Studies on Kinetics and Optimum Agitation of Phenolic Compound Extraction from Intact Red Sorghum

Quantitative analysis on the phenolic extraction from red sorghum grain for production antioxidant material in agitated vessel has been studied. The process is imagined to be controlled by the mass transfer of the functional compounds from surface of material to the bulk of solvent. Concentrations of the compound in extract are affected by agitation speed and extraction time. The purposes of this research are to evaluate the kinetics and to determine the optimum values of agitation speed and extraction time to raise the maximum performance of phenolic extraction from whole sorghum grains. The kinetic studies evaluated the accuracies of the second order kinetics model and the mechanistic model in predicting the process. The optimization was examined using two level factorial design of Response Surface Methodology based on data observed in the phenolic extraction using distilled water as solvent at 60 °C of temperature; 10:1 of sorghum-solvent mass ratio; 300, 400 and 500 rpm of agitation speed and 90, 120, 150 min of extractions time. In this case, the mechanistic model shows higher accuracy than the second order kinetics. The concentration of phenolic compound in the extract was predicted to be maximum at 407.1 rotations per minute (rpm) and 120.9 min of extraction time. The values of determination coefficient (R2) was 94.79. For the purpose of generalization, the kinetic model is quantitatively describe the proposed extraction process. © 2020, Springer Nature Singapore Pte Ltd.