Chapter 12 - Ultrasound and Microwave as Green Tools for Solid-Liquid Extraction

Abstract

Solid-liquid extraction is an important step to obtain bioactive compounds from a natural matrix such as microalgae, aromatic or medicinal herbs, and fruits and vegetables. For example, the microalgal cell wall disruption is an important and complex stage, and effective methods of disruption are fundamental to extract targeted molecules. Ultrasound and microwave are two extraction techniques considered as intensification techniques to reduce processing time, energy, and solvents. Indeed, compared with conventional methods, these techniques present the advantages of being efficient, fast, and industrially mature. Ultrasound and microwave have been involved in several studies to extract targeted compounds such as phenolics, carotenoids, and chlorophyll. This chapter will present ultrasound and microwave as suitable green extraction technologies for obtaining functional compounds from microalgae as an example of natural matrix.