Investigation of various factors for the extraction of peppermint (Mentha piperita L.) leaves

Ingredients from peppermint leaves are widely used in the food industry as food additives and natural flavours. The traditional way to produce mint extracts is via steam distillation or solvent extraction, both long and energy consuming processes. This paper investigated various extraction methods, namely room temperature extraction, reflux temperature extraction, ultrasonic assisted room temperature extraction and microwave-assisted extraction. Extraction of peppermint leaves was studied for extraction times of 5, 10, 30 and 60 min, varying the sample-to-solvent ratio, along with the study of extraction yields for three mint compounds, menthone, menthol and menthofuran. The use of microwave-assisted solvent extraction allows the reduction of process time, the reduction of solvent use, while increasing extraction yields.