ABSTRACT
Bioactive compounds are widely distributed in plant sources and are the most abundant secondary metabolites of the plants. Based on chemical characterization, they include: glycosides, flavonoids, tannins, terpenoids, lignans, alkaloids, peptides, and others. The extraction of bioactive molecules has drawn increasing attention due to their antioxidant and therapeutic potential through their interactions with vascular endothelial cells to prevent cardiovascular disorders and cancer. Although the development in chromatographic and spectrometric analytical techniques has significant contribution in the detection of bioactive components, the success depends on the method of extraction as two-third part of analytical work is required to get these components. In conventional extraction methods, several combinations of temperature, solvent, agitation speed, and extraction time have been optimized to get maximum yields, but these conventional proposals are creating burden on environment due to high temperatures for a long time and secondly, affect the 4heat-sensitive bioactive components. Alternatively, application of novel techniques like ultrasound, microwave, high pressure, pulsed electric field, supercritical fluid, and others is more welcoming due to less environmental burden in the form of lessened usage of organic solvents, low working temperatures, short duration, and improved quality and yield with high selectivity to compounds of interest. The efficiencies of both either conventional or novel extraction methods are typically based on the input parameters, complexity of plant source, structural conformation of bioactive components, and skill to up-scale them. This chapter aims to discuss basic mechanisms involved in the extraction of bioactive molecules from plant material through conventional as well as novel extraction techniques.
