Effect of Germination Period on Some Functional and Engineering Properties of Sorghum Flour

Abstract

Sorghum (red and white) were germinated for 24, 48, 72, and 96 h to determine the effect of germination on some functional and engineering properties of sorghum flour. The bulk density results for the red and white germinated sorghum are 0.620-0.673 g/cm3 and 0.477-0.620 g/cm3, respectively. Water absorption capacity values for the two samples are 116.630-125.970% and 81.643-98.293% while the oil absorption capacity ranged from 62.917 to 85.750% and 44.933 to 61.980%, respectively for the two samples. The dispersibility test for the two samples gave 85.67-87.33% and 83.00-84.67%. The swelling power at 55 °C are 2.54-2.67 and 2.70-3.26, at 75 °C, 3.62-4.68 and 3.85-4.56, and at 90 °C, 2.98-4.79 and 6.29-7.23, respectively for the two samples. For the engineering properties, the specific heat capacity ranged from 0.14 to 0.45 kJ/kg K and 0.12 to 0.14 kJ/kg K, thermal conductivity, from 0.55 to 1.67 W/mK and 1.01 to 1.24 W/mK and thermal diffusivity from 0.13 to 0.82 m2/s and 0.11 to 0.12 m2/s, respectively for red and white germinated sorghum flours. It can be concluded from this study that increased the values of bulk density, WAC, OAC, and dispersibility test of the two samples with the increase in germination period with the optimum germination period of 72 h. Engineering properties results indicated that germination had a beneficial effect on the thermal conductivity of the germinated red sorghum and the thermal conductivity and specific heat capacity of the white germinated sorghum with 96 h having the best result for both samples.