TY  - CONF
AU  - Jovanović, Jelena
AU  - Stefanović, Andrea
AU  - Šekuljica, Nataša
AU  - Grbavčić, Sanja
AU  - Jakovetić Tanasković, Sonja
AU  - Bugarski, Branko
AU  - Knežević-Jugović, Zorica
PY  - 2016
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6267
AB  - The main purpose of this research was to investigate the effect of high-intensity ultrasound treatment on one-step proteolysis of egg white proteins (EWPs) using commercial food-grade protease Alcalase as well as evaluating antioxidant and antibacterial capacity of sonicated hydrolysates rich in bioactive peptides. Prior to the Alcalase proteolysis, a series of 10 % (w/w) egg white (EW) solution samples were exposed to ultrasonic waves in ultrasonic water bath with a frequency of 40 kHz during 15 min and ultrasound probe high-intensity with a frequency 20 kHz during 15 min. The sonicated EWP solutions were intensively hydrolysed by the addition the bacterial endopeptidase from Bacillus licheniformis, namely Alcalase in the amount of 2 % (w/w). The proteolysis was performed in a glass batch reactor with mechanical stirring at 240 rpm at optimum condition for Alcalase (50 °C and pH 8.0). Upon completion of the hydrolysis, the reaction mixture was cooled down to room temperature and centrifuged at 12,000×g for 10 min. The bioactive hydrolysate was finally collected by decantation and stored at 4 °C. The antioxidant capacity of bioactive hydrolysates was evaluated by measurements the oxidation of β-carotene linoleic acid emulsion and scavenging of hydroxyl radicals. The antibacterial capacity was estimated against Gram-positive bacteria (Staphylococcus aureus ATCC 25923) and Gram-negative bacteria (Escherichia coli ATCC 25922) by hydrolysates' susceptibility of agar diffusion. The hydrolysate derived by proteolysis-assited ultrasound probe (UPH) has shown to be most effective in oxidation of β-carotene linoleic acid emulsion compared to hydrolysate acquired by proteolysis-assited ultrasound bath (UBH). The values of inhibition of lipid peroxidation were 85.4±0.42 and 73.9±0.49% for UPH and UBH respectively. The both hydrolysates were found to be potent scavengers of hydroxyl radicals compared to the untreated EW and its hydrolysate. Namely, UPH and UBH hydroxyl radical scavenging activities were 61.6±0.18 and 62.3±0.22 %, respectively. The results acquired from this research pointed that EWP hydrolysates have an intense inhibitory activity on Gram-positive bacteria, poor on Gram-negative bacteria, especially UPH. The inhibition zone both sonicated hydrolysates were significantly greater that control. Minimal inhibitor concentration against S. aureus and E. coli of UPH was significantly higher than UBH (63.3±0.83 μg/mL and 79.1±1.04 μg/mL, respectively). This research emphasized that by proteolysis-assisted high intensity ultrasound treatment, received hydrolysate with improved antimicrobial and antioxidant activities can be promoted enhancing utilization of EWPs as bioactive component of dietary supplements. Likewise, the results have been indicated that the
producing bioactive hydrolysates from intact EWPs were affected by the ultrasound treatment type.
PB  - Portugal : Proteomass
C3  - Book of Abstracts / 2nd International Conference on Ultrasonic-based Applications: from analysis to synthesis ULTRASONICS
T1  - Antibacterial and antioxidant capacity of egg white hydrolysates screened from proteolysis-­assisted high intensity ultrasound treatment
EP  - 67
SP  - 66
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6267
ER  - 

@conference{
author = "Jovanović, Jelena and Stefanović, Andrea and Šekuljica, Nataša and Grbavčić, Sanja and Jakovetić Tanasković, Sonja and Bugarski, Branko and Knežević-Jugović, Zorica",
year = "2016",
abstract = "The main purpose of this research was to investigate the effect of high-intensity ultrasound treatment on one-step proteolysis of egg white proteins (EWPs) using commercial food-grade protease Alcalase as well as evaluating antioxidant and antibacterial capacity of sonicated hydrolysates rich in bioactive peptides. Prior to the Alcalase proteolysis, a series of 10 % (w/w) egg white (EW) solution samples were exposed to ultrasonic waves in ultrasonic water bath with a frequency of 40 kHz during 15 min and ultrasound probe high-intensity with a frequency 20 kHz during 15 min. The sonicated EWP solutions were intensively hydrolysed by the addition the bacterial endopeptidase from Bacillus licheniformis, namely Alcalase in the amount of 2 % (w/w). The proteolysis was performed in a glass batch reactor with mechanical stirring at 240 rpm at optimum condition for Alcalase (50 °C and pH 8.0). Upon completion of the hydrolysis, the reaction mixture was cooled down to room temperature and centrifuged at 12,000×g for 10 min. The bioactive hydrolysate was finally collected by decantation and stored at 4 °C. The antioxidant capacity of bioactive hydrolysates was evaluated by measurements the oxidation of β-carotene linoleic acid emulsion and scavenging of hydroxyl radicals. The antibacterial capacity was estimated against Gram-positive bacteria (Staphylococcus aureus ATCC 25923) and Gram-negative bacteria (Escherichia coli ATCC 25922) by hydrolysates' susceptibility of agar diffusion. The hydrolysate derived by proteolysis-assited ultrasound probe (UPH) has shown to be most effective in oxidation of β-carotene linoleic acid emulsion compared to hydrolysate acquired by proteolysis-assited ultrasound bath (UBH). The values of inhibition of lipid peroxidation were 85.4±0.42 and 73.9±0.49% for UPH and UBH respectively. The both hydrolysates were found to be potent scavengers of hydroxyl radicals compared to the untreated EW and its hydrolysate. Namely, UPH and UBH hydroxyl radical scavenging activities were 61.6±0.18 and 62.3±0.22 %, respectively. The results acquired from this research pointed that EWP hydrolysates have an intense inhibitory activity on Gram-positive bacteria, poor on Gram-negative bacteria, especially UPH. The inhibition zone both sonicated hydrolysates were significantly greater that control. Minimal inhibitor concentration against S. aureus and E. coli of UPH was significantly higher than UBH (63.3±0.83 μg/mL and 79.1±1.04 μg/mL, respectively). This research emphasized that by proteolysis-assisted high intensity ultrasound treatment, received hydrolysate with improved antimicrobial and antioxidant activities can be promoted enhancing utilization of EWPs as bioactive component of dietary supplements. Likewise, the results have been indicated that the
producing bioactive hydrolysates from intact EWPs were affected by the ultrasound treatment type.",
publisher = "Portugal : Proteomass",
journal = "Book of Abstracts / 2nd International Conference on Ultrasonic-based Applications: from analysis to synthesis ULTRASONICS",
title = "Antibacterial and antioxidant capacity of egg white hydrolysates screened from proteolysis-­assisted high intensity ultrasound treatment",
pages = "67-66",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6267"
}

