Effect of Germination on Functional Properties and Degree of Starch Gelatinization of Sorghum Flour

Sorghum grains were germinated for 24, 48 and 72 hours with a view to determining the effect of germination on some functional properties and degree of starch gelatinization of the flour. Flour from non-germinated grains served as control. In order to measure the effect of germination on degree of starch gelatinization, the flours were processed into cookies. Germination of sorghum grains for 48 hours and above significantly (p<0.05) decreased both loose and packed bulk densities from 0.59 g/ml and 0.77 g/ml to 0.56 g/ml and 0.70 g/ml respectively. The water absorption capacity of the sample germinated for 72 hours was 1.38 g/g which was significantly (p<0.05) higher than the other samples. The oil absorption capacity of the samples germinated for 48 and 72 hours (1.16 and 1.18 g/g respectively) were significantly (p<0.05) higher than those of the control sample and 24 hour germination (1.03 and 1.04g/g respectively). Germination also significantly (p<0.05) increased the swelling power (22-23.2 ml/g), foaming capacity (14-16.2%) and emulsion capacity (58.6-65.5%). The degree of starch gelatinization increased with increasing germination time but decreased with increasing temperature. Generally, germination had a beneficial effect on the functional properties measured. Flour obtained from sorghum grains germinated for 72 hours had the best results.