Optimization of Agitation and Kinetic Studies on Proanthocyanidin Compound Extraction from Red Sorghum Grains in Agitated Vessel

Proanthocyanidin extraction for antioxidant material from intact red sorghum grains in agitated vessel had been investigated. The optimization and the appropriate kinetic evaluation were useful to conduct the engineering design of the developed process. Concentrations of the proanthocyanidin compounds in the aqueous extract were affected by the agitation speed and extraction time. The objectives of this research were to determine the optimum values of agitation speed and time for getting maximum extraction performance and to develop the appropriate kinetic model for illustrating the extraction phenomena. This research also evaluated the characteristics of the obtained extract. The optimum conditions of extraction were determined using Response Surface Methodology. The concentration of proanthocyanidin compound in the extract was predicted to be maximum at 405.05 rotations per minute (rpm) of agitation speed and 133.03 minutes of extraction time. The values of R-2 of the regression equations were 99.45%. In the kinetic modeling, the mechanistic model turns to be much more accurate than the second order kinetic. The extract from the optimum process had 0.837 mg/ml of proanthocyanidin concentration and was proven to be effective in scavenging 64.02% of free radicals in the 100 mu M DPPH in 30 minutes.