TY  - JOUR
AU  - Jakovetić, Sonja
AU  - Luković, Nevena
AU  - Jugović, Branimir
AU  - Gvozdenović, Milica M.
AU  - Grbavčić, Sanja
AU  - Jovanović, Jelena
AU  - Knežević Jugović, Zorica
PY  - 2015
UR  - https://dais.sanu.ac.rs/123456789/3528
AB  - The objective of this research was to design an efficient continuously operated membrane reactor with a separation unit for egg white protein (EWP) hydrolysis and production of hydrolysates with improved antioxidant properties. For this purpose, a mechanically stirred tank reactor coupled with the polyethersulfone ultrafiltration module with a molecular weight cutoff of 10 kDa was employed. Several proteolytic enzymes have been tested in order to obtain the best quality of peptide-based formulations intended for human consumption. Among protease from Bacillus licheniformis (Alcalase), protease from Bacillus amyloliquefaciens (Neutrase), and protease from papaya latex (papain), the highest degree of hydrolysis (DH), as well as the best antioxidant properties of obtained hydrolysates, was achieved with Alcalase. The effects of operating variables such as enzyme/substrate ([E]/[S]) ratio, impeller speed, and permeate flow rate were further studied using response surface methodology (RSM) and Box–Behnken experimental design. Results obtained in RSM analysis confirmed that over the studied range [E]/[S] ratio, impeller speed and permeate flow rate had the significant effect on the DH and reactor capacity. The effects of different impeller geometries were also studied and four-bladed propeller stirrer enabled the highest DH. Antioxidant properties were analyzed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH), by the 2,2′-azino-bis-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) radical scavenging activity, and by the linear voltammetry methods. Results show that the use of Alcalase in the membrane reactor system is of potential interest for the EWP hydrolysis and obtaining value-added egg products. © 2014, Springer Science+Business Media New York.
PB  - Springer
T2  - Food and Bioprocess Technology
T1  - Production of Antioxidant Egg White Hydrolysates in a Continuous Stirred Tank Enzyme Reactor Coupled with Membrane Separation Unit
SP  - 287
EP  - 300
VL  - 8
IS  - 2
DO  - 10.1007/s11947-014-1402-y
UR  - https://hdl.handle.net/21.15107/rcub_dais_3528
ER  - 

@article{
author = "Jakovetić, Sonja and Luković, Nevena and Jugović, Branimir and Gvozdenović, Milica M. and Grbavčić, Sanja and Jovanović, Jelena and Knežević Jugović, Zorica",
year = "2015",
abstract = "The objective of this research was to design an efficient continuously operated membrane reactor with a separation unit for egg white protein (EWP) hydrolysis and production of hydrolysates with improved antioxidant properties. For this purpose, a mechanically stirred tank reactor coupled with the polyethersulfone ultrafiltration module with a molecular weight cutoff of 10 kDa was employed. Several proteolytic enzymes have been tested in order to obtain the best quality of peptide-based formulations intended for human consumption. Among protease from Bacillus licheniformis (Alcalase), protease from Bacillus amyloliquefaciens (Neutrase), and protease from papaya latex (papain), the highest degree of hydrolysis (DH), as well as the best antioxidant properties of obtained hydrolysates, was achieved with Alcalase. The effects of operating variables such as enzyme/substrate ([E]/[S]) ratio, impeller speed, and permeate flow rate were further studied using response surface methodology (RSM) and Box–Behnken experimental design. Results obtained in RSM analysis confirmed that over the studied range [E]/[S] ratio, impeller speed and permeate flow rate had the significant effect on the DH and reactor capacity. The effects of different impeller geometries were also studied and four-bladed propeller stirrer enabled the highest DH. Antioxidant properties were analyzed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH), by the 2,2′-azino-bis-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) radical scavenging activity, and by the linear voltammetry methods. Results show that the use of Alcalase in the membrane reactor system is of potential interest for the EWP hydrolysis and obtaining value-added egg products. © 2014, Springer Science+Business Media New York.",
publisher = "Springer",
journal = "Food and Bioprocess Technology",
title = "Production of Antioxidant Egg White Hydrolysates in a Continuous Stirred Tank Enzyme Reactor Coupled with Membrane Separation Unit",
pages = "287-300",
volume = "8",
number = "2",
doi = "10.1007/s11947-014-1402-y",
url = "https://hdl.handle.net/21.15107/rcub_dais_3528"
}