Jovanović, J., Stefanović, A., Šekuljica, N., Grbavčić, S., Jakovetić Tanasković, S., Bugarski, B.,& Knežević-Jugović, Z.. (2016). Antibacterial and antioxidant capacity of egg white hydrolysates screened from proteolysis-­assisted high intensity ultrasound treatment. in Book of Abstracts / 2nd International Conference on Ultrasonic-based Applications: from analysis to synthesis ULTRASONICS
Portugal : Proteomass., 66-67.
https://hdl.handle.net/21.15107/rcub_technorep_6267

Jovanović J, Stefanović A, Šekuljica N, Grbavčić S, Jakovetić Tanasković S, Bugarski B, Knežević-Jugović Z. Antibacterial and antioxidant capacity of egg white hydrolysates screened from proteolysis-­assisted high intensity ultrasound treatment. in Book of Abstracts / 2nd International Conference on Ultrasonic-based Applications: from analysis to synthesis ULTRASONICS. 2016;:66-67.
https://hdl.handle.net/21.15107/rcub_technorep_6267 .

Jovanović, Jelena, Stefanović, Andrea, Šekuljica, Nataša, Grbavčić, Sanja, Jakovetić Tanasković, Sonja, Bugarski, Branko, Knežević-Jugović, Zorica, "Antibacterial and antioxidant capacity of egg white hydrolysates screened from proteolysis-­assisted high intensity ultrasound treatment" in Book of Abstracts / 2nd International Conference on Ultrasonic-based Applications: from analysis to synthesis ULTRASONICS (2016):66-67,
https://hdl.handle.net/21.15107/rcub_technorep_6267 .

TY  - CONF
AU  - Stefanović, Andrea
AU  - Jovanović, Jelena
AU  - Šekuljica, Nataša
AU  - Grbavčić, Sanja
AU  - Luković, Nevena
AU  - Bugarski, Branko
AU  - Knežević-Jugović, Zorica
PY  - 2016
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6268
AB  - The main objective of this research is to quantitatively investigate the impact of high intensity
ultrasound waves generated by probe-type sonicator on the selected functional and structural properties of papainassisted egg white protein hydolysis (PEWPHs). As well, the effect of pretreatment time on the susceptibility to proteolysis was investigated. 10 % (w/w) aqueous solution of egg white proteins (EWPs) was sonicated at an actual ultrasonic power of 30.7 W. The trials have been accomplished using the modified vibratory cavitation test set up source at resonant frequency of 20 ± 0.2 kHz during the different pretreatment time (2, 5, 10, 15 and 20 minutes). The functional properties of the PEWPHs were probed in terms of solubility, digestibility and foaming ability. In order to understand the molecular structure and morphology of ultrasound pretreated EWPs, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and scanning electron microscopy (SEM) were employed to image the materials. The performance of ultrasound PEWPHs were compared to their untreated counterparts. The proteolytic pattern of papain-assisted EWP hydrolysis was significantly improved for all pretreatment time applied, but the prolonged exposure to ultrasound of 20 min seemed to have a negative effect on the EWPs hydrolysis. The treatment of the EWPs during 5 min can be adopted as the optimal for PEWPHs.
Ultrasound pretreatment seemed to increase solubility and digestibility and also caused enhanced foaming properties of PEWPHs compared to the control (untreated EWPs). It was found that particle morphology (SEM images) of PEWPHs were completely different and the less small particles were trapped in large dents of large particles and narrow range of particle size was observed for ultrasound pretreated PEWPHs. SDS-PAGE patterns affected on the release some small peptides (< 14.4 kDa) causing a significant decrease in molecular weight of ultrasound pretreated PEWPHs. The outcomes presented here suggest that the application of the probe-type sonicator have na important role in the improvement of functional and structural properties of PEWPHs and the combined ultrasound pretreatment and enzymatic hydrolysis, not only represents a rapid, efficient and reliable alternative to improve the quality of EWPs, but it also has the potential to develop new products with a unique functionality.
PB  - Portugal : Proteomass
C3  - Book of Abstracts / 2nd International Conference on Ultrasonic-­based Applications: from analysis to synthesis ULTRASONICS
T1  - Structural and functional characterization of papain-assisted ultrasound pretreated egg white hydrolysis
EP  - 45
SP  - 44
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6268
ER  - 

@conference{
author = "Stefanović, Andrea and Jovanović, Jelena and Šekuljica, Nataša and Grbavčić, Sanja and Luković, Nevena and Bugarski, Branko and Knežević-Jugović, Zorica",
year = "2016",
abstract = "The main objective of this research is to quantitatively investigate the impact of high intensity
ultrasound waves generated by probe-type sonicator on the selected functional and structural properties of papainassisted egg white protein hydolysis (PEWPHs). As well, the effect of pretreatment time on the susceptibility to proteolysis was investigated. 10 % (w/w) aqueous solution of egg white proteins (EWPs) was sonicated at an actual ultrasonic power of 30.7 W. The trials have been accomplished using the modified vibratory cavitation test set up source at resonant frequency of 20 ± 0.2 kHz during the different pretreatment time (2, 5, 10, 15 and 20 minutes). The functional properties of the PEWPHs were probed in terms of solubility, digestibility and foaming ability. In order to understand the molecular structure and morphology of ultrasound pretreated EWPs, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and scanning electron microscopy (SEM) were employed to image the materials. The performance of ultrasound PEWPHs were compared to their untreated counterparts. The proteolytic pattern of papain-assisted EWP hydrolysis was significantly improved for all pretreatment time applied, but the prolonged exposure to ultrasound of 20 min seemed to have a negative effect on the EWPs hydrolysis. The treatment of the EWPs during 5 min can be adopted as the optimal for PEWPHs.
Ultrasound pretreatment seemed to increase solubility and digestibility and also caused enhanced foaming properties of PEWPHs compared to the control (untreated EWPs). It was found that particle morphology (SEM images) of PEWPHs were completely different and the less small particles were trapped in large dents of large particles and narrow range of particle size was observed for ultrasound pretreated PEWPHs. SDS-PAGE patterns affected on the release some small peptides (< 14.4 kDa) causing a significant decrease in molecular weight of ultrasound pretreated PEWPHs. The outcomes presented here suggest that the application of the probe-type sonicator have na important role in the improvement of functional and structural properties of PEWPHs and the combined ultrasound pretreatment and enzymatic hydrolysis, not only represents a rapid, efficient and reliable alternative to improve the quality of EWPs, but it also has the potential to develop new products with a unique functionality.",
publisher = "Portugal : Proteomass",
journal = "Book of Abstracts / 2nd International Conference on Ultrasonic-­based Applications: from analysis to synthesis ULTRASONICS",
title = "Structural and functional characterization of papain-assisted ultrasound pretreated egg white hydrolysis",
pages = "45-44",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6268"
}

