Extraction of natural food ingredients by modern techniques

Conventional techniques commonly used to extract bioactive compounds are maceration, hydrodistillation, and Soxhlet. These techniques have disadvantages such as low extraction yields, long processing times, and utilization of hazardous solvents. In addition, high temperatures may result in the degradation of phytochemicals. This chapter focuses on modern extraction methods such as ultrasound-assisted extraction, microwave-assisted extraction, pressurized fluid extraction, pulsed electric field extraction, and high-pressure extraction. The emerging techniques may be efficient pretreatment or extraction methodologies with low solvent and energy consumption and short extraction times. They have been used for the extraction of polysaccharides and bioactive compounds from plant sources, and the extracts showed higher yields and antioxidant activities than those extracted using conventional techniques. Better results can be achieved after optimizing the process parameters, such as extraction cycles, processing time and temperature, solvent composition and flow rate, solvent-sample ratio, and pressure, among others. The importance of the process variables is dependent on the applied technology.