Jakovetić, S., Luković, N., Jugović, B., Gvozdenović, M. M., Grbavčić, S., Jovanović, J.,& Knežević Jugović, Z.. (2015). Production of Antioxidant Egg White Hydrolysates in a Continuous Stirred Tank Enzyme Reactor Coupled with Membrane Separation Unit. in Food and Bioprocess Technology
Springer., 8(2), 287-300.
https://doi.org/10.1007/s11947-014-1402-y
https://hdl.handle.net/21.15107/rcub_dais_3528

Jakovetić S, Luković N, Jugović B, Gvozdenović MM, Grbavčić S, Jovanović J, Knežević Jugović Z. Production of Antioxidant Egg White Hydrolysates in a Continuous Stirred Tank Enzyme Reactor Coupled with Membrane Separation Unit. in Food and Bioprocess Technology. 2015;8(2):287-300.
doi:10.1007/s11947-014-1402-y
https://hdl.handle.net/21.15107/rcub_dais_3528 .

Jakovetić, Sonja, Luković, Nevena, Jugović, Branimir, Gvozdenović, Milica M., Grbavčić, Sanja, Jovanović, Jelena, Knežević Jugović, Zorica, "Production of Antioxidant Egg White Hydrolysates in a Continuous Stirred Tank Enzyme Reactor Coupled with Membrane Separation Unit" in Food and Bioprocess Technology, 8, no. 2 (2015):287-300,
https://doi.org/10.1007/s11947-014-1402-y .,
https://hdl.handle.net/21.15107/rcub_dais_3528 .

TY  - JOUR
AU  - Jakovetić, Sonja
AU  - Jugović, Branimir
AU  - Gvozdenović, Milica M.
AU  - Bezbradica, Dejan
AU  - Antov, Mirjana
AU  - Mijin, Dušan
AU  - Knežević Jugović, Zorica
PY  - 2013
UR  - https://dais.sanu.ac.rs/123456789/355
AB  - Immobilized lipase from Candida antarctica (Novozyme 435) was tested for the synthesis of various phenolic acid esters (ethyl and n-butyl cinnamate, ethyl p-coumarate and n-butyl p-methoxycinnamate). The second-order kinetic model was used to mathematically describe the reaction kinetics and to compare present processes quantitatively. It was found that the model agreed well with the experimental data. Further, the effect of alcohol type on the esterification of cinnamic acid was investigated. The immobilized lipase showed more ability to catalyze the synthesis of butyl cinnamate. Therefore, the process was optimized for the synthesis of butyl cinnamate as a function of solvent polarity (logP) and amount of biocatalyst. The highest ester yield of 60.7 % was obtained for the highest enzyme concentration tested (3 % w/w), but the productivity was for 34 % lower than the corresponding value obtained for the enzyme concentration of 1 % (w/w). The synthesized esters were purified, identified, and screened for antioxidant activities. Both DPPH assay and cyclic voltammetry measurement have shown that cinnamic acid esters have better antioxidant properties than cinnamic acid itself.
PB  - Springer
T2  - Applied Biochemistry and Biotechnology
T1  - Synthesis of Aliphatic Esters of Cinnamic Acid as Potential Lipophilic Antioxidants Catalyzed by Lipase B from Candida antarctica
SP  - 1560
EP  - 1573
VL  - 170
IS  - 7
DO  - 10.1007/s12010-013-0294-z
UR  - https://hdl.handle.net/21.15107/rcub_dais_355
ER  - 

