TY  - JOUR
AU  - Ivanović, Jasna
AU  - Meyer, Florian
AU  - Mišić, Dušan
AU  - Ašanin, Jelena
AU  - Jaeger, Philip
AU  - Žižović, Irena
AU  - Eggers, Rudolf
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5700
AB  - Multiplication and spreading of multiresistant pathogenic bacteria that cause fatal infections in humans and animals have boosted research on implementation of newer technologies for producing natural substances with strong antibacterial activities. In this study, SFE from lichen Usnea barbata was investigated for different pre-treatment methods with respect to extracts yield, usnic acid recovery and antibacterial activity against more than thirty methicillin resistant staphylococci strains. Extraction of U. barbata with subcritical carbon dioxide was studied as well. Extraction yield, usnic acid content and antibacterial activity of the extracts were strongly affected by the pre-treatment method. Intensive pre-treatment methods such as flaking and cutting + grinding caused a considerable comminution of the lichen thallus and enabled high extraction yields. On the other hand, mild pre-treatment of the lichen such as impact + shearing enabled isolation of extracts with lower MIC values. Experimental results indicated that extraction with liquid carbon dioxide at 30 MPa and 25 degrees C was the most favorable condition at which a satisfactory high extraction yield was obtained (2.08%). Extract isolated with liquid carbon dioxide had a high usnic acid content in the extract (632 g/kg) and a very strong antibacterial activity (average MIC of 19.11 mu g/mL). Antibacterial activity of all the extracts against tested strains was comparable to the pure usnic acid or even stronger. This study indicated a potential use of the supercritical extracts of U. barbata in pharmaceutical formulations for treatment of infections caused by staphylococci.
PB  - Elsevier, Amsterdam
T2  - Journal of Supercritical Fluids
T1  - Influence of different pre-treatment methods on isolation of extracts with strong antibacterial activity from lichen Usnea barbata using carbon dioxide as a solvent
EP  - 9
SP  - 1
VL  - 76
DO  - 10.1016/j.supflu.2013.01.005
ER  - 

@article{
author = "Ivanović, Jasna and Meyer, Florian and Mišić, Dušan and Ašanin, Jelena and Jaeger, Philip and Žižović, Irena and Eggers, Rudolf",
year = "2013",
abstract = "Multiplication and spreading of multiresistant pathogenic bacteria that cause fatal infections in humans and animals have boosted research on implementation of newer technologies for producing natural substances with strong antibacterial activities. In this study, SFE from lichen Usnea barbata was investigated for different pre-treatment methods with respect to extracts yield, usnic acid recovery and antibacterial activity against more than thirty methicillin resistant staphylococci strains. Extraction of U. barbata with subcritical carbon dioxide was studied as well. Extraction yield, usnic acid content and antibacterial activity of the extracts were strongly affected by the pre-treatment method. Intensive pre-treatment methods such as flaking and cutting + grinding caused a considerable comminution of the lichen thallus and enabled high extraction yields. On the other hand, mild pre-treatment of the lichen such as impact + shearing enabled isolation of extracts with lower MIC values. Experimental results indicated that extraction with liquid carbon dioxide at 30 MPa and 25 degrees C was the most favorable condition at which a satisfactory high extraction yield was obtained (2.08%). Extract isolated with liquid carbon dioxide had a high usnic acid content in the extract (632 g/kg) and a very strong antibacterial activity (average MIC of 19.11 mu g/mL). Antibacterial activity of all the extracts against tested strains was comparable to the pure usnic acid or even stronger. This study indicated a potential use of the supercritical extracts of U. barbata in pharmaceutical formulations for treatment of infections caused by staphylococci.",
publisher = "Elsevier, Amsterdam",
journal = "Journal of Supercritical Fluids",
title = "Influence of different pre-treatment methods on isolation of extracts with strong antibacterial activity from lichen Usnea barbata using carbon dioxide as a solvent",
pages = "9-1",
volume = "76",
doi = "10.1016/j.supflu.2013.01.005"
}

Ivanović, J., Meyer, F., Mišić, D., Ašanin, J., Jaeger, P., Žižović, I.,& Eggers, R.. (2013). Influence of different pre-treatment methods on isolation of extracts with strong antibacterial activity from lichen Usnea barbata using carbon dioxide as a solvent. in Journal of Supercritical Fluids
Elsevier, Amsterdam., 76, 1-9.
https://doi.org/10.1016/j.supflu.2013.01.005

Ivanović J, Meyer F, Mišić D, Ašanin J, Jaeger P, Žižović I, Eggers R. Influence of different pre-treatment methods on isolation of extracts with strong antibacterial activity from lichen Usnea barbata using carbon dioxide as a solvent. in Journal of Supercritical Fluids. 2013;76:1-9.
doi:10.1016/j.supflu.2013.01.005 .

