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Carmelo Garcia Barroso - One of the best experts on this subject based on the ideXlab platform.

  • Microwave Assisted Extraction of soy isoflavones
    Analytica Chimica Acta, 2007
    Co-Authors: Mauricio A Rostagno, Miguel Palma, Carmelo Garcia Barroso
    Abstract:

    Abstract A fast and reliable analytical method using Microwave Assisted Extraction has been developed. Several Extraction solvents (methanol (MeOH) and ethanol (EtOH), 30–70% in water and water), temperatures (50–150 °C), Extraction solvent volume, as well as the sample size (1.0–0.1 g) and Extraction time (5–30 min) were studied for the optimization of the Extraction protocol. The optimized Extraction conditions for quantitative recoveries were: 0.5 g of sample, 50 °C, 20 min and 50% ethanol as extracting solvent. No degradation of the isoflavones was observed using the developed Extraction protocol and a high reproducibility was achieved (>95%).

  • investigation on phenolic compounds stability during Microwave Assisted Extraction
    Journal of Chromatography A, 2007
    Co-Authors: Ali Liazid, Miguel Palma, Jamal Brigui, Carmelo Garcia Barroso
    Abstract:

    The stability of 22 phenolic compounds of different families (benzoic acids, benzoic aldehydes, cinnamic acids, catechins, coumarins, stilbens and flavonols) has been studied under conditions of Microwave-Assisted Extraction. The influence on the stability affected by the working temperature between 50 and 175 °C has been evaluated, and it has been concluded that all the compounds studied are stable up to 100 °C, whereas at 125 °C there is significant degradation of epicatechin, resveratrol and myricetin. Conclusions have been drawn on the relationship between the chemical structure and the stability of the compounds; it has been found that those that have a greater number of hydroxyl-type substituents are more easily degraded under the Extraction conditions.

Hanqi Zhang - One of the best experts on this subject based on the ideXlab platform.

  • dynamic Microwave Assisted Extraction of flavonoids from herba epimedii
    Separation and Purification Technology, 2008
    Co-Authors: Ligang Chen, Lan Ding, Huarong Zhang, Juan Li, Chenling Qu, Hanqi Zhang
    Abstract:

    Abstract An apparatus for Extraction of flavonoids from Herba Epimedii has been constructed which utilizes a Microwave technique for heating in a dynamic mode. A TM 010 Microwave resonance cavity was applied to concentrate the Microwave energy; the power needed to achieve efficient Extraction was significantly reduced. The method has been compared with other Extraction methods, such as pressurized Microwave-Assisted Extraction (PMAE), ultrasonic Extraction (UE), heat reflux Extraction (RE) and Soxhlet Extraction (SOX). The four flavonoids in extract were identified by HPLC–MS. The influence of Extraction parameters on the Extraction yield of flavonoids has been evaluated by comparison with the peak areas of HPLC-DAD spectra in the different Extraction methods. The results showed that the Extraction yield of flavonoids in Herba Epimedii obtained by dynamic Microwave-Assisted Extraction (DMAE) was higher than that obtained by UE, RE and SOX, and the Extraction time is dramatically reduced. The Extraction yield obtained by DMAE is similar to that obtained by PMAE. But the flavonoids in Herba Epimedii would not decompose easily when increasing the Extraction time in DMAE. This is the benefit of dynamic Extraction system which can transfer the analytes extracted from the sample matrix with flowed fresh solvent to the out of Extraction vessel.

Baozhen Song - One of the best experts on this subject based on the ideXlab platform.

  • dynamic Microwave Assisted Extraction of flavonoids from saussurea medusa maxim cultured cells
    Biochemical Engineering Journal, 2006
    Co-Authors: Baozhen Song
    Abstract:

    An approach for automated, continuous and rapid Extraction of flavonoids from Saussurea medusa Maxim dried cell cultures has been developed in a new-designed dynamic Microwave-Assisted Extraction system. The main factors affecting the Extraction process namely power of Microwave irradiation, liquid/solid ratio, flow rate of solvent and irradiation time were optimized. The yield of flavonoids reached 4.97% in 60 min under the optimum Microwave-Assisted Extraction conditions: 1200 W of radiation power, 50:1 (v/w) of the liquid/solid ratio, and 50 ml s(-1) of solvent flow rate. The dynamic Microwave-Assisted Extraction showed obvious advantages in short duration and high efficiency to extract flavonoids without causing degradation of target components from the S. medusa dried cell cultures in comparison with the dynamic solvent Extraction without Microwave assistance. (c) 2006 Elsevier B.V. All rights reserved.

Michael Komaitis - One of the best experts on this subject based on the ideXlab platform.

  • application of Microwave Assisted Extraction to the fast Extraction of plant phenolic compounds
    Lwt - Food Science and Technology, 2008
    Co-Authors: Charalampos Proestos, Michael Komaitis
    Abstract:

    Abstract The analysis of phenolic compounds in plants attracts considerable attention. Conventional (reflux) Extraction as well as Microwave-Assisted Extraction of phenolic substances from aromatic plants using different solvents has been studied. RP-HPLC with UV detection was employed for the analysis of phenolic compounds. Total phenolic compounds were determined by the Folin–Ciocalteu assay. The amount of extractable phenolic substances for this method decreased with decreasing polarity of the solvent in the order water, 60% methanol, 60% acetone, and ethyl acetate/water (60:30, v/v) by using the conventional method. When Microwave-Assisted Extraction was performed, the previous order was changed to 60% acetone, 60% methanol, water and ethyl acetate/water. The HPLC results have shown similar solvent effect for the two Extraction methods. It was also proved that Microwave-Assisted Extraction is a more effective technique compared to the conventional method. The Extraction time was reduced, less solvent was used and the amount of extracted phenolic compounds was increased.

Francois Mesnard - One of the best experts on this subject based on the ideXlab platform.

  • Microwave Assisted Extraction of the main phenolic compounds in flaxseed
    Phytochemical Analysis, 2007
    Co-Authors: Vickram Beejmohun, Ophelie Fliniaux, Eric Grand, Frederic Lamblin, Lamine Bensaddek, Philippe Christen, Jose Kovensky, Marcandre Fliniaux, Francois Mesnard
    Abstract:

    A Microwave-Assisted Extraction (MAE) method has been applied for the first time to the Extraction of the main lignan, secoisolariciresinol diglucoside (SDG), and the two most concentrated hydroxycinnamic acid glucosides in flaxseed. The effects of Microwave power, Extraction time and alkaline treatment were investigated. It was shown that a 3 min MAE resulted in an SDG content of 16.1 ± 0.4 mg/g, a p-coumaric acid glucoside content of 3.7 ± 0.2 mg/g and a ferulic acid glucoside content of 4.1 ± 0.2 mg/g. These values were compared with those obtained using conventional Extraction methods and the results demonstrated that MAE was more effective in terms of both yield and time consumption. Copyright © 2007 John Wiley & Sons, Ltd.