Stefanović, A., Jovanović, J., Šekuljica, N., Grbavčić, S., Luković, N., Bugarski, B.,& Knežević-Jugović, Z.. (2016). Structural and functional characterization of papain-assisted ultrasound pretreated egg white hydrolysis. in Book of Abstracts / 2nd International Conference on Ultrasonic-­based Applications: from analysis to synthesis ULTRASONICS
Portugal : Proteomass., 44-45.
https://hdl.handle.net/21.15107/rcub_technorep_6268

Stefanović A, Jovanović J, Šekuljica N, Grbavčić S, Luković N, Bugarski B, Knežević-Jugović Z. Structural and functional characterization of papain-assisted ultrasound pretreated egg white hydrolysis. in Book of Abstracts / 2nd International Conference on Ultrasonic-­based Applications: from analysis to synthesis ULTRASONICS. 2016;:44-45.
https://hdl.handle.net/21.15107/rcub_technorep_6268 .

Stefanović, Andrea, Jovanović, Jelena, Šekuljica, Nataša, Grbavčić, Sanja, Luković, Nevena, Bugarski, Branko, Knežević-Jugović, Zorica, "Structural and functional characterization of papain-assisted ultrasound pretreated egg white hydrolysis" in Book of Abstracts / 2nd International Conference on Ultrasonic-­based Applications: from analysis to synthesis ULTRASONICS (2016):44-45,
https://hdl.handle.net/21.15107/rcub_technorep_6268 .

TY  - CONF
AU  - Knežević-Jugović, Zorica
AU  - Jovanović, Jelena
AU  - Stefanović, Andrea
AU  - Žuža, Milena
AU  - Šekuljica, Nataša
AU  - Manojlović, Verica
AU  - Bugarski, Branko
PY  - 2015
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6263
AB  - The objective of this research was a production of egg white protein hydrolysates with improved antioxidant properties. For this purpose, a thermal and ultrasound pretreated egg white proteins were intensively hydrolysed with a commercial food-grade bacterial protease Alcalase. Thus obtained hydrolysates were further separated by sequential ultrafiltration into four peptide fraction viz. Fraction I (> 30kDa), II (10 - 30 kDa), III (1 - 10 kDa) and IV (< 1kDa) which were investigated in terms of their antioxidant activity. The antioxidant activity of hydrolysates and peptide fractions were evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) radical scavenging assays and measuring ferric reducing antioxidant power assay. Scavenging of 2,2′-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) by Fraction III, prepared with ultrasound pretreatment (35 kHz - 30 min) was found to be significantly higher than other fractions (21.17 ± 2.01 % and 80.72 ± 1.32 %, respectively), while ferric reducing antioxidant power assay has proven to be the best for thermal pretreatment. The results show that the fractionated hydrolysates were superior to the original hydrolysate in the antioxidative activity tested and can be concluded that by combining ultrasound pretreatment hydrolysates with improved functional and antioxidant properties can be produced enhancing utilization of egg white in food products.
PB  - Zvornik : Tehnološki fakultet
C3  - Proceedings / IV International Congress "Engineering, Ecology and Materials in the Processing Industry"
T1  - Аntioxidant activity of peptide fractions obtained by membrane ultrafiltration of egg white protein enzymatic hydrolysates
EP  - 286
SP  - 278
DO  - 10.7251/EEMEN1501278K
ER  - 

@conference{
author = "Knežević-Jugović, Zorica and Jovanović, Jelena and Stefanović, Andrea and Žuža, Milena and Šekuljica, Nataša and Manojlović, Verica and Bugarski, Branko",
year = "2015",
abstract = "The objective of this research was a production of egg white protein hydrolysates with improved antioxidant properties. For this purpose, a thermal and ultrasound pretreated egg white proteins were intensively hydrolysed with a commercial food-grade bacterial protease Alcalase. Thus obtained hydrolysates were further separated by sequential ultrafiltration into four peptide fraction viz. Fraction I (> 30kDa), II (10 - 30 kDa), III (1 - 10 kDa) and IV (< 1kDa) which were investigated in terms of their antioxidant activity. The antioxidant activity of hydrolysates and peptide fractions were evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) radical scavenging assays and measuring ferric reducing antioxidant power assay. Scavenging of 2,2′-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) by Fraction III, prepared with ultrasound pretreatment (35 kHz - 30 min) was found to be significantly higher than other fractions (21.17 ± 2.01 % and 80.72 ± 1.32 %, respectively), while ferric reducing antioxidant power assay has proven to be the best for thermal pretreatment. The results show that the fractionated hydrolysates were superior to the original hydrolysate in the antioxidative activity tested and can be concluded that by combining ultrasound pretreatment hydrolysates with improved functional and antioxidant properties can be produced enhancing utilization of egg white in food products.",
publisher = "Zvornik : Tehnološki fakultet",
journal = "Proceedings / IV International Congress "Engineering, Ecology and Materials in the Processing Industry"",
title = "Аntioxidant activity of peptide fractions obtained by membrane ultrafiltration of egg white protein enzymatic hydrolysates",
pages = "286-278",
doi = "10.7251/EEMEN1501278K"
}

Knežević-Jugović, Z., Jovanović, J., Stefanović, A., Žuža, M., Šekuljica, N., Manojlović, V.,& Bugarski, B.. (2015). Аntioxidant activity of peptide fractions obtained by membrane ultrafiltration of egg white protein enzymatic hydrolysates. in Proceedings / IV International Congress "Engineering, Ecology and Materials in the Processing Industry"
Zvornik : Tehnološki fakultet., 278-286.
https://doi.org/10.7251/EEMEN1501278K

Knežević-Jugović Z, Jovanović J, Stefanović A, Žuža M, Šekuljica N, Manojlović V, Bugarski B. Аntioxidant activity of peptide fractions obtained by membrane ultrafiltration of egg white protein enzymatic hydrolysates. in Proceedings / IV International Congress "Engineering, Ecology and Materials in the Processing Industry". 2015;:278-286.
doi:10.7251/EEMEN1501278K .

Knežević-Jugović, Zorica, Jovanović, Jelena, Stefanović, Andrea, Žuža, Milena, Šekuljica, Nataša, Manojlović, Verica, Bugarski, Branko, "Аntioxidant activity of peptide fractions obtained by membrane ultrafiltration of egg white protein enzymatic hydrolysates" in Proceedings / IV International Congress "Engineering, Ecology and Materials in the Processing Industry" (2015):278-286,
https://doi.org/10.7251/EEMEN1501278K . .

