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Joao A P Coutinho - One of the best experts on this subject based on the ideXlab platform.

Srecko Tomas - One of the best experts on this subject based on the ideXlab platform.

  • modelling of the process of Solid Liquid Extraction of total polyphenols from soybeans
    Czech Journal of Food Sciences, 2018
    Co-Authors: Stela Jokic, Ana Bucickojic, Mirela Planinic, Mate Bilic, Darko Velic, Srecko Tomas
    Abstract:

    In this study the influence of the solvent, temperature, and Extraction time on the extractability of total polyphenols from milled soybeans variety “Ika” was investigated. The study was performed in order to select the most suitable solvent (water ; 50, 60, 70, and 80% aqueous ethanol) for achieving the highest yield of total polyphenols. The most effective solvent (50% aqueous ethanol solution) was used for monitoring the kinetics and modelling of Solid-Liquid Extraction of total polyphenols from soybeans, average particle size 0.459 mm, at Solid-Liquid ratio of 20 ml/g (ratio of the solvent volume per g of raw material). The total polyphenols content in the soybean extract was determined spectrophotometrically using Folin-Ciocalteu micro-methods at 765 nm. The applicability of different mathematical models (Peleg, Page, and Logarithmic models) to describe the kinetics of the Solid-Liquid Extraction process of total polyphenols from soybeans was studied as well. The results exhibited a significant influence of the solvent and temperature on the kinetics and Extraction yield of total polyphenols from soybeans. The best Extraction yield of total polyphenols was obtained using 50% aqueous ethanol solution at 80 °C after 120 minutes (4.322 mg GAE/gdb). The Extraction yield of total polyphenols in soybean extracts increased by increasing the Extraction temperature and extending the duration of the Extraction process. The mathematical models applied showed a good agreement with the experimental results, which allows their application in modelling and optimisation of Solid-Liquid Extraction process for the Extraction of total polyphenols from soybeans.

  • temperature dependent kinetics of grape seed phenolic compounds Extraction experiment and model
    Food Chemistry, 2013
    Co-Authors: Ana Bucickojic, Mirela Planinic, Helena Sovova, Srecko Tomas
    Abstract:

    Abstract The kinetics of a batch Solid–Liquid Extraction of total phenolic compounds (PC) from milled grape seed ( Vitis vinifera L. cv. “Frankovka”) using 50% ethanol at different Extraction temperatures (25–80 °C) was studied. The maximum yield of PC was 0.13 kg GAE /kg db after 200 min of Extraction in agitated vessel at 80 °C. A new model based on the assumptions of a first order kinetics mechanism for the Solid–Liquid Extraction and a linear equilibrium at the Solid–Liquid interface was developed. The model involves the concept of broken and intact cells in order to describe two successive Extraction periods: a very fast surface washing process followed by slow diffusion of phenolic compounds from grape seeds to the solvent. The proposed model is suited to fit experimental data and to simulate the Extraction of phenolic compounds, which was confirmed by the correlation coefficient ( r  ⩾ 0.965), the root mean square error (RMSE ⩽ 0.003 kg GAE /kg db ) and the mean relative deviation modulus ( E  ⩽ 2.149%). The temperature influenced both equilibrium partition coefficients of phenolic compounds and transport properties, which is manifested by a relatively high value of activation energy (23–24) kJ/mol and by values of effective diffusivity in seed particles.

  • study of Solid Liquid Extraction kinetics of total polyphenols from grape seeds
    Journal of Food Engineering, 2007
    Co-Authors: Ana Bucickojic, Mirela Planinic, Srecko Tomas, Mate Bilic, Darko Velic
    Abstract:

    Abstract Grape seeds are a waste by-product obtained after wine or juice making and present a good source of functional compounds, such as polyphenols. Extraction is a very important step for later use of phenolic components. The effect of different temperatures and Solid–Liquid ratios on the Solid–Liquid Extraction yield of total polyphenols and the effect of four classes of particle size on the Extraction kinetics of total polyphenols with 50% of aqueous ethanol were studied. Temperature, Solid–Liquid ratio and milling degree had positive influence on Extraction rate and extent of Extraction. The 1.47–6.68% of total polyphenols per dry matter of grape seeds was extracted during 200 min. Extraction kinetics was estimated using non-experimental two-parameter equation – modified Peleg’s model. Results showed a good prediction of Peleg’s model for Extraction kinetics in all experiments ( ρ  > 0.994), which gave the possibility for estimation of initial rate and extent of Solid–Liquid Extraction.

