Extraction Of Phenolic Compounds From Pepper-rosmarin (lippia Sidoides Cham.) Leaves By Sequential Extraction In Fixed Bed Extractor Using Supercritical Co2, Ethanol And Water As Solvents

Extraction of bioactive compounds requires frequent changes in the extraction techniques due to the quality requirements in the food, pharmaceutical and cosmetic industries. The compounds of the polyphenolic family represent an important group of bioactive compounds in food, and are present in various types of plants, including Lippia sidoides Cham., also known as pepper-rosmarin, an aromatic plant with therapeutic properties. Thus, this study aimed to investigate the sequential extraction (in fixed bed and high pressure) of bioactive compounds from L. sidoides leaves, using supercritical carbon dioxide, ethanol, and water as solvents and, compare the global yield, total phenolics, total flavonoids, and antioxidant activity of extracts obtained from sequential extraction with the extracts obtained by one-step extraction in fixed bed (high pressure) and by conventional extraction. The results showed that the combination of extraction processes is an effective method to obtain extracts with different compositions and functionalities. Overall, the ethanolic extraction in fixed bed and the three-step sequential extraction showed the best results in terms of global yield, and content and yield of total phenolics and flavonoids. The ethanol extracts exhibited the best antioxidant activity, which may be related to the presence of phenolic compounds

Extraction Of Phenolic Compounds From Pitanga (eugenia Uniflora L.) Leaves By Sequential Extraction In Fixed Bed Extractor Using Supercritical Co 2, Ethanol And Water As Solvents

With the goal of maximizing the extraction yield of phenolic compounds from pitanga leaves (Eugenia uniflora L.), a sequential extraction in fixed bed was carried out in three steps at 60 C and 400 bar, using supercritical CO 2 (non-polar) as solvent in a first step, followed by ethanol (polarity: 5.2) and water (polarity: 9.0) in a second and third steps, respectively. All extracts were evaluated for global extraction yield, concentration and yield of both polyphenols and total flavonoids and antioxidant activity by DPPH method (in terms of EC50). The nature of the solvent significantly influenced the process, since the extraction yield increased with solvent polarity. The aqueous extracts presented higher global extraction yield (22%), followed by ethanolic (16%) and supercritical extracts (5%). The study pointed out that the sequential extraction process is the most effective in terms of global extraction yield and yield of polyphenols and total flavonoids, because it produced the more concentrated extracts on phenolic compounds, since the supercritical ethanolic extract presented the highest phenolics content (240.5 mg GAE/g extract) and antioxidant capacity (EC 50 = 9.15 μg/mL). The most volatile fraction from the supercritical extract, which is similar to the essential oils obtained by steam distillation or hydrodistillation, presented as major compounds the germacrenos D and B + bicyclogermacrene (40.75%), selina-1,3,7(11)-trien-8-one + selina-1,3,7(11)-trien-8-one epoxide (27.7%) and trans-caryophyllene (14.18%). © 2013 Elsevier B.V.86414Auricchio, M.T., Bacchi, E.M., Folhas de Eugenia uniflora L. 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Extracts From The Leaves Of Baccharis Dracunculifolia Obtained By A Combination Of Extraction Processes With Supercritical Co 2, Ethanol And Water

One and two step extraction processes were used to obtain extracts from two samples of alecrim do campo leaves (Baccharis dracunculifolia L.). In the one step process, supercritical carbon dioxide (scCO 2), ethanol and water were used as solvents. In the two step process, scCO 2 was used as a solvent in the first step followed by ethanol or water as the solvent in a second step on the residue resulting from scCO 2 extraction. Extraction yields, total polyphenol, total flavonoid and Artepillin C contents, antioxidant activity by DPPH radical scavenging and β-carotene bleaching methods were measured in all extracts. The supercritical extract showed a higher concentration and yield of Artepillin C, low antioxidant activity by the DPPH method and high antioxidant activity by the β-carotene method. In general the aqueous and ethanol extracts were more concentrated in polyphenol compounds and a second extraction step produced high yields with high concentrations of phenolic compounds. © 2011 Elsevier B.V. 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