Evaluation of the Nutritional, Antioxidant and Physiochemical Properties of Rice Flour Fortified with the Nigeria Native "IGBEMO" Rice Bran Flour

Abstract

The study evaluate the physicochemical, functional and nutritional properties of rice flour fortified with Nigeria native rice bran flour. Response surface methodology was used and a total of thirteen runs was generated. The four best runs were selected from the thirteen based on the composition of their crude protein and fibre content viz: run (1, 4, 8 and 10). The proximate composition of the selected runs in protein (7.33-9.47%) and crude fibre (0.79-4.99%) respectively. The functional properties of the flours were WAC (77.72-84.95%), OAC (110.73-127.81%), foaming capacity (5.00-5.90%), swelling capacity (201.00-271.00 g/ml) has the best result obtained in run 8 respectively. The anti-nutritional factor of the flours were 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 high amount in potassium, phosphorus, sodium, iron and also appreciable amount of both zinc and copper. More so, the antioxidant properties of the flour samples were Fe2+ chelation (0.270-1.305%), FRAP (3.261-8.689 mg AAE/g), DPPH (69-76%), ABTS (0.011-0.023%), total flavonoid (0.009-0.050%) and total phenol (2.310-4.544%). The flours also showed high amount of insoluble fibres against soluble fibres. Hence, the flour blends could serve as a wheat flour substitute. Bread was produced from the composite flour blends 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).