Characterization on Phenolic Acids and Antioxidant Activity of Chlorella sp. Microalgae using Subcritical Water Extraction (original) (raw)
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Journal of Applied Phycology, 2017
Microalgae and especially green algae are microorganisms that are used in a wide range of industrial applications of high economic interest, such as fish farming, food, cosmetics, pharmaceuticals, and biofuel. In this study, the green microalga Chlorella vulgaris was examined as raw material for the recovery of bioactive compounds and the production of multifunctional extracts. Firstly, the drying of raw biomass, which is a crucial pre-treatment stage, was examined with freeze-drying having the best performance. Ultrasound assisted extraction (UAE) applying various solvent systems was studied under optimized conditions. For the untreated microalgal biomass, ethanol was indicated as the preferable solvent, whereas on dried samples, water was a more suitable solvent. UV-Vis spectrometry and high-performance liquid chromatography (HPLC) were used for the determination of total carotenoid, chlorophyll, and protein content in the raw materials, extracts, and extraction residues. Moreover, the suitability of drying technique and extraction solvent system was evaluated according to the obtained antiradical activity of the relevant treated biomass and extraction samples using the DPPH method.
Molecules
Microalgae contain an abundance of valuable bioactive compounds such as chlorophylls, carotenoids, and phenolics and, consequently, present great commercial interest. The aim of this work is the study and optimization of recovering the aforementioned components from the microalgae species Chlorella vulgaris through conventional extraction in a laboratory-scale apparatus using a “green” mixture of ethanol/water 90/10 v/v. The effect of three operational conditions—namely, temperature (30–60 °C), duration (6–24 h) and solvent-to-biomass ratio (20–90 mLsolv/gbiom), was examined regarding the extracts’ yield (gravimetrically), antioxidant activity, phenolic, chlorophyll, and carotenoid contents (spectrophotometric assays), as well as concentration in key carotenoids, i.e., astaxanthin, lutein, and β-carotene (reversed-phase–high-performance liquid chromatography (RP–HPLC)). For this purpose, a face-centered central composite design (FC-CCD) was employed. Data analysis resulted in the op...
Journal of Applied Phycology, 2019
The interest in using marine organisms as a source of novel bioactive compounds has increased recently, reinforcing the need to find efficient and cost-effective methods to extract these biocompounds. Thus, the present study has focused on evaluating four solvent systems and three extraction methods to obtain extracts of three macroalgae (Gracilaria sp., Fucus vesiculosus, and Ulva rigida) and two microalgae (Chlorella sp. and Nannochloropsis gaditana). The extracts were evaluated regarding yield, phenolic content, and potential antioxidant activity. Results showed that a lower organic solvent:water ratio increased macroalgae, but not microalgae, biomass extraction efficiency. Levels of total phenolics, ortho-diphenols and flavonoids were highly influenced by algae material and solvent system applied. Strong 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) scavenging activity was obtained with ethanol:water, 80:20 (E80:20) microalgal extracts, while no visible trend was detected for macroalgae extracts. However, methanolic extracts were the most effective in scavenging of 2,2-diphenyl-1picrylhydrazyl (DPPH). In macroalgae, a high positive correlation was observed between phenolic content and antioxidant capacity while in microalgae, the opposite was verified, suggesting that in microalgae, phenolic compounds are not the main contributors to the observed antioxidant capacity.
Separation Science and Technology, 2009
Water in hydrothermal condition has been used for extraction of nutraceutical compounds from Chlorella vulgaris. Hydrothermal extraction was carried out in a semi-batch and a batch extractor at various temperatures (120-200 C), pressures (2-10 MPa), and extraction times (30-300 min) to extract antioxidant and antibacterial compounds. The effect of extraction condition on the yield of extract was investigated. The antioxidant and antibacterial activity of extracts obtained by hydrothermal extraction were examined. The increasing extraction temperature resulted in higher antioxidant activity, but lower antimicrobial activity. As comparison with hot water extraction, the antioxidant activity of extract obtained by hydrothermal extraction was higher than that obtained by hot water extraction, but the antibacterial activity of the extract obtained by hydrothermal extraction was lower.
Phytochemical Screening and antioxidant activity of Chlorella vulgaris
Delta Journal of Science
Microalgae are rich sources of structurally novel and biologically active metabolites. Primary and secondary metabolites produced by these organisms which have drawn interest of the pharmaceutical industries. In this regard, the study aimed to screening of phytochemical compounds and evaluate the total phenolic content and the antioxidant activity of Chlorella vulgaris. The antioxidant activity of C. vulgaris was tested by 2,2-diphenyl-1-picrylhydrazyl DPPH radical scavenging method, reducing power assay and the total antioxidant capacity (TAC). The phytochemical screening exhibited the presence of alkaloids, flavonoids and phenols in all tested solvents which exhibited several biological activities. Among the different solvents, acetone extract exhibited the highest scavenging activity with (50.81%). Also, showed reducing power activity estimated with 1.95 mg AAE/g DW and antioxidant capacity recorded 2.58 mg AAE/g DW. In addition, considerable amount of the total phenolic has been detected in acetone extract recording 3.17 mg GAE/g DW. The results revealed that there is a strong correlation between the antioxidant activity assays and the phenolic content of Chlorella vulgaris. Thus, the green microalga Chlorella vulgaris in dietary supplements will be effective mediator in scavenging free radicals as it contains wide variety of bioactive compounds.
