Plants, seaweeds, microalgae and food by-products as natural sources of functional ingredients obtained using pressurized liquid extraction and supercritical fluid extraction

We present an up-to-date review on the use of subcritical and supercritical extraction processes to obtain functional bioactive compounds from different natural matrices, including plants, food by-products, seaweeds and microalgae. The ever-increasing demand for natural bioactive compounds is fostering the search for new underexplored natural sources for this kind of components. The use of advanced sustainable extraction techniques to extract and to purify the bioactive compounds is of the utmost importance. Pressurized liquid extraction and supercritical fluid extraction are two of this kind of technique that have already been widely employed to recover bioactives from different sources. We comment on the most relevant recent developments and improvements involving these natural sources and discuss the future evolution of the use of these two extraction processes.