Ivanović, Jasna, Meyer, Florian, Mišić, Dušan, Ašanin, Jelena, Jaeger, Philip, Žižović, Irena, Eggers, Rudolf, "Influence of different pre-treatment methods on isolation of extracts with strong antibacterial activity from lichen Usnea barbata using carbon dioxide as a solvent" in Journal of Supercritical Fluids, 76 (2013):1-9,
https://doi.org/10.1016/j.supflu.2013.01.005 . .

TY  - JOUR
AU  - Meyer, Florian
AU  - Stamenić, Marko
AU  - Žižović, Irena
AU  - Eggers, Rudolf
PY  - 2012
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2167
AB  - Properties of the fixed bed of plant material during the extraction with scCO(2) from rapeseed were investigated for the two types of mechanical pretreatments: flaking and impact milling. Obtained results indicated that particle density, bulk density of the bed and consequently the bed porosity changed during the extraction. In the case of flaked rapeseed, the change of particle diameter was also detected and quantified. On the basis of experimental data linear relationships between the particle density/bed porosity/mean particle diameter and oil content in solid were established. Mathematical model based on the mass balances for the supercritical and solid phase which took into account particle density, bed porosity and particle diameter (for flaked plant material) as variables was derived. The proposed model described experimental data with high accuracy. Possible error due to neglecting the change of the fixed bed properties was presented as well.
PB  - Elsevier Science Bv, Amsterdam
T2  - Journal of Supercritical Fluids
T1  - Fixed bed property changes during scCO(2) extraction of natural materials - Experiments and modeling
EP  - 149
SP  - 140
VL  - 72
DO  - 10.1016/j.supflu.2012.08.022
ER  - 

@article{
author = "Meyer, Florian and Stamenić, Marko and Žižović, Irena and Eggers, Rudolf",
year = "2012",
abstract = "Properties of the fixed bed of plant material during the extraction with scCO(2) from rapeseed were investigated for the two types of mechanical pretreatments: flaking and impact milling. Obtained results indicated that particle density, bulk density of the bed and consequently the bed porosity changed during the extraction. In the case of flaked rapeseed, the change of particle diameter was also detected and quantified. On the basis of experimental data linear relationships between the particle density/bed porosity/mean particle diameter and oil content in solid were established. Mathematical model based on the mass balances for the supercritical and solid phase which took into account particle density, bed porosity and particle diameter (for flaked plant material) as variables was derived. The proposed model described experimental data with high accuracy. Possible error due to neglecting the change of the fixed bed properties was presented as well.",
publisher = "Elsevier Science Bv, Amsterdam",
journal = "Journal of Supercritical Fluids",
title = "Fixed bed property changes during scCO(2) extraction of natural materials - Experiments and modeling",
pages = "149-140",
volume = "72",
doi = "10.1016/j.supflu.2012.08.022"
}

Meyer, F., Stamenić, M., Žižović, I.,& Eggers, R.. (2012). Fixed bed property changes during scCO(2) extraction of natural materials - Experiments and modeling. in Journal of Supercritical Fluids
Elsevier Science Bv, Amsterdam., 72, 140-149.
https://doi.org/10.1016/j.supflu.2012.08.022

Meyer F, Stamenić M, Žižović I, Eggers R. Fixed bed property changes during scCO(2) extraction of natural materials - Experiments and modeling. in Journal of Supercritical Fluids. 2012;72:140-149.
doi:10.1016/j.supflu.2012.08.022 .

Meyer, Florian, Stamenić, Marko, Žižović, Irena, Eggers, Rudolf, "Fixed bed property changes during scCO(2) extraction of natural materials - Experiments and modeling" in Journal of Supercritical Fluids, 72 (2012):140-149,
https://doi.org/10.1016/j.supflu.2012.08.022 . .