Nicolas Schaeffer - One of the best experts on this subject based on the ideXlab platform.

Maria Pilar Almajano - One of the best experts on this subject based on the ideXlab platform.

  • continuous or batch Solid Liquid Extraction of antioxidant compounds from seeds of sterculia apetala plant and kinetic release study
    Molecules, 2018
    Co-Authors: Federica Mosca, Gador Indra Hidalgo, Juliana Villasante, Maria Pilar Almajano
    Abstract:

    This work has been intended to investigate the antioxidant properties of compounds extracted from seeds of Sterculia apetala (a plant from Central America) in order to add further results to the relatively poor existing literature on the beneficial properties of this plant. Different Extraction methodologies were used such as batch or continuous Extraction conditions using water or ethanol 50% as solvents. The kinetic study has allowed estimation of the effective diffusion coefficients in a continuous Solid-Liquid Extraction, highlighting the strict dependence of the diffusion rate and temperature and kind of solvent, showing the highest diffusion rate with ethanol 50% at 60 °C. The comparison between different techniques and two solvents led to the selection of water as the best Extraction solvent while batch mechanically-agitated Extraction was the most efficient mode, with the benefits of use of an environmental-friendly solvent and reduction in process time to achieve a high amount of extracted phenolic compounds. The analysis techniques used were ABTS and Folin-Ciocalteau methods to investigate the antioxidant activity and quantify the Total Phenolic Content (TPC) respectively. Also, different fatty acids were extracted from Sterculia apetala seeds and analysed by Gas Chromatography in order to quantify other interesting chemical species besides antioxidants.

  • Continuous or Batch Solid-Liquid Extraction of Antioxidant Compounds from Seeds of Sterculia apetala Plant and Kinetic Release Study
    MDPI AG, 2018
    Co-Authors: Federica Mosca, Gador Indra Hidalgo, Juliana Villasante, Maria Pilar Almajano
    Abstract:

    This work has been intended to investigate the antioxidant properties of compounds extracted from seeds of Sterculia apetala (a plant from Central America) in order to add further results to the relatively poor existing literature on the beneficial properties of this plant. Different Extraction methodologies were used such as batch or continuous Extraction conditions using water or ethanol 50% as solvents. The kinetic study has allowed estimation of the effective diffusion coefficients in a continuous Solid-Liquid Extraction, highlighting the strict dependence of the diffusion rate and temperature and kind of solvent, showing the highest diffusion rate with ethanol 50% at 60 °C. The comparison between different techniques and two solvents led to the selection of water as the best Extraction solvent while batch mechanically-agitated Extraction was the most efficient mode, with the benefits of use of an environmental-friendly solvent and reduction in process time to achieve a high amount of extracted phenolic compounds. The analysis techniques used were ABTS and Folin-Ciocalteau methods to investigate the antioxidant activity and quantify the Total Phenolic Content (TPC) respectively. Also, different fatty acids were extracted from Sterculia apetala seeds and analysed by Gas Chromatography in order to quantify other interesting chemical species besides antioxidants

Ana Bucickojic - One of the best experts on this subject based on the ideXlab platform.

