of the crude protein and fibre content, viz: runs
(1, 4, 8 and 10) which had rice, fermented rice bran and wheat flours in the ratios
60.00:24.20:15.80, 86.92:13.80:0.00, 60.00:10.00:30.00 and 69.29:21.89:10.23 respectively. The
proximate composition of the selected runs gave protein content (7.33-9.47%) and crude fibre
content (0.79-4.99%). The functional properties of the flours from the optimum runs were water
absorption capacity (77.72-84.95%), oil absorption capacity (110.73-127.81%), foaming capacity
(5.00-5.90%), swelling capacity (201.00-271.00 g/ml). The anti-nutritional factors of the flour
blends gave low value of anti-nutrients such as oxalate (0.270-1.305 mg/g), tannin (1.060-1.941
mg/g), alkaloid (6.813 -10.413 mg/g) and phytate (9.476-19.364 mg/g). Further analyses on the
mineral components of the flour blends, showed significant quantities of potassium (1183-4906
mg/kg), phosphorus (108.60-475.00 mg/kg), sodium (113.50-19.90mg/kg) and iron (19.00-32.00
mg/kg). More so, the antioxidant properties of the flours were Fe2+ chelation (0.270- 1.305%),
FRAP (3.261- 8.689 mg AAE/g), DPPH (69- 76%), ABTS (0.011 -0.023%), total phenol (2.310
-4.544%) for flour samples and the bread samples have higher values in both DPPH (47-81%)
and FRAP respectively (9.30- 13.93 mg AAE/g). The flours also showed soluble and insoluble
fibre in the range of (17.750 -36.630%) and (61.870- 82.150%) respectively. Bread was
produced from the composite flour and subjected to sensory evaluation on a nine point hedonic
scale with overall acceptability in the range of (5.80 -6.03), crumbiness (6.17 – 6.57) and
crustiness (6.30 -6.63). The study concluded that composite flour made from rice, fermented rice
bran and wheat flours could significantly increase the valorization potential of rice and rice bran.
