Optimization of Ultrasonic- and Microwave-Assisted Extraction of Antibacterial Compounds from Amomum tsao-ko Fruit

摘要

The extraction of antibacterial compounds from Amomum Tsao-ko fruit was optimized for ultrasonic- and microwave-assisted methods. The antibacterial activity of the extracted compounds was determined based on the antibacterial diameter. To optimize the extraction procedure, the ethanol concentration, solvent-to-solid ratio, extraction temperature, and extraction time were evaluated using single factor experiments and the response surface methodology. A Box-Behnken design and analysis of variance were used to determine the optimal extraction conditions from the experimental data. The optimal parameters included an ethanol concentration of 65% (v/v), a solvent-to-solid ratio of 25 mL/g, an extraction temperature of 57.5 °C and an extraction time of 52.5 min. The extract obtained under optimized conditions had a maximum antibacterial diameter of 14.20 mm for Escherichia coli.