Optimization of garlic oil extraction via batch microwave- assisted hydrodistillation

The batch microwave-assisted hydrodistillation (MAHD) process has become a popular green extraction technique to extract essential oils from natural plants. The traditional hydrodistillation process is less efficient than the MAHD as the former often requires longer extraction period and higher energy consumption. This paper reports an optimization study of the batch MAHD process coupled with ethanol-water solvent in extracting garlic oil. A fundamental model of the batch MAHD process is used to simulate the extraction yield under various input conditions. The result of the model-based optimization is compared with the result from an experimental-based optimization. The objectives of the optimization are to maximize the extraction yield while simultaneously minimizing the extraction period and total energy consumption. This optimization results in the extraction efficiency and productivity equal to 90.44 μg/kJ and 3,254 μg/minute of garlic oil respectively.