Microwave reflux extraction—An alternative approach for phenolic-rich oleoresins extraction from functional plants

There is an undeniable evidence on the biopharmaceutical applications of phenolic extracts from functional plants in the treatment of many life-threatening diseases. A comparative review on the microwave and conventional extraction techniques were adequately outlined with their inherent drawbacks. The mechanism of microwave-assisted extraction was carefully discussed coupled with their operating factors. The important highlight in this overview involves the presentation of a theoretical basis for the energy audit in the microwave system. This involves an estimation of absorbed energy by the solvent-sample system during the extraction process. Moreover, the application of orthogonal optimization tools in the biochemical intensification of the extraction process was succinctly discussed. This review, therefore, elucidated the efficacy of microwave-assisted techniques in synthesizing bioactive phenolic constituents from functional plants which serve both medicinal and nutritional purposes.