Applied Sciences
The current study assessed antioxidants contents (total phenolics and total flavanoids, β-carotene and lycopene) present in Chlorella vulgaris (C. vulgaris) cultivated in low cost media and their free radical scavenging activities. Microalgae was cultured using Bold basal medium (BBM) as a control, 5% banana stem compost (BCM) and aquaculture wastewater supplemented with 1.0 g/L NPK (ANM). The free radical scavenging ability was analysed using 1,1-diphenyl -2-picrylhydrazyl assay. Cells grown on BCM resulted in higher (13.73 ± 0.121%) extraction yield than in other media. The phenolic (8.53 ± 0.10 mg/g GAE) and lycopene (0.29 ± 0.008 mg/g) content were highest in cells grown on BCM and BBM, respectively. Microalgae cultured in ANM displayed higher (547.023 ± 34.703 mg/g RE) flavanoid and β-carotene (2.887 ± 0.121 mg/g) content than in other media. Furthermore, cells cultivated in BCM showed highest (97.87 ± 0.088%) scavenging activity than in BBM. These results indicated that the BC...
International Journal of Food Science and Technology, 860-869, 48(4), 2013
The efficiencies of pressurised liquid extraction (PLE) and a traditional solid–liquid extraction (SLE) at extracting antioxidant polyphenols from Irish macroalgae Ascophyllum nodosum, Pelvetia canaliculata, Fucus spiralis and Ulva intestinalis were compared. PLE was more effective for extracting polyphenols with acetone/water (80:20); however, when food-friendly solvents of ethanol/water (80:20) and water were employed, SLE resulted in higher phenolic content in brown macroalgal extracts. For example, the Fucus spiralis SLE water and ethanol/water extracts displayed total phenolic contents (TPCs) of 130.58 ± 2.78 and 142.81 ± 1.77 μg phloroglucinol equivalents (PGE) mg−1 sample, respectively, compared with TPCs of 90.79 ± 1.16 and 124 ± 6.54 μg PGE mg−1 sample for the corresponding PLE extracts. All SLE aqueous ethanolic macroalgal extracts possessed higher DPPH radical scavenging abilities (RSA) and ferric reducing antioxidant power (FRAP) than their PLE equivalents. This study indicates that the application of high extraction temperatures (50–200 °C) and pressures (500–3000 psi) used in PLE does not enhance the antioxidant activities of macroalgal extracts relative to SLE extraction. The ability to produce antioxidant food-friendly macroalgal extracts using SLE could represent significant cost reductions on an industrial scale further enhancing the potential of macroalgal polyphenols to be used in functional food preparations.
Biocatalysis and agricultural biotechnology, 2018
The purpose of this study was to see if the microalgae species Chlorella miniata possess an antioxidant and antiinflammatorypotential and to see if there is a correlation between the cultivation conditions and these potentials. Forthis purpose, cultivation of the algae under different growth conditions had been carried out; afterwards the soxhletextraction of the produced biomass had been completed. Lastly the assays of Trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant capacity (FARP), total antioxidant capacity (TAO), xanthine oxidase inhibition, and hyaluronidase inhibition were studied using extracts of microalgae obtained from the different cultivation parameters. It's important to mention that this was the first study using these assays on species of Chlorella miniata and the first that utilized the cultivation parameters on microalgae. The results were, 22,91 mg/g algae TEAC, 776,70 mg/g algae gallic acid equivalent of FRAP and 37,07% xanthine oxidase inhibition with a concentration of 10,5 mg algae per ml ethanol, 65,39% of hyaluronidase inhibition with a concentration of 0,9 mg algae per ml ethanol. The effects of the cultivation parameters on these assays and the Lc MS/MS analyses for various phenolic compounds in the extracts were also a part of the study.
Food Chemistry, 2007
In order to identify new sources of safe and inexpensive antioxidants, the antioxidant capacity and total phenolic content of different fractions of 23 microalgae were evaluated, using Trolox equivalent antioxidant capacity assay and the Folin–Ciocalteu method, respectively. The microalgae were extracted using hexane, ethyl acetate and water by a three-step sequential extraction procedure. Most of these microalgae were evaluated for
2020
The aim of this study is to investigate the phytochemical constituents of the microalga Chlorella vulgaris using two different cultivation conditions and validate their antioxidant, antiviral, antihyperlipidemic as well as cytotoxic effects against different cell lines; prostate cancer cell line (PC3), hepatocellular carcinoma (HePG2), caucasian breast adenocarcinoma (MCF7) and normal skin fibroblast (BJ1). Alga was heterotrophically grown with a full nitrogen content of the growth medium in both normal and stress growth conditions. Stress was performed by potassium starvation, salting out and ferric chloride in the presence of sodium acetate. Crude protein content for vegetative and stressed C. vulgaris resulted 46% and 30%, respectively. The total carbohydrates of vegetative and stressed types were 25% and 18%, respectively, while the amount of the isolated polysaccharides was 22.6 and 16.5%. Rhamnose (21.27 and 14.89%) and galactose (17.63 and 15.59%) were found to be the main su...