Novel methods for the extraction of antioxidant bioactive compounds from natural resources

Replacing conventional technologies by non-conventional ones, for the extraction of valuable compounds from vegetal resources , represents numerous advantages including on the one hand the reduction of the processing time, the consumed energy, and the uses of harmful and expensive solvents, and on the other hand, the increase of the extraction yields, in full correspondence with green extraction concept. Furthermore, some non-conventional technologies are able to extract selectively the intracellular molecules without fragmenting the treated tissue, which is highly sought to reduce the subsequent purification steps. The selection of the most appropriate extraction technique differs according to the type of waste and the targeted molecule to be extracted. However, although their efficiencies compared to conventional ones for the recovery of high-added value compounds from vegetal resources and by-products at laboratory and pilot scales, the described technologies are not yet ready for scaling up in food industry due to several reasons, mainly related to the equipment and installation costs. The current review is revising the potential of alternative extraction methodologies for the recovery of antioxidant bioactive compounds from vegetal resources. Conventional (solid liquid extraction, heating, grinding, etc) and non- conventional (pulsed electric fields, high voltage electrical discharges, pulsed ohmic heating, ultrasounds, microwave-assisted extractions, sub- and supercritical fluid extractions, as well as pressurized liquid extraction) methods have been applied for the extraction of high-added value compounds from resources of antioxidants.