  • modelling of the process of Solid Liquid Extraction of total polyphenols from soybeans
    Czech Journal of Food Sciences, 2018
    Co-Authors: Stela Jokic, Ana Bucickojic, Mirela Planinic, Mate Bilic, Darko Velic, Srecko Tomas
    Abstract:

    In this study the influence of the solvent, temperature, and Extraction time on the extractability of total polyphenols from milled soybeans variety “Ika” was investigated. The study was performed in order to select the most suitable solvent (water ; 50, 60, 70, and 80% aqueous ethanol) for achieving the highest yield of total polyphenols. The most effective solvent (50% aqueous ethanol solution) was used for monitoring the kinetics and modelling of Solid-Liquid Extraction of total polyphenols from soybeans, average particle size 0.459 mm, at Solid-Liquid ratio of 20 ml/g (ratio of the solvent volume per g of raw material). The total polyphenols content in the soybean extract was determined spectrophotometrically using Folin-Ciocalteu micro-methods at 765 nm. The applicability of different mathematical models (Peleg, Page, and Logarithmic models) to describe the kinetics of the Solid-Liquid Extraction process of total polyphenols from soybeans was studied as well. The results exhibited a significant influence of the solvent and temperature on the kinetics and Extraction yield of total polyphenols from soybeans. The best Extraction yield of total polyphenols was obtained using 50% aqueous ethanol solution at 80 °C after 120 minutes (4.322 mg GAE/gdb). The Extraction yield of total polyphenols in soybean extracts increased by increasing the Extraction temperature and extending the duration of the Extraction process. The mathematical models applied showed a good agreement with the experimental results, which allows their application in modelling and optimisation of Solid-Liquid Extraction process for the Extraction of total polyphenols from soybeans.

  • temperature dependent kinetics of grape seed phenolic compounds Extraction experiment and model
    Food Chemistry, 2013
    Co-Authors: Ana Bucickojic, Mirela Planinic, Helena Sovova, Srecko Tomas
    Abstract:

    Abstract The kinetics of a batch Solid–Liquid Extraction of total phenolic compounds (PC) from milled grape seed ( Vitis vinifera L. cv. “Frankovka”) using 50% ethanol at different Extraction temperatures (25–80 °C) was studied. The maximum yield of PC was 0.13 kg GAE /kg db after 200 min of Extraction in agitated vessel at 80 °C. A new model based on the assumptions of a first order kinetics mechanism for the Solid–Liquid Extraction and a linear equilibrium at the Solid–Liquid interface was developed. The model involves the concept of broken and intact cells in order to describe two successive Extraction periods: a very fast surface washing process followed by slow diffusion of phenolic compounds from grape seeds to the solvent. The proposed model is suited to fit experimental data and to simulate the Extraction of phenolic compounds, which was confirmed by the correlation coefficient ( r  ⩾ 0.965), the root mean square error (RMSE ⩽ 0.003 kg GAE /kg db ) and the mean relative deviation modulus ( E  ⩽ 2.149%). The temperature influenced both equilibrium partition coefficients of phenolic compounds and transport properties, which is manifested by a relatively high value of activation energy (23–24) kJ/mol and by values of effective diffusivity in seed particles.

  • study of Solid Liquid Extraction kinetics of total polyphenols from grape seeds
    Journal of Food Engineering, 2007
    Co-Authors: Ana Bucickojic, Mirela Planinic, Srecko Tomas, Mate Bilic, Darko Velic
    Abstract:

    Abstract Grape seeds are a waste by-product obtained after wine or juice making and present a good source of functional compounds, such as polyphenols. Extraction is a very important step for later use of phenolic components. The effect of different temperatures and Solid–Liquid ratios on the Solid–Liquid Extraction yield of total polyphenols and the effect of four classes of particle size on the Extraction kinetics of total polyphenols with 50% of aqueous ethanol were studied. Temperature, Solid–Liquid ratio and milling degree had positive influence on Extraction rate and extent of Extraction. The 1.47–6.68% of total polyphenols per dry matter of grape seeds was extracted during 200 min. Extraction kinetics was estimated using non-experimental two-parameter equation – modified Peleg’s model. Results showed a good prediction of Peleg’s model for Extraction kinetics in all experiments ( ρ  > 0.994), which gave the possibility for estimation of initial rate and extent of Solid–Liquid Extraction.