TY  - CONF
AU  - Knežević-Jugović, Zorica
AU  - Jovanović, Jelena
AU  - Stefanović, Andrea
AU  - Grbavčić, Sanja
AU  - Šekuljica, Nataša
AU  - Elmalimadi, Mohamed B.
AU  - Bugarski, Branko
PY  - 2015
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6271
AB  - Wheat gluten is a relatively inexpensive industrial byproduct from wheat starch processing, and in
Europe also from manufacturing of bioethanol fuel. Egg producers are also faced with problems of
excess of egg white because mayonnaise industry and bakery industry use relatively high egg yolk
amounts and egg white is the remainder. Of high importance is the production of new value-added
products based on gluten and/or egg white proteins with improved properties and specialized functionality to be used in food and biobased consumer products. The objective of this research was a production of both wheat gluten and egg white protein hydrolysates with improved antioxidant properties. For this purpose, both substrates were pretreated by thermal treatment and then intensively hydrolysed with a commercial food-grade bacterial protease, Alcalase. Thus, the obtained hydrolysates were further separated by sequential ultrafiltration into four peptide fraction viz. Fraction I (> 30kDa), II (10 - 30 kDa), III (1 - 10 kDa) and IV (< 1kDa) which were investigated in terms of their antioxidant activity. The antioxidant activity of hydrolysates and peptide fractions were evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) radical scavenging assays and measuring ferric reducing antioxidant power assay. Scavenging of 2,2′- diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) by Fraction III, prepared with gluten protein was found to be significantly higher than other gluten or egg white fractions. The results show that the fractionated hydrolysates were superior to the original hydrolysate in the antioxidative activity tested in all cases and can be concluded that by combining thermal pretreatment and controlled enzymatic hydrolysis, the hydrolysates with improved antioxidant properties can be produced enhancing utilization of egg white and gluten in food products.
PB  - Bratislava, SK : Slovak Society of Chemical Engineering
C3  - Proceedings / 42nd International Conference of SSCHE Tatranské Matliare
T1  - Hydrolysis of egg white and wheat proteins with protease from bacillus licheniformis: fractionation and identification of bioactive peptides
SP  - 753
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6271
ER  - 

@conference{
author = "Knežević-Jugović, Zorica and Jovanović, Jelena and Stefanović, Andrea and Grbavčić, Sanja and Šekuljica, Nataša and Elmalimadi, Mohamed B. and Bugarski, Branko",
year = "2015",
abstract = "Wheat gluten is a relatively inexpensive industrial byproduct from wheat starch processing, and in
Europe also from manufacturing of bioethanol fuel. Egg producers are also faced with problems of
excess of egg white because mayonnaise industry and bakery industry use relatively high egg yolk
amounts and egg white is the remainder. Of high importance is the production of new value-added
products based on gluten and/or egg white proteins with improved properties and specialized functionality to be used in food and biobased consumer products. The objective of this research was a production of both wheat gluten and egg white protein hydrolysates with improved antioxidant properties. For this purpose, both substrates were pretreated by thermal treatment and then intensively hydrolysed with a commercial food-grade bacterial protease, Alcalase. Thus, the obtained hydrolysates were further separated by sequential ultrafiltration into four peptide fraction viz. Fraction I (> 30kDa), II (10 - 30 kDa), III (1 - 10 kDa) and IV (< 1kDa) which were investigated in terms of their antioxidant activity. The antioxidant activity of hydrolysates and peptide fractions were evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) radical scavenging assays and measuring ferric reducing antioxidant power assay. Scavenging of 2,2′- diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) by Fraction III, prepared with gluten protein was found to be significantly higher than other gluten or egg white fractions. The results show that the fractionated hydrolysates were superior to the original hydrolysate in the antioxidative activity tested in all cases and can be concluded that by combining thermal pretreatment and controlled enzymatic hydrolysis, the hydrolysates with improved antioxidant properties can be produced enhancing utilization of egg white and gluten in food products.",
publisher = "Bratislava, SK : Slovak Society of Chemical Engineering",
journal = "Proceedings / 42nd International Conference of SSCHE Tatranské Matliare",
title = "Hydrolysis of egg white and wheat proteins with protease from bacillus licheniformis: fractionation and identification of bioactive peptides",
pages = "753",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6271"
}

Knežević-Jugović, Z., Jovanović, J., Stefanović, A., Grbavčić, S., Šekuljica, N., Elmalimadi, M. B.,& Bugarski, B.. (2015). Hydrolysis of egg white and wheat proteins with protease from bacillus licheniformis: fractionation and identification of bioactive peptides. in Proceedings / 42nd International Conference of SSCHE Tatranské Matliare
Bratislava, SK : Slovak Society of Chemical Engineering., 753.
https://hdl.handle.net/21.15107/rcub_technorep_6271

Knežević-Jugović Z, Jovanović J, Stefanović A, Grbavčić S, Šekuljica N, Elmalimadi MB, Bugarski B. Hydrolysis of egg white and wheat proteins with protease from bacillus licheniformis: fractionation and identification of bioactive peptides. in Proceedings / 42nd International Conference of SSCHE Tatranské Matliare. 2015;:753.
https://hdl.handle.net/21.15107/rcub_technorep_6271 .

Knežević-Jugović, Zorica, Jovanović, Jelena, Stefanović, Andrea, Grbavčić, Sanja, Šekuljica, Nataša, Elmalimadi, Mohamed B., Bugarski, Branko, "Hydrolysis of egg white and wheat proteins with protease from bacillus licheniformis: fractionation and identification of bioactive peptides" in Proceedings / 42nd International Conference of SSCHE Tatranské Matliare (2015):753,
https://hdl.handle.net/21.15107/rcub_technorep_6271 .

TY  - CONF
AU  - Jovanović, Jelena
AU  - Stefanović, Andrea
AU  - Grbavčić, Sanja
AU  - Šekuljica, Nataša
AU  - Elmalimadi, Mohamed B.
AU  - Bugarski, Branko
AU  - Knežević-Jugović, Zorica
PY  - 2015
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6275
AB  - This contribution was aimed at the fractionation and identification of peptides with improved
antimicrobial activity from egg white protein hydrolysates, obtained by membrane ultrafiltration. For
this purpose, the thermal treated egg white proteins were intensively hydrolysed with a commercial
food-grade bacterial endopeptidase from Bacillus licheniformis, namely Alcalase. Thus, obtained
hydrolysates were further separated by sequential ultrafiltration into four peptide fractions viz. fraction I (> 30kDa), II (10 - 30 kDa), III (1 - 10 kDa) and IV (< 1kDa) which were investigated in terms of their antimicrobial activity. The antimicrobial activity was tested against Gram-positive bacteria (Staphylococcus aureus ATCC 25923), Gram-negative bacteria (Escherichia coli ATCC 25922) and against yeast Candida albicans (ATCC 24433) by fractions' susceptibility of agar diffusion. Our results showed that these peptide fractions have an intense inhibitory activity on Gram-positive bacteria, poor on Gram-negative bacteria and none inhibitory activity on growth of C. albicans. The results showed interesting antimicrobial potentials versus the tested microorganisms, especially fractions with peptides molecular weight of 10-30 kDa and 1-10 kDa. It can be concluded, that the controlled enzymatic hydrolysis of egg white proteins and their subsequent membrane ultrafiltration is considered to be a suitable way for production of biocative peptides with exhibit antimicrobial efficiency.
PB  - Bratislava, SK : Slovak Society of Chemical Engineering
C3  - Proceedings / 42nd International Conference of Slovak Society of Chemical Engineering
T1  - Peptides with improved antimicrobial activity screened by membrane ultrafiltration from egg white protein hydrolysates
EP  - 739
SP  - 732
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6275
ER  - 