@article{
author = "Jakovetić, Sonja and Jugović, Branimir and Gvozdenović, Milica M. and Bezbradica, Dejan and Antov, Mirjana and Mijin, Dušan and Knežević Jugović, Zorica",
year = "2013",
abstract = "Immobilized lipase from Candida antarctica (Novozyme 435) was tested for the synthesis of various phenolic acid esters (ethyl and n-butyl cinnamate, ethyl p-coumarate and n-butyl p-methoxycinnamate). The second-order kinetic model was used to mathematically describe the reaction kinetics and to compare present processes quantitatively. It was found that the model agreed well with the experimental data. Further, the effect of alcohol type on the esterification of cinnamic acid was investigated. The immobilized lipase showed more ability to catalyze the synthesis of butyl cinnamate. Therefore, the process was optimized for the synthesis of butyl cinnamate as a function of solvent polarity (logP) and amount of biocatalyst. The highest ester yield of 60.7 % was obtained for the highest enzyme concentration tested (3 % w/w), but the productivity was for 34 % lower than the corresponding value obtained for the enzyme concentration of 1 % (w/w). The synthesized esters were purified, identified, and screened for antioxidant activities. Both DPPH assay and cyclic voltammetry measurement have shown that cinnamic acid esters have better antioxidant properties than cinnamic acid itself.",
publisher = "Springer",
journal = "Applied Biochemistry and Biotechnology",
title = "Synthesis of Aliphatic Esters of Cinnamic Acid as Potential Lipophilic Antioxidants Catalyzed by Lipase B from Candida antarctica",
pages = "1560-1573",
volume = "170",
number = "7",
doi = "10.1007/s12010-013-0294-z",
url = "https://hdl.handle.net/21.15107/rcub_dais_355"
}

Jakovetić, S., Jugović, B., Gvozdenović, M. M., Bezbradica, D., Antov, M., Mijin, D.,& Knežević Jugović, Z.. (2013). Synthesis of Aliphatic Esters of Cinnamic Acid as Potential Lipophilic Antioxidants Catalyzed by Lipase B from Candida antarctica. in Applied Biochemistry and Biotechnology
Springer., 170(7), 1560-1573.
https://doi.org/10.1007/s12010-013-0294-z
https://hdl.handle.net/21.15107/rcub_dais_355

Jakovetić S, Jugović B, Gvozdenović MM, Bezbradica D, Antov M, Mijin D, Knežević Jugović Z. Synthesis of Aliphatic Esters of Cinnamic Acid as Potential Lipophilic Antioxidants Catalyzed by Lipase B from Candida antarctica. in Applied Biochemistry and Biotechnology. 2013;170(7):1560-1573.
doi:10.1007/s12010-013-0294-z
https://hdl.handle.net/21.15107/rcub_dais_355 .

Jakovetić, Sonja, Jugović, Branimir, Gvozdenović, Milica M., Bezbradica, Dejan, Antov, Mirjana, Mijin, Dušan, Knežević Jugović, Zorica, "Synthesis of Aliphatic Esters of Cinnamic Acid as Potential Lipophilic Antioxidants Catalyzed by Lipase B from Candida antarctica" in Applied Biochemistry and Biotechnology, 170, no. 7 (2013):1560-1573,
https://doi.org/10.1007/s12010-013-0294-z .,
https://hdl.handle.net/21.15107/rcub_dais_355 .

TY  - CONF
AU  - Knežević Jugović, Zorica
AU  - Jakovetić, Sonja
AU  - Jugović, Branimir
AU  - Gvozdenović, Milica M.
AU  - Grbavčić, Sanja
AU  - Bezbradica, Dejan
AU  - Antov, Mirjana
PY  - 2012
UR  - https://dais.sanu.ac.rs/123456789/493
AB  - The esterification activity of the commercial immobilized lipase CALB towards cinnamic acids and its derivative has been studied. Using cinnamic acid as substrate, the reaction rate constants (1.95 h-1 mM-1 for ethanol and 3.07 h-1 mM-1 for butanol) were more than four and nine times higher compared to those obtained with p-coumaric (0.47 h-1 mM-1) and p-methoxycinnamic acids (0.32 h-1 mM-1), respectively. Thus, esterification of cinnamic acid with ethanol by using C. antarctica lipase has selected as a model reaction for further study. Isooctane is shown to be the best solvent for this reaction even though solubility of cinnamic acid in this a polar solvent is very low. Highest esterification yield of ethyl cinnamate is obtained when initial molar ratio of substrates 1:3 (cinnamic acid is limiting substrate) is used. Esterification of cinnamic acid appeared to result in increasing radical-scavenging ability. The effect of esterification of cinnamic acid was also confirmed by electrochemical method using ethyl cinnamate which appeared to enhance the antioxidant activity. These findings should stimulate the application of such lipase-catalyzed reactions for the preparation of food acceptable esters of cinnamic acid as potential lipophilic antioxidants.
PB  - Tatranské Matliare : Slovak Society of Chemical Engineering
C3  - Proceedings of the 39th International Conference of Slovak Society of Chemical Engineering
T1  - Enzymatic Synthesis of Aliphatic Esters of Phenolic Acids and Evaluation of Their Antioxidant Properties
SP  - 1426
EP  - 1432
UR  - https://hdl.handle.net/21.15107/rcub_dais_493
ER  - 

