EFFECT OF PASTING AND THERMAL PROPERTIES OF FLOURS AND STARCHES FROM ONE INDIGENOUS AND THREE IMPROVED LOCAL WHITE RICE

This study evaluated the pasting and thermal properties of flours and starches produced from four different rice varieties, including one indigenous and three improved local white rice varieties (Faro 44, 52, 61, and kwandala). The four samples (local rice varieties) were purchased from the National Rice Research Institute Badeggi, Niger, and were further processed into flours and starches. Thermal and pasting properties of the flours and starches were determined. The results obtained for the thermal properties of the rice starch showed that the onset gelatinization of the rice starches To (oC) ranged from 63.45°C to 78.31 °C, the peak of gelatinization Tp was 66.77°C to 80.01 °C, and the gelatinization conclusion Tc ranged from 72.01°C to 86.29 °C. The gelatinization enthalpy, ∆HG ranged from 1.30°C to 2.48°C. J/g and the melting range (Tc-To) 5.42 - 15.08°C in all four samples. The results of the pasting properties of the improved rice flours showed that the peak viscosity (PV cp) ranged from 2241.33 to 3312.45 and the trough viscosity (TV cp) ranged from 2007.67 to 2903.07. Breakdown (BD cp) 233.66 – 834.38, Final viscosity (FV cp): 4805.00–5678.00; setback (SBV cp): 2155.00–3142.41; peak time (PT): 5.96–6.11; and pasting temperature (Peak temp): 79.94–82.13. The results of the pasting properties of rice starch showed that the peak viscosity (PV cp) ranged from 4869.67 to 5439.33 and the trough viscosity (TV cp) ranged from 2328.67 to 3902.38. Breakdown (BDV cp) 1536.95 - 3014, Final viscosity (FV cp) 4356.00 - 6426.00, setback (SBV cp) 3089.33 - 3413.33, peak time PT (min) 4.28 - 5.27 ad the pasting temperature (Peak temp): 62.02–70.37. The properties of flours and starches from the indigenous and improved Nigerian rice cultivars should have desirable quality properties relevant for the postharvest value addition chain