@conference{
author = "Jovanović, Jelena and Stefanović, Andrea and Grbavčić, Sanja and Šekuljica, Nataša and Elmalimadi, Mohamed B. and Bugarski, Branko and Knežević-Jugović, Zorica",
year = "2015",
abstract = "This contribution was aimed at the fractionation and identification of peptides with improved
antimicrobial activity from egg white protein hydrolysates, obtained by membrane ultrafiltration. For
this purpose, the thermal treated egg white proteins were intensively hydrolysed with a commercial
food-grade bacterial endopeptidase from Bacillus licheniformis, namely Alcalase. Thus, obtained
hydrolysates were further separated by sequential ultrafiltration into four peptide fractions viz. fraction I (> 30kDa), II (10 - 30 kDa), III (1 - 10 kDa) and IV (< 1kDa) which were investigated in terms of their antimicrobial activity. The antimicrobial activity was tested against Gram-positive bacteria (Staphylococcus aureus ATCC 25923), Gram-negative bacteria (Escherichia coli ATCC 25922) and against yeast Candida albicans (ATCC 24433) by fractions' susceptibility of agar diffusion. Our results showed that these peptide fractions have an intense inhibitory activity on Gram-positive bacteria, poor on Gram-negative bacteria and none inhibitory activity on growth of C. albicans. The results showed interesting antimicrobial potentials versus the tested microorganisms, especially fractions with peptides molecular weight of 10-30 kDa and 1-10 kDa. It can be concluded, that the controlled enzymatic hydrolysis of egg white proteins and their subsequent membrane ultrafiltration is considered to be a suitable way for production of biocative peptides with exhibit antimicrobial efficiency.",
publisher = "Bratislava, SK : Slovak Society of Chemical Engineering",
journal = "Proceedings / 42nd International Conference of Slovak Society of Chemical Engineering",
title = "Peptides with improved antimicrobial activity screened by membrane ultrafiltration from egg white protein hydrolysates",
pages = "739-732",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6275"
}

Jovanović, J., Stefanović, A., Grbavčić, S., Šekuljica, N., Elmalimadi, M. B., Bugarski, B.,& Knežević-Jugović, Z.. (2015). Peptides with improved antimicrobial activity screened by membrane ultrafiltration from egg white protein hydrolysates. in Proceedings / 42nd International Conference of Slovak Society of Chemical Engineering
Bratislava, SK : Slovak Society of Chemical Engineering., 732-739.
https://hdl.handle.net/21.15107/rcub_technorep_6275

Jovanović J, Stefanović A, Grbavčić S, Šekuljica N, Elmalimadi MB, Bugarski B, Knežević-Jugović Z. Peptides with improved antimicrobial activity screened by membrane ultrafiltration from egg white protein hydrolysates. in Proceedings / 42nd International Conference of Slovak Society of Chemical Engineering. 2015;:732-739.
https://hdl.handle.net/21.15107/rcub_technorep_6275 .

Jovanović, Jelena, Stefanović, Andrea, Grbavčić, Sanja, Šekuljica, Nataša, Elmalimadi, Mohamed B., Bugarski, Branko, Knežević-Jugović, Zorica, "Peptides with improved antimicrobial activity screened by membrane ultrafiltration from egg white protein hydrolysates" in Proceedings / 42nd International Conference of Slovak Society of Chemical Engineering (2015):732-739,
https://hdl.handle.net/21.15107/rcub_technorep_6275 .

TY  - CONF
AU  - Jovanović, Jelena
AU  - Stefanović, Andrea
AU  - Žuža Prastalo, Milena
AU  - Šekuljica, Nataša
AU  - Jakovetić Tanasković, Sonja
AU  - Luković, Nevena
AU  - Knežević-Jugović, Zorica
PY  - 2014
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6264
AB  - U ovom radu ispitivan je uticaj koncentacije enzima, supstrata i temperature
na početnu brzinu reakcije hidrolize proteina belanceta katalizovane Alkalazom 2,4 L
(proteaza iz Bacillus licheniformis). Glavni cilj ovog istraživanja bio je ispitivanje
uticaja ultrazvučnih talasa na brzinu reakcije hidrolize, kao i modelovanje enzimskog
procesa hidrolize proteina belanceta u cilju dobijanja projektnih jednačina neophodnih
za projektovanje i dizajn enzimskog reaktora. Kao supstrat korišćen je 10% w/w rastvor
belanceta prethodno tretiran ultrazvučnim talasima frekvencije 35 kHz u toku 30
minuta. Dobijeni eksperimentalni rezultati modelovani su kinetičkim modelom koji
uzima u obzir inhibiciju supstratom i deaktivaciju enzima. Predloženi kinetički model
dao je dobro slaganje sa dobijenim eksperimentalnim rezultatima. Izračunate kinetičke
konstante ukazuju da pretretman ultrazvučnim talasima dovodi do povećanja stepena
hidrolize.
PB  - Čačak : Agronomski fakultet
C3  - Zbornik radova / XIX Savetovanje o biotehnologiji sa međunarodnim učešćem
T1  - Empirijski kinetički model hidrolize proteina belanceta pretretiranih ultrazvučnim talasima visoke frekvencije
EP  - 285
IS  - 21
SP  - 281
VL  - 19
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6264
ER  - 