@conference{
author = "Knežević Jugović, Zorica and Jakovetić, Sonja and Jugović, Branimir and Gvozdenović, Milica M. and Grbavčić, Sanja and Bezbradica, Dejan and Antov, Mirjana",
year = "2012",
abstract = "The esterification activity of the commercial immobilized lipase CALB towards cinnamic acids and its derivative has been studied. Using cinnamic acid as substrate, the reaction rate constants (1.95 h-1 mM-1 for ethanol and 3.07 h-1 mM-1 for butanol) were more than four and nine times higher compared to those obtained with p-coumaric (0.47 h-1 mM-1) and p-methoxycinnamic acids (0.32 h-1 mM-1), respectively. Thus, esterification of cinnamic acid with ethanol by using C. antarctica lipase has selected as a model reaction for further study. Isooctane is shown to be the best solvent for this reaction even though solubility of cinnamic acid in this a polar solvent is very low. Highest esterification yield of ethyl cinnamate is obtained when initial molar ratio of substrates 1:3 (cinnamic acid is limiting substrate) is used. Esterification of cinnamic acid appeared to result in increasing radical-scavenging ability. The effect of esterification of cinnamic acid was also confirmed by electrochemical method using ethyl cinnamate which appeared to enhance the antioxidant activity. These findings should stimulate the application of such lipase-catalyzed reactions for the preparation of food acceptable esters of cinnamic acid as potential lipophilic antioxidants.",
publisher = "Tatranské Matliare : Slovak Society of Chemical Engineering",
journal = "Proceedings of the 39th International Conference of Slovak Society of Chemical Engineering",
title = "Enzymatic Synthesis of Aliphatic Esters of Phenolic Acids and Evaluation of Their Antioxidant Properties",
pages = "1426-1432",
url = "https://hdl.handle.net/21.15107/rcub_dais_493"
}

Knežević Jugović, Z., Jakovetić, S., Jugović, B., Gvozdenović, M. M., Grbavčić, S., Bezbradica, D.,& Antov, M.. (2012). Enzymatic Synthesis of Aliphatic Esters of Phenolic Acids and Evaluation of Their Antioxidant Properties. in Proceedings of the 39th International Conference of Slovak Society of Chemical Engineering
Tatranské Matliare : Slovak Society of Chemical Engineering., 1426-1432.
https://hdl.handle.net/21.15107/rcub_dais_493

Knežević Jugović Z, Jakovetić S, Jugović B, Gvozdenović MM, Grbavčić S, Bezbradica D, Antov M. Enzymatic Synthesis of Aliphatic Esters of Phenolic Acids and Evaluation of Their Antioxidant Properties. in Proceedings of the 39th International Conference of Slovak Society of Chemical Engineering. 2012;:1426-1432.
https://hdl.handle.net/21.15107/rcub_dais_493 .

Knežević Jugović, Zorica, Jakovetić, Sonja, Jugović, Branimir, Gvozdenović, Milica M., Grbavčić, Sanja, Bezbradica, Dejan, Antov, Mirjana, "Enzymatic Synthesis of Aliphatic Esters of Phenolic Acids and Evaluation of Their Antioxidant Properties" in Proceedings of the 39th International Conference of Slovak Society of Chemical Engineering (2012):1426-1432,
https://hdl.handle.net/21.15107/rcub_dais_493 .

