Optimization of Microwave-Assisted Extraction of a Bioherbicide from Canavalia ensiformis Leaves

The objective of this study was to optimize the operational conditions of the Microwave-Assisted Extraction (MAE) of Canavalia ensiformis leaves by Response Surface Methodology (RSM), based on analysis of phenolic compounds obtained from the aqueous extracts. Optimal conditions for MAE were temperature of 100°C, extraction time of 10 min and ramp of temperature of 5 min, using approximately 2 g of dry plant material and 30 mL of water. The extracts obtained were determined by HPLC-UV. Among the phenolic compounds present in plant leaves, ferulic acid was selected as reference in all analyzes of the extracts. The results showed that the developed model was able to describe the effects and the relationship between them in the performance of the extraction, taking full advantage of all the limitations of the equipment.