Supercritical fluid extraction of algae enhances levels of biologically active compounds promoting plant growth (2025)

Valuable natural products from marine and freshwater macroalgae obtained from supercritical fluid extracts

Journal of Applied Phycology, 2017

The biologically active compounds (fatty acids, pigments, phenolics, and flavonoid content) were studied in supercritical fluid extracts from the biomass of marine (Ulva clathrata, Cladophora glomerata, Polysiphonia fucoides, and their multi-species mixture) and freshwater (C. glomerata) macroalgae. Different extraction techniques were used in order to compare differences in the biologically active compound composition of the macroalgal extracts. The results indicated that the saturated and unsaturated fatty acids ranged from C9:0 to C22:0. The analysis of differences in the composition of unsaturated to saturated fatty acids in extracts showed that palmitic acid (C16:0) and oleic acid (C18:1, n-9) reached the highest value not only in marine monospecies and multi-species biomass but also in the freshwater macroalga C. glomerata. When comparing the similarity between the concentration of fatty acids and the ratio of the concentration of unsaturated fatty acids to saturated in macroalgal extracts, we found small but not statistically significant variations in values between years (up to 10%). This is acceptable for applications as a stable raw material for industrial purposes. Significantly higher values of fatty acids, carotenoids, and chlorophylls were obtained in the case of SC-CO 2 extraction. The active ingredients of polyphenols, possessing antioxidant activity ranged from approximately 2-4%. Moreover, flavonoids represented less than 10% of the total content of polyphenolic compounds. The extraction efficiency of polyphenols was higher from a mixture of marine algae for the ultrasound-assisted extraction compared to freshwater. All these findings show that marine and freshwater macroalgae, as a raw material, have the optimal biologically active compounds composition for cosmetics.

Supercritical Algal Extracts: A Source of Biologically Active Compounds from Nature

Journal of Chemistry, 2015

The paper discusses the potential applicability of the process of supercritical fluid extraction (SFE) in the production of algal extracts with the consideration of the process conditions and yields. State of the art in the research on solvent-free isolation of biologically active compounds from the biomass of algae was presented. Various aspects related with the properties of useful compounds found in cells of microalgae and macroalgae were discussed, including their potential applications as the natural components of plant protection products (biostimulants and bioregulators), dietary feed and food supplements, and pharmaceuticals. Analytical methods of determination of the natural compounds derived from algae were discussed. Algal extracts produced by SFE process enable obtaining a solvent-free concentrate of biologically active compounds; however, detailed economic analysis, as well as elaboration of products standardization procedures, is required in order to implement the prod...

Supercritical CO 2 extraction of bioactive components from algae

Functional Ingredients from Algae for Foods and Nutraceuticals, 2013

Highlights  Supercritical fluid extracts optimization were done from radish leaves.  The best results were obtained at 35 ºC/400 bar and 40 ºC/400 bar.  Maturation of dendritic cells was not promoted being these extracts promising and interesting sources of antioxidative and anti-inflammatory agents.

Supercritical carbon dioxide extraction of compounds with pharmaceutical importance from microalgae

Inorg Chim Acta, 2003

Four microalgae (Botryococcus braunii, Chlorella vulgaris, Dunaliella salina, Arthrospira maxima) were object of supercritical CO2 extraction studies, which were carried out in a flow apparatus at temperatures between 313.1 and 333.1 K and pressures up to 35.0 MPa. The microalga Botryococcus braunii produces extracellular alkadienes. Supercritical extracts obtained at 313.1 K, and pressures of 12.5, 20.0 and 30.0 MPa, were golden and limpid, unlike those obtained with organic solvents. The hydrocarbons of this microalga were selectively extracted and this selectivity increased with pressure. The microalga Chlorella vulgaris is a carotenoid producer of canthaxanthin and astaxanthin. The extraction yields of lipids and carotenoids were compared for whole, crushed and slightly crushed algae at a pressure of 35.0 MPa and a temperature of 328.1 K. The yield of supercritical extraction of carotenoids was also compared at several conditions of pressure and temperature. It increased with pressure at constant temperature, remained practically constant with temperature, at pressures of 27.5 and 35.0 MPa, and decreased with temperature at 20.0 MPa. The third alga studied was the Dunaliella salina, which produces β-carotene in high yield. Natural β-carotene (cis and trans mixture) from this alga was submitted to supercritical carbon dioxide and it was assessed, at pressures up to 30.0 MPa and temperature of 313.1 K, that both isomers presented higher solubility than the synthetic trans-β-carotene and that the cis isomer was much more soluble in supercritical CO2 than the trans isomer. Moreover, it was shown that the cis/trans ratio, in the supercritical extracts, increased significantly, relatively to the original one in the microalga, when the Dunaliella was submitted to supercritical CO2. The cyanobacteria Arthrospira (Spirulina) maxima can produce in large amounts the γ-linolenic acid (GLA), C18:3 ω6. The yield and selectivity of the supercritical extraction, using CO2 and CO2 doped with ethanol, of the lipids and GLA were determined and compared with those obtained with organic solvents.Supercritical CO2 extraction studies of compounds with pharmaceutical importance from microalgae are presented. These studies involved the Botryococcus braunii, the Chlorella vulgaris, the Dunaliella salina and the cyanobacteria Arthrospira (Spirulina) maxima, which were used to obtain alkadienes, carotenoids (mainly canthaxanthin and astaxanthin), β-carotene and γ-linolenic acid, respectively.