@conference{
author = "Jovanović, Jelena and Stefanović, Andrea and Žuža Prastalo, Milena and Šekuljica, Nataša and Jakovetić Tanasković, Sonja and Luković, Nevena and Knežević-Jugović, Zorica",
year = "2014",
abstract = "U ovom radu ispitivan je uticaj koncentacije enzima, supstrata i temperature
na početnu brzinu reakcije hidrolize proteina belanceta katalizovane Alkalazom 2,4 L
(proteaza iz Bacillus licheniformis). Glavni cilj ovog istraživanja bio je ispitivanje
uticaja ultrazvučnih talasa na brzinu reakcije hidrolize, kao i modelovanje enzimskog
procesa hidrolize proteina belanceta u cilju dobijanja projektnih jednačina neophodnih
za projektovanje i dizajn enzimskog reaktora. Kao supstrat korišćen je 10% w/w rastvor
belanceta prethodno tretiran ultrazvučnim talasima frekvencije 35 kHz u toku 30
minuta. Dobijeni eksperimentalni rezultati modelovani su kinetičkim modelom koji
uzima u obzir inhibiciju supstratom i deaktivaciju enzima. Predloženi kinetički model
dao je dobro slaganje sa dobijenim eksperimentalnim rezultatima. Izračunate kinetičke
konstante ukazuju da pretretman ultrazvučnim talasima dovodi do povećanja stepena
hidrolize.",
publisher = "Čačak : Agronomski fakultet",
journal = "Zbornik radova / XIX Savetovanje o biotehnologiji sa međunarodnim učešćem",
title = "Empirijski kinetički model hidrolize proteina belanceta pretretiranih ultrazvučnim talasima visoke frekvencije",
pages = "285-281",
number = "21",
volume = "19",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6264"
}

Jovanović, J., Stefanović, A., Žuža Prastalo, M., Šekuljica, N., Jakovetić Tanasković, S., Luković, N.,& Knežević-Jugović, Z.. (2014). Empirijski kinetički model hidrolize proteina belanceta pretretiranih ultrazvučnim talasima visoke frekvencije. in Zbornik radova / XIX Savetovanje o biotehnologiji sa međunarodnim učešćem
Čačak : Agronomski fakultet., 19(21), 281-285.
https://hdl.handle.net/21.15107/rcub_technorep_6264

Jovanović J, Stefanović A, Žuža Prastalo M, Šekuljica N, Jakovetić Tanasković S, Luković N, Knežević-Jugović Z. Empirijski kinetički model hidrolize proteina belanceta pretretiranih ultrazvučnim talasima visoke frekvencije. in Zbornik radova / XIX Savetovanje o biotehnologiji sa međunarodnim učešćem. 2014;19(21):281-285.
https://hdl.handle.net/21.15107/rcub_technorep_6264 .

Jovanović, Jelena, Stefanović, Andrea, Žuža Prastalo, Milena, Šekuljica, Nataša, Jakovetić Tanasković, Sonja, Luković, Nevena, Knežević-Jugović, Zorica, "Empirijski kinetički model hidrolize proteina belanceta pretretiranih ultrazvučnim talasima visoke frekvencije" in Zbornik radova / XIX Savetovanje o biotehnologiji sa međunarodnim učešćem, 19, no. 21 (2014):281-285,
https://hdl.handle.net/21.15107/rcub_technorep_6264 .

TY  - CONF
AU  - Žuža Prastalo, Milena
AU  - Gluvić, Ana
AU  - Jakovetić Tanasković, Sonja
AU  - Luković, Nevena
AU  - Stefanović, Andrea
AU  - Jovanović, Jelena
AU  - Knežević-Jugović, Zorica
PY  - 2014
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6265
AB  - Hidrolizom proteina belanceta dobijaju se bioaktivni peptidi koji imaju
različita biološka svojstva. U ovom radu korišćena je tehnologija ultrazvuka visokog
intenziteta kao pretretman pripreme proteina belanceta koji su zatim hidrolizovani
različitim vrstama proteaza u jednostepenom i dvostepenom postupku. Dobijeni
hidrolizati su razdvojeni korišćenjem ultrafiltracionih membrana promera 1, 10 i 30 kDa
i dobijenim frakcijama je ispitana antioksidativna aktivnost. Među frakcijama veličine
manje od 1 kDa koje sadrže bioaktivne peptide, najveću antioksidativnu aktivnost je
pokazao ultrazvučno pretretiran hidrolizat nastao delovanjem alkalaza-flevorzima u
dvostepenom enzimskom postupku.
PB  - Čačak : Agronomski fakultet
C3  - Zbornik radova / XIX Savetovanje o biotehnologiji sa međunarodnim učešćem
T1  - Antioksidativna aktivnost hidrolizata belanceta i njegovih frakcija dobijenih membranskom ultrafiltracijom
EP  - 279
IS  - 21
SP  - 275
VL  - 19
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6265
ER  - 

@conference{
author = "Žuža Prastalo, Milena and Gluvić, Ana and Jakovetić Tanasković, Sonja and Luković, Nevena and Stefanović, Andrea and Jovanović, Jelena and Knežević-Jugović, Zorica",
year = "2014",
abstract = "Hidrolizom proteina belanceta dobijaju se bioaktivni peptidi koji imaju
različita biološka svojstva. U ovom radu korišćena je tehnologija ultrazvuka visokog
intenziteta kao pretretman pripreme proteina belanceta koji su zatim hidrolizovani
različitim vrstama proteaza u jednostepenom i dvostepenom postupku. Dobijeni
hidrolizati su razdvojeni korišćenjem ultrafiltracionih membrana promera 1, 10 i 30 kDa
i dobijenim frakcijama je ispitana antioksidativna aktivnost. Među frakcijama veličine
manje od 1 kDa koje sadrže bioaktivne peptide, najveću antioksidativnu aktivnost je
pokazao ultrazvučno pretretiran hidrolizat nastao delovanjem alkalaza-flevorzima u
dvostepenom enzimskom postupku.",
publisher = "Čačak : Agronomski fakultet",
journal = "Zbornik radova / XIX Savetovanje o biotehnologiji sa međunarodnim učešćem",
title = "Antioksidativna aktivnost hidrolizata belanceta i njegovih frakcija dobijenih membranskom ultrafiltracijom",
pages = "279-275",
number = "21",
volume = "19",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6265"
}

Žuža Prastalo, M., Gluvić, A., Jakovetić Tanasković, S., Luković, N., Stefanović, A., Jovanović, J.,& Knežević-Jugović, Z.. (2014). Antioksidativna aktivnost hidrolizata belanceta i njegovih frakcija dobijenih membranskom ultrafiltracijom. in Zbornik radova / XIX Savetovanje o biotehnologiji sa međunarodnim učešćem
Čačak : Agronomski fakultet., 19(21), 275-279.
https://hdl.handle.net/21.15107/rcub_technorep_6265

Žuža Prastalo M, Gluvić A, Jakovetić Tanasković S, Luković N, Stefanović A, Jovanović J, Knežević-Jugović Z. Antioksidativna aktivnost hidrolizata belanceta i njegovih frakcija dobijenih membranskom ultrafiltracijom. in Zbornik radova / XIX Savetovanje o biotehnologiji sa međunarodnim učešćem. 2014;19(21):275-279.
https://hdl.handle.net/21.15107/rcub_technorep_6265 .

