From Field to Shelf: How Microwave-Assisted Extraction Techniques Foster an Integrated Green Approach

Microwave-assisted extraction of organic compounds from vegetal matrixes is a relatively
young ield of research. The exceptional results achievable at the laboratory scale by microwave-assisted extraction, like shorter extraction times, lower average temperatures, reduction of organic solvents use, higher yields and selectivity, as well as energy and cost saving,
are not always accompanied by a successful scale up. Nevertheless, microwave-assisted
techniques of extraction have been multiplying during last decades. In this framework,
a deeper knowledge of microwave applicator design criteria is mandatory. This chapter
starts from the basis of microwave heating and the relevant material properties involved in
a successful microwave-assisted extraction application, to continue with a short overview
on how such properties can be measured and used to optimize the experimental setup or
a possible scale up of the process under investigation. A comprehensive review of recent
applications of microwave-assisted extraction, applied to vegetal matrixes, is presented
next. The chapter ends reviewing duplex treatments of vegetal matrixes for extraction
purposes, where microwave heating is coupled to other techniques, like ultrasounds, and
indicating new paths, where the recent advent of new microwave solid-state generators
has led to beter process control and higher yields and energy efficiency.