Extraction and isolation of plant bioactives

Natural bioactive compounds derived from plant materials play an important role in human health. It is desirable to find the most suitable methods for extracting and isolating those compounds from plant matrices. Techniques for extraction and isolation of bioactive compounds have been developed over the years. This chapter presents a general overview of the techniques involved in extraction and isolation of bioactive compounds from plants. Particularly, traditional extraction methods (steam distillation and solid liquid extraction), novel extraction techniques (microwave assisted extraction, ultrasound assisted extraction, supercritical fluid extraction, and pressurised fluid extraction) and isolation techniques (ion-exchange and high performance liquid chromatography) are reviewed. Comparisons of different extraction techniques, various applications and recommendations with specific examples for each technique are also discussed. Furthermore, the different evaluation techniques in vitro and in vivo for bioactivities and antioxidant activities of crude extracts or isolated/purified compounds are also presented.