Supercritical Carbon Dioxide Extraction of Molecules of Interest from Microalgae and Seaweeds

Abstract

The purpose of this paper is to guide lectors in the extraction of algal (microalgae and seaweeds) compounds using supercritical carbon dioxide (SC-CO 2 ) from dry biomass. It proposes a review of ∼30 articles dealing with the SC-CO 2 extraction of molecules of interest from microalgae and seaweeds. Among these papers, ∼20 are devoted to microalgae. The most extracted compounds are neutral lipids and antioxidants. Several operating conditions have been tested: pressures from 7.8 to 70 MPa, temperatures from 313.15 to 349.15 K, and CO 2 /algae mass ratio from 6 to 500. All extraction studies were performed at laboratory scale, with the masses of dry algae powder never exceeding 180 g. Extraction yields vary significantly with operating conditions: pressure seems to be the most influential parameter. The higher the pressure, the higher the yields and/or the faster the extraction kinetics. Temperature also has an influence, but its effect is dependent on pressure (retrograde behavior). Moreover, as expected, it is advised to work with a high CO 2 /algae mass ratio. From these works, it appears that, to perform an efficient extraction with SCÀCO 2 , the influence of the algae pretreatment is highly significant. The first step is a centrifugation. The resulting concentrated algal suspension must then undergo a drying operation, which is generally freeze-drying or low-temperature drying. Finally, the algae are crushed. Concerning the influence of crushing, the reported results show that, as expected, the smaller the particles, the more rapid the extraction kinetics and/or the higher the yields.

A review of extractions of seaweed hydrocolloids: Properties and applications

“…SFE-CO 2 gives a non-oxidizing atmosphere in extractions, thus can preventing extracts from degradation [102]. Among the identified literature dealing with seaweed and microalgae-SFE method extractions, the most extracted compounds are antioxidants and neutral lipids [115]. It was thought that, the extraction yields were significantly affected by pressure rather than temperature [115].…”

“…Among the identified literature dealing with seaweed and microalgae-SFE method extractions, the most extracted compounds are antioxidants and neutral lipids [115]. It was thought that, the extraction yields were significantly affected by pressure rather than temperature [115]. To date, there is no report regarding extraction of common used seaweed hydrocolloids with these 'green' methods.…”

Algae as production systems of bioactive compounds

“…In the literature many review papers were devoted to the use of novel extraction techniques to produce valuable bioactive compounds from algae, for example, SFE , MAE , UAE , EAE , PLE . These methods and compounds extracted from algae were also described in details in our previous review paper .…”

Method development in inverse modeling applied to supercritical fluid extraction of lipids

“…The applications of SFE span over a great field and has been extensively reviewed over the years [2][3][4], however much attention has been given to extraction from plant matrices [5]. It is worth emphasizing that the scales of SFE range from small scale within e.g.…”