TY  - CONF
AU  - Knežević Jugović, Zorica
AU  - Jugović, Branimir
AU  - Jakovetić, Sonja
AU  - Bezbradica, Dejan
AU  - Antov, Mirjana
AU  - Saied, Omar Ali
AU  - Gvozdenović, Milica M.
PY  - 2011
UR  - https://dais.sanu.ac.rs/123456789/549
AB  - The present study compares the results of two different methods employed for preparation of polyaniline based glucose biosensor with respect to enzyme loading, biosensing efficiency and potential stability. Kinetic analysis of the potentiometric data for two enzyme immobilized electrode systems show that the GOx/PANI electrode is suitable for assaying samples with low analyte concentrations, whereas the GOx/m-ABA/PANI electrode system exhibits a better potential stability. It may therefore be possible to achieve high level of biosensing efficiency by chemical modeling and synthesis combined with careful selection of the immobilization method.
PB  - Tatranské Matliare : Slovak Society of Chemical Engineering
C3  - Proceedings of the 38th International Conference of Slovak Society of Chemical Engineering
T1  - Design of a polyaniline based biosensor electrode for glucose: A comparative study of two immobilized systems
SP  - 1519
EP  - 1525
UR  - https://hdl.handle.net/21.15107/rcub_dais_549
ER  - 

@conference{
author = "Knežević Jugović, Zorica and Jugović, Branimir and Jakovetić, Sonja and Bezbradica, Dejan and Antov, Mirjana and Saied, Omar Ali and Gvozdenović, Milica M.",
year = "2011",
abstract = "The present study compares the results of two different methods employed for preparation of polyaniline based glucose biosensor with respect to enzyme loading, biosensing efficiency and potential stability. Kinetic analysis of the potentiometric data for two enzyme immobilized electrode systems show that the GOx/PANI electrode is suitable for assaying samples with low analyte concentrations, whereas the GOx/m-ABA/PANI electrode system exhibits a better potential stability. It may therefore be possible to achieve high level of biosensing efficiency by chemical modeling and synthesis combined with careful selection of the immobilization method.",
publisher = "Tatranské Matliare : Slovak Society of Chemical Engineering",
journal = "Proceedings of the 38th International Conference of Slovak Society of Chemical Engineering",
title = "Design of a polyaniline based biosensor electrode for glucose: A comparative study of two immobilized systems",
pages = "1519-1525",
url = "https://hdl.handle.net/21.15107/rcub_dais_549"
}

Knežević Jugović, Z., Jugović, B., Jakovetić, S., Bezbradica, D., Antov, M., Saied, O. A.,& Gvozdenović, M. M.. (2011). Design of a polyaniline based biosensor electrode for glucose: A comparative study of two immobilized systems. in Proceedings of the 38th International Conference of Slovak Society of Chemical Engineering
Tatranské Matliare : Slovak Society of Chemical Engineering., 1519-1525.
https://hdl.handle.net/21.15107/rcub_dais_549

Knežević Jugović Z, Jugović B, Jakovetić S, Bezbradica D, Antov M, Saied OA, Gvozdenović MM. Design of a polyaniline based biosensor electrode for glucose: A comparative study of two immobilized systems. in Proceedings of the 38th International Conference of Slovak Society of Chemical Engineering. 2011;:1519-1525.
https://hdl.handle.net/21.15107/rcub_dais_549 .

Knežević Jugović, Zorica, Jugović, Branimir, Jakovetić, Sonja, Bezbradica, Dejan, Antov, Mirjana, Saied, Omar Ali, Gvozdenović, Milica M., "Design of a polyaniline based biosensor electrode for glucose: A comparative study of two immobilized systems" in Proceedings of the 38th International Conference of Slovak Society of Chemical Engineering (2011):1519-1525,
https://hdl.handle.net/21.15107/rcub_dais_549 .

