Functional Properties of Flours from Five Nigerian Rice Cultivars

Abstract

In this study, the functional properties of five Nigerian rice cultivars (Bisalachi, Ebagichi, Lamiyatu, Majalisa and Walue) were determined. Functional properties such as hydration, pasting and thermal parameters, and vibrational spectroscopy of the flours were determined using standard methods. Bulk density, water binding capacity, water holding capacity, water absorption index, water solubility index, oil absorption capacity and swelling power ranged from 0.32 to 0.41 g/cm3, 1.21 to 1.40 g/g, 1.33 to 1.92 g/g, 5.81 to 7.53 g/g, 1.49 to 1.74 g/g, 1.26 to 1.35 g/g, and 10.35 g/g to 12.80 g/g, respectively. Peak viscosity, trough viscosity,  breakdown viscosity, final viscosity, pasting temperature and peak time ranged from 158.04 to 187.30 RVU, 107.59 to 124.76 RVU, 50.45 to 62.54 RVU, 222.86 to
275.27 RVU, 115.27 to 151.89 RVU, 87.65 to 88.53 oC and 5.29 to 5.96 min, respectively. Onset, peak and conclusion temperatures, and enthalpy of  gelatinization ranged from 65.02 to 68.41 oC, 68.73 to 72.05 oC, 74.59 to 79.26 oC, and 11.62 to 14.88 J/g, respectively. Raman spectroscopy revealed that the bands in the spectra of the rice flours originated mainly from the vibrational modes of amylose and amylopectin. The results obtained are useful in determining the
application of the rice flours in food systems.

Keywords: Rice cultivars, flour, functional properties.