TY  - JOUR
AU  - Meyer, Florian
AU  - Jaeger, Philip
AU  - Eggers, Rudolf
AU  - Stamenić, Marko
AU  - Milovanović, Stoja
AU  - Žižović, Irena
PY  - 2012
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/2145
AB  - Pre-treatment of natural materials prior to their extraction strongly influences the efficiency of the process. Therefore, proper selection of pre-treatment method enables intensification of extraction process. Within this study "rapid gas decompression" (RGD) was investigated as a pretreatment method using carbon dioxide as working fluid. Oilseeds (rapeseed and sunflower seed), St. Johns Wort and Hop were studied as valuable raw materials for industrial application of supercritical fluid extraction. The sorption behaviour of carbon dioxide within the natural materials was examined gravimetrically under high pressure conditions between 5 and 26 MPa and at temperatures between 40 and 60 degrees C. It was observed that considerable amounts of carbon dioxide sorb within natural materials and a combination of dissolution within the solute phase and adsorption on the plant matrix occurs. RGD was used as a pre-treatment method prior to the extraction or as an intermediate treatment during the extraction process. The results showed that effect of RGD on extraction was the most pronounced for St. Johns Wort but also the extraction kinetics of the other materials were affected. Probable mechanisms occurring during RGD are discussed.
PB  - Elsevier Science Sa, Lausanne
T2  - Chemical Engineering and Processing-Process Intensification
T1  - Effect of CO2 pre-treatment on scCO(2) extraction of natural material
EP  - 45
SP  - 37
VL  - 56
DO  - 10.1016/j.cep.2012.02.003
ER  - 

@article{
author = "Meyer, Florian and Jaeger, Philip and Eggers, Rudolf and Stamenić, Marko and Milovanović, Stoja and Žižović, Irena",
year = "2012",
abstract = "Pre-treatment of natural materials prior to their extraction strongly influences the efficiency of the process. Therefore, proper selection of pre-treatment method enables intensification of extraction process. Within this study "rapid gas decompression" (RGD) was investigated as a pretreatment method using carbon dioxide as working fluid. Oilseeds (rapeseed and sunflower seed), St. Johns Wort and Hop were studied as valuable raw materials for industrial application of supercritical fluid extraction. The sorption behaviour of carbon dioxide within the natural materials was examined gravimetrically under high pressure conditions between 5 and 26 MPa and at temperatures between 40 and 60 degrees C. It was observed that considerable amounts of carbon dioxide sorb within natural materials and a combination of dissolution within the solute phase and adsorption on the plant matrix occurs. RGD was used as a pre-treatment method prior to the extraction or as an intermediate treatment during the extraction process. The results showed that effect of RGD on extraction was the most pronounced for St. Johns Wort but also the extraction kinetics of the other materials were affected. Probable mechanisms occurring during RGD are discussed.",
publisher = "Elsevier Science Sa, Lausanne",
journal = "Chemical Engineering and Processing-Process Intensification",
title = "Effect of CO2 pre-treatment on scCO(2) extraction of natural material",
pages = "45-37",
volume = "56",
doi = "10.1016/j.cep.2012.02.003"
}

Meyer, F., Jaeger, P., Eggers, R., Stamenić, M., Milovanović, S.,& Žižović, I.. (2012). Effect of CO2 pre-treatment on scCO(2) extraction of natural material. in Chemical Engineering and Processing-Process Intensification
Elsevier Science Sa, Lausanne., 56, 37-45.
https://doi.org/10.1016/j.cep.2012.02.003

Meyer F, Jaeger P, Eggers R, Stamenić M, Milovanović S, Žižović I. Effect of CO2 pre-treatment on scCO(2) extraction of natural material. in Chemical Engineering and Processing-Process Intensification. 2012;56:37-45.
doi:10.1016/j.cep.2012.02.003 .

Meyer, Florian, Jaeger, Philip, Eggers, Rudolf, Stamenić, Marko, Milovanović, Stoja, Žižović, Irena, "Effect of CO2 pre-treatment on scCO(2) extraction of natural material" in Chemical Engineering and Processing-Process Intensification, 56 (2012):37-45,
https://doi.org/10.1016/j.cep.2012.02.003 . .