Applications of supercritical CO2 extraction to microalgae and plants

Journal of Chemical Technology AND Biotechnology, 1995

A flow apparatus was constructed to carry out studies of supercritical fluid extraction in the temperature range 298.15-353.15 K and pressures up to 40 MPa. To test the apparatus, studies on the solubility of naphthalene in CO, at 308.15, 313.15 and 318.15 K and pressures up to 35 MPa were carried out. These experimental data were correlated through the Peng-Robinson equation of state. Samples of the microalgae Botryococcus braunii and Chlorella vulgaris which produce diolefines Cz,-C3 and carotenoids, respectively, were submitted to supercritical C 0 2 . The extraction yields for these compounds were studied and compared with those obtained using organic solvents. Supercritical COz was also used to produce extracts from rosemary leaves (Rosmarinus oficinalis L.), which were compared with those obtained by hexane extraction.

Recent Advances in Supercritical CO2 Extraction of Pigments, Lipids and Bioactive Compounds from Microalgae

Molecules

Supercritical CO2 extraction is a green method that combines economic and environmental benefits. Microalgae, on the other hand, is a biomass in abundance, capable of providing a vast variety of valuable compounds, finding applications in the food industry, cosmetics, pharmaceuticals and biofuels. An extensive study on the existing literature concerning supercritical fluid extraction (SFE) of microalgae has been carried out focusing on carotenoids, chlorophylls, lipids and fatty acids recovery, as well as the bioactivity of the extracts. Moreover, kinetic models used to describe SFE process and experimental design are included. Finally, biomass pretreatment processes applied prior to SFE are mentioned, and other extraction methods used as benchmarks are also presented.

Supercritical CO2 extraction of Aurantiochytrium sp. biomass for the enhanced recovery of omega-3 fatty acids and phenolic compounds

Journal of CO2 Utilization, 2020

The microalgae Aurantiochytrium sp. is a strong alternative source of ω-3 fatty acids, including docosahexaenoic acid (DHA). This work encompasses the optimization of SFE conditions to maximize the total extraction yield η () Total , DHA content (C DHA), total phenolics content (TPC), and antioxidant capacity (AOC) of the extracts produced from Aurantiochytrium sp. biomass. A full factorial experimental plan was performed, comprising three factors (pressure, temperature, and flow rate) and two levels (200−300 bar, 40−80°C, and 6-12 − g min 1 , respectively). The maximum and minimum experimental results were = η Total 2.1 and 13.4 wt.%, = C DHA 27.3 and 39.3 wt.%, TPC = 1.19 and 2.24 − mg g GAE extract 1 , and AOC = 0.3 and 1.4 − mg g TEAC extract 1. Under the studied experimental conditions, increasing pressure up to 300 bar is the optimum to rise both η Total and C DHA. Temperature increase from 40 to 80°C leads to opposing effects: it favors the concentration of phenolics in the supercritical extracts at the expenses of decreasing DHA content and total yield. Surface models were adjusted to η Total , C DHA and TPC data, and the goodness of the fits ranged from coefficients of determination of 0.752-0.711 (TPC) to 0.997-0.994 (C DHA). Under optimized conditions, supercritical extracts exhibited a DHA content more than 3.5fold richer than fish oil, and 7.9-fold richer than the best alternative microalgae species (Pavlova lutheri) found in the literature.

Extraction of carotenoids and chlorophyll from microalgae with supercritical carbon dioxide and ethanol as cosolvent

Journal of Separation Science, 2008

The work described here is based on a comparative study of carotenoids and fatty acids extracted from Synechococcus sp. with (1) pure supercritical CO 2 , (2) CO 2 with 5% (v/v) ethanol as cosolvent and ultrasound-assisted extraction using N, N-dimethylformamide (DMF). The effects of extraction conditions on supercritical CO 2 extraction with and within cosolvent were analyzed at different temperatures (40˚C, 50˚C and 60˚C) and pressures (200, 300 and 400 bars). SFE with CO 2 proved to be the most selective method for the extraction of β-carotene, but under these conditions the contents of zeaxanthin and fatty acids were only comparable to or lower than those obtained with techniques that use SFE cosolvent. The SFE technique with CO 2 and ethanol simultaneously extracted β-carotene and zeaxanthin and not only increased the concentrations of fatty acids obtained, but also helped to remove fatty acids (palmitoleic and linolenic acid) that were not obtained with pure CO 2 . Comparison of the supercritical technology with the ultrasound-assisted extraction (UAE) shows that the former technique is the most appropriate due to the fact that ethanol is generally regarded as a safe solvent in comparison to DMF.

Supercritical Fluids Extraction of Valuable Compounds from Algae: Future Perspectives and Challenges

Engineering Journal, 2018

Algae (macro and micro) can be used to produce several high-value metabolites to supply industries as cosmetics, additives and pigments, among others. Those metabolites can have physiological and nutritional benefits for human and animal health. However, the availability of high-value metabolites from algae is still unaffordable due to traditional extraction techniques and their requirements of energy and use of pollutant solvents. Recently, green extraction technologies for the extraction of high-value metabolites have become more desirable due to their sustainability and environmental benefits. Supercritical fluids extraction, as green extraction techniques, has been widely applied for extraction of high-value metabolites from algae. Here, the highlight of supercritical CO2 and subcritical water on the extraction of bioactive compounds from macro-and microalgae was presented. The perspective and challenge for using supercritical CO2 and subcritical water on the algae extraction were also concluded.

Extraction of carotenoids and lipids from algae by supercritical CO2 and subcritical dimethyl ether

The Journal of Supercritical Fluids, 2015

Algae contain lipids and functional compounds such as carotenoids. Especially, micoalgae are recently focused as a source of biofuel. To extract these components, organic solvent or supercritical carbon dioxide have been used. We have been developing wet extraction process using liquefied (subcritical) dimethyl ether (DME) as solvent at around 0.59MPa. The extraction process usually requires energy consuming drying and grinding process as in the case of supercritical CO 2. We have applied