Study on the microwave extraction process and product distribution of essential oils from citrus peel

Citrus peel wastes containing a series of very beneficial active compounds are produced in large quantities around the world every year, which are usually extracted by traditional methods, requiring high energy costs, long extraction times and additional reagents. Based on the unique heating characteristics of microwave heating, this paper uses microwave heating to extract the essential oils of citrus peel. Exploring the content change rule and the composition distribution situation of citrus peel product with different reaction time and microwave power, and comparing the microwave extraction and conventional extraction methods of citrus peel essential oils, infer the mechanism of microwave extraction. Considering the efficiency and energy consumption, optimum microwave power and time were selected as 450 W and 10 min. At microwave power of 450 W, 29.22% liquid product was obtained with 37.82% limonene yield in the liquid. The limonene yield per unit energy consumption in case of microwave heating was found to be 18.6 times that of traditional heating, and the extraction mechanism based on microwave heating effect and pumping effect was proposed.