TY  - JOUR
AU  - Bezbradica, Dejan
AU  - Jugović, Branimir
AU  - Gvozdenović, Milica M.
AU  - Jakovetić, Sonja
AU  - Knežević Jugović, Zorica
PY  - 2011
UR  - https://dais.sanu.ac.rs/123456789/702
AB  - Electrochemical synthesis of polyaniline support for enzyme immobilization provides easier control over the properties of obtained polymer and reduced risk of biocatalyst inactivation with residues of toxic compounds. In the present study, immobilization of lipase from Candida rugosa on electrochemically synthesized PANI (activated with glutaraldehyde) resulted with high lipase loadings up to 93.7 mg of proteins per gram of dry support. The activation of support and immobilization were optimized, with respect to activity yield. The optimum concentration of glutaraldehyde was 2% (w/v) and optimum concentration of enzyme was 4 mg ml−1. Modification of enzyme surface with carbodiimide and ethylenediamine was performed in order to increase concentration of amino groups. Aminated lipase exhibited higher specific activity (52%) and thermal stability (3 times) after immobilization, compared with non-modified lipase. Also, reusability of immobilized enzyme was significantly increased with amination, especially if immobilization was performed at pH 10, so in such a way obtained derivative retained 91% of activity after 15 reaction cycles.
PB  - Elsevier
T2  - Journal of Molecular Catalysis B: Enzymatic
T1  - Electrochemically synthesized polyaniline as support for lipase immobilization
SP  - 55
EP  - 60
DO  - 10.1016/j.molcatb.2011.02.004
UR  - https://hdl.handle.net/21.15107/rcub_dais_702
ER  - 

@article{
author = "Bezbradica, Dejan and Jugović, Branimir and Gvozdenović, Milica M. and Jakovetić, Sonja and Knežević Jugović, Zorica",
year = "2011",
abstract = "Electrochemical synthesis of polyaniline support for enzyme immobilization provides easier control over the properties of obtained polymer and reduced risk of biocatalyst inactivation with residues of toxic compounds. In the present study, immobilization of lipase from Candida rugosa on electrochemically synthesized PANI (activated with glutaraldehyde) resulted with high lipase loadings up to 93.7 mg of proteins per gram of dry support. The activation of support and immobilization were optimized, with respect to activity yield. The optimum concentration of glutaraldehyde was 2% (w/v) and optimum concentration of enzyme was 4 mg ml−1. Modification of enzyme surface with carbodiimide and ethylenediamine was performed in order to increase concentration of amino groups. Aminated lipase exhibited higher specific activity (52%) and thermal stability (3 times) after immobilization, compared with non-modified lipase. Also, reusability of immobilized enzyme was significantly increased with amination, especially if immobilization was performed at pH 10, so in such a way obtained derivative retained 91% of activity after 15 reaction cycles.",
publisher = "Elsevier",
journal = "Journal of Molecular Catalysis B: Enzymatic",
title = "Electrochemically synthesized polyaniline as support for lipase immobilization",
pages = "55-60",
doi = "10.1016/j.molcatb.2011.02.004",
url = "https://hdl.handle.net/21.15107/rcub_dais_702"
}

Bezbradica, D., Jugović, B., Gvozdenović, M. M., Jakovetić, S.,& Knežević Jugović, Z.. (2011). Electrochemically synthesized polyaniline as support for lipase immobilization. in Journal of Molecular Catalysis B: Enzymatic
Elsevier., 55-60.
https://doi.org/10.1016/j.molcatb.2011.02.004
https://hdl.handle.net/21.15107/rcub_dais_702

Bezbradica D, Jugović B, Gvozdenović MM, Jakovetić S, Knežević Jugović Z. Electrochemically synthesized polyaniline as support for lipase immobilization. in Journal of Molecular Catalysis B: Enzymatic. 2011;:55-60.
doi:10.1016/j.molcatb.2011.02.004
https://hdl.handle.net/21.15107/rcub_dais_702 .

Bezbradica, Dejan, Jugović, Branimir, Gvozdenović, Milica M., Jakovetić, Sonja, Knežević Jugović, Zorica, "Electrochemically synthesized polyaniline as support for lipase immobilization" in Journal of Molecular Catalysis B: Enzymatic (2011):55-60,
https://doi.org/10.1016/j.molcatb.2011.02.004 .,
https://hdl.handle.net/21.15107/rcub_dais_702 .