Žuža Prastalo, Milena, Gluvić, Ana, Jakovetić Tanasković, Sonja, Luković, Nevena, Stefanović, Andrea, Jovanović, Jelena, Knežević-Jugović, Zorica, "Antioksidativna aktivnost hidrolizata belanceta i njegovih frakcija dobijenih membranskom ultrafiltracijom" in Zbornik radova / XIX Savetovanje o biotehnologiji sa međunarodnim učešćem, 19, no. 21 (2014):275-279,
https://hdl.handle.net/21.15107/rcub_technorep_6265 .

TY  - CONF
AU  - Jovanović, Jelena
AU  - Stefanović, Andrea
AU  - Jakovetić Tanasković, Sonja
AU  - Luković, Nevena
AU  - Šekuljica, Nataša
AU  - Žuža Praštalo, Milena
AU  - Knežević-Jugović, Zorica
PY  - 2014
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6277
AB  - The objective of this study was to investigate the effect of ultrasound pretreatment on two-step enzymatic hydrolysis of egg white proteins (EWPs) using commercial food-grade proteases as well as evaluating some functional properties of obtained hydrolysates. 
Three commercially available proteases used in this work were: alcalase from Bacillus licheniformis, neutrase from Bacillus amyloliquefaciens and flavourzyme from Aspergillus oryzae. Thus obtained hydrolysates were further separated by sequential ultrafiltration into three peptide fraction viz. Fraction I (< 1kDa), II (1 - 10 kDa), III (10 - 30 kDa) which were investigated in terms of their antioxidant activity. The antioxidant activity of hydrolysates and peptide fractions were evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. 
Comparing the hydrolytic curves of two-step enzymatic process, the highest equilibrium degree of hydrolysis (DH) was achieved by a combination of alcalase and neutrase. The order of addition of these two proteolytic enzymes didn't lead to significant differences in the initial rate of reaction, but significantly affected the equilibrium DH (32.25 ± 2.08%). The two-step hydrolysis, in which flavourzyme is followed by alcalase, seemed to perform with the same initial rate, but DH was considerably lower (28.23 ± 0.91%). Two-step enzymatic hydrolysis appeared to increase solubility and substantially improved the foam stability while the foam capacity didn't change significantly vs. control. The high yield of peptides soluble at pH 6 and pH 8 were obtained by combination of alcalase and flavourzyme while more voluminous foams were obtained with alcalase and neutrase. The most abundant fraction in terms of antioxidant activity was the Fraction II, which indicates that the combination of alcalase and flavourzyme was efficient at reducing the pretreated into low molecular weight peptides. 
This study showed that by combining ultrasound pretreatment under controlled conditions with careful proteases selection, hydrolysates with improved functional and antioxidant properties can be produced enhancing utilization of egg white in food products.
PB  - Skopje, Macedonia : Consulting and training center - KEY
C3  - Book of Abstracts / 1st Conference on Food Quality and Safety, Health and Nutrition - NUTRICON 2014
T1  - Antioxidant activity and functional properties of peptides derived from egg white proteins by two-step enzymatic hydrolysis
EP  - 77
SP  - 76
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6277
ER  - 

@conference{
author = "Jovanović, Jelena and Stefanović, Andrea and Jakovetić Tanasković, Sonja and Luković, Nevena and Šekuljica, Nataša and Žuža Praštalo, Milena and Knežević-Jugović, Zorica",
year = "2014",
abstract = "The objective of this study was to investigate the effect of ultrasound pretreatment on two-step enzymatic hydrolysis of egg white proteins (EWPs) using commercial food-grade proteases as well as evaluating some functional properties of obtained hydrolysates. 
Three commercially available proteases used in this work were: alcalase from Bacillus licheniformis, neutrase from Bacillus amyloliquefaciens and flavourzyme from Aspergillus oryzae. Thus obtained hydrolysates were further separated by sequential ultrafiltration into three peptide fraction viz. Fraction I (< 1kDa), II (1 - 10 kDa), III (10 - 30 kDa) which were investigated in terms of their antioxidant activity. The antioxidant activity of hydrolysates and peptide fractions were evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay. 
Comparing the hydrolytic curves of two-step enzymatic process, the highest equilibrium degree of hydrolysis (DH) was achieved by a combination of alcalase and neutrase. The order of addition of these two proteolytic enzymes didn't lead to significant differences in the initial rate of reaction, but significantly affected the equilibrium DH (32.25 ± 2.08%). The two-step hydrolysis, in which flavourzyme is followed by alcalase, seemed to perform with the same initial rate, but DH was considerably lower (28.23 ± 0.91%). Two-step enzymatic hydrolysis appeared to increase solubility and substantially improved the foam stability while the foam capacity didn't change significantly vs. control. The high yield of peptides soluble at pH 6 and pH 8 were obtained by combination of alcalase and flavourzyme while more voluminous foams were obtained with alcalase and neutrase. The most abundant fraction in terms of antioxidant activity was the Fraction II, which indicates that the combination of alcalase and flavourzyme was efficient at reducing the pretreated into low molecular weight peptides. 
This study showed that by combining ultrasound pretreatment under controlled conditions with careful proteases selection, hydrolysates with improved functional and antioxidant properties can be produced enhancing utilization of egg white in food products.",
publisher = "Skopje, Macedonia : Consulting and training center - KEY",
journal = "Book of Abstracts / 1st Conference on Food Quality and Safety, Health and Nutrition - NUTRICON 2014",
title = "Antioxidant activity and functional properties of peptides derived from egg white proteins by two-step enzymatic hydrolysis",
pages = "77-76",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6277"
}

Jovanović, J., Stefanović, A., Jakovetić Tanasković, S., Luković, N., Šekuljica, N., Žuža Praštalo, M.,& Knežević-Jugović, Z.. (2014). Antioxidant activity and functional properties of peptides derived from egg white proteins by two-step enzymatic hydrolysis. in Book of Abstracts / 1st Conference on Food Quality and Safety, Health and Nutrition - NUTRICON 2014
Skopje, Macedonia : Consulting and training center - KEY., 76-77.
https://hdl.handle.net/21.15107/rcub_technorep_6277

Jovanović J, Stefanović A, Jakovetić Tanasković S, Luković N, Šekuljica N, Žuža Praštalo M, Knežević-Jugović Z. Antioxidant activity and functional properties of peptides derived from egg white proteins by two-step enzymatic hydrolysis. in Book of Abstracts / 1st Conference on Food Quality and Safety, Health and Nutrition - NUTRICON 2014. 2014;:76-77.
https://hdl.handle.net/21.15107/rcub_technorep_6277 .

Jovanović, Jelena, Stefanović, Andrea, Jakovetić Tanasković, Sonja, Luković, Nevena, Šekuljica, Nataša, Žuža Praštalo, Milena, Knežević-Jugović, Zorica, "Antioxidant activity and functional properties of peptides derived from egg white proteins by two-step enzymatic hydrolysis" in Book of Abstracts / 1st Conference on Food Quality and Safety, Health and Nutrition - NUTRICON 2014 (2014):76-77,
https://hdl.handle.net/21.15107/rcub_technorep_6277 .

TY  - CONF
AU  - Knežević-Jugović, Zorica
AU  - Stefanović, Andrea
AU  - Jovanović, Jelena
AU  - Žuža Praštalo, Milena
AU  - Grbavčić, Sanja
AU  - Jakovetić Tanasković, Sonja
AU  - Dojčinović, Marina
AU  - Luković, Nevena
PY  - 2014
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6281
AB  - The effects of the ultrasound pretreatment on functional properties of egg white proteins (EWPs) and
their subsequent hydrolysis by Alcalase were investigated. Functional properties of the obtained
hydrolysates were characterized in terms of solubility, turbidity, emulsification activity and foaming
properties. The ultrasound pretreatment at 20 kHz for 15 min by using ultrasound probe has been
shown to accelerate the hydrolysis process and generate more reproducible results, compared with
both, heat treatment or treatment in an ultrasonic water baths at 40 kHz under similar conditions. It was
also shown that the ultrasound pretreatment resulted in an increase in total and reactive thiol content,
suggesting an unfolding of the protein molecules. Minor secondary and tertiary structural changes have
also been confirmed by circular dichroism. The produced hydrolysate, under optimum condition, was
characterized in terms of antioxidant properties and peptide composition.
Industrial relevance: Egg producers are faced with problems of excess of egg white because
mayonnaise industry and bakery industry use relatively high egg yolk amounts and egg white is
remainder. In this work, EWPs was treated by high intensity ultrasound and then hydrolyzed by
Alcalase. Effects of treatment time on the functional properties of EWPs and susceptibility to
proteolysis were investigated. The results showed that the ultrasound technology could improve
functional and antioxidant activity of EWPs under the controlled conditions.
PB  - Slovakia : Slovak Society of Chemical Engineering
C3  - Proceedings / 41st International Conference of Slovak Society of Chemical Engineering
T1  - Ultrasound-induced changes in functional properties of egg white proteins and in their susceptibility to enzymatic hydrolysis
EP  - 135
SP  - 126
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6281
ER  - 

@conference{
author = "Knežević-Jugović, Zorica and Stefanović, Andrea and Jovanović, Jelena and Žuža Praštalo, Milena and Grbavčić, Sanja and Jakovetić Tanasković, Sonja and Dojčinović, Marina and Luković, Nevena",
year = "2014",
abstract = "The effects of the ultrasound pretreatment on functional properties of egg white proteins (EWPs) and
their subsequent hydrolysis by Alcalase were investigated. Functional properties of the obtained
hydrolysates were characterized in terms of solubility, turbidity, emulsification activity and foaming
properties. The ultrasound pretreatment at 20 kHz for 15 min by using ultrasound probe has been
shown to accelerate the hydrolysis process and generate more reproducible results, compared with
both, heat treatment or treatment in an ultrasonic water baths at 40 kHz under similar conditions. It was
also shown that the ultrasound pretreatment resulted in an increase in total and reactive thiol content,
suggesting an unfolding of the protein molecules. Minor secondary and tertiary structural changes have
also been confirmed by circular dichroism. The produced hydrolysate, under optimum condition, was
characterized in terms of antioxidant properties and peptide composition.
Industrial relevance: Egg producers are faced with problems of excess of egg white because
mayonnaise industry and bakery industry use relatively high egg yolk amounts and egg white is
remainder. In this work, EWPs was treated by high intensity ultrasound and then hydrolyzed by
Alcalase. Effects of treatment time on the functional properties of EWPs and susceptibility to
proteolysis were investigated. The results showed that the ultrasound technology could improve
functional and antioxidant activity of EWPs under the controlled conditions.",
publisher = "Slovakia : Slovak Society of Chemical Engineering",
journal = "Proceedings / 41st International Conference of Slovak Society of Chemical Engineering",
title = "Ultrasound-induced changes in functional properties of egg white proteins and in their susceptibility to enzymatic hydrolysis",
pages = "135-126",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6281"
}

Knežević-Jugović, Z., Stefanović, A., Jovanović, J., Žuža Praštalo, M., Grbavčić, S., Jakovetić Tanasković, S., Dojčinović, M.,& Luković, N.. (2014). Ultrasound-induced changes in functional properties of egg white proteins and in their susceptibility to enzymatic hydrolysis. in Proceedings / 41st International Conference of Slovak Society of Chemical Engineering
Slovakia : Slovak Society of Chemical Engineering., 126-135.
https://hdl.handle.net/21.15107/rcub_technorep_6281

Knežević-Jugović Z, Stefanović A, Jovanović J, Žuža Praštalo M, Grbavčić S, Jakovetić Tanasković S, Dojčinović M, Luković N. Ultrasound-induced changes in functional properties of egg white proteins and in their susceptibility to enzymatic hydrolysis. in Proceedings / 41st International Conference of Slovak Society of Chemical Engineering. 2014;:126-135.
https://hdl.handle.net/21.15107/rcub_technorep_6281 .

Knežević-Jugović, Zorica, Stefanović, Andrea, Jovanović, Jelena, Žuža Praštalo, Milena, Grbavčić, Sanja, Jakovetić Tanasković, Sonja, Dojčinović, Marina, Luković, Nevena, "Ultrasound-induced changes in functional properties of egg white proteins and in their susceptibility to enzymatic hydrolysis" in Proceedings / 41st International Conference of Slovak Society of Chemical Engineering (2014):126-135,
https://hdl.handle.net/21.15107/rcub_technorep_6281 .

TY  - JOUR
AU  - Stefanović, Andrea
AU  - Jovanović, Jelena
AU  - Dojčinović, Marina
AU  - Lević, Steva
AU  - Žuža Praštalo, Milena
AU  - Nedović, Viktor
AU  - Knežević-Jugović, Zorica
PY  - 2014
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6249
AB  - High-intensity ultrasound represents a non-thermal processing method that has been extensively researched and used in the last decade. The application of power ultrasound offers the opportunity to modify and improve some technologically important compounds which are often used in food products, such as proteins. The focus of this research was to evaluate the effect of high-intensity ultrasound on egg white proteins (EWPs) with an objective to improve their functional properties. 
In this study, 10% (w/w) aqueous solution of egg white was treated with ultrasound probe which frequency was 20 kHz and treatments were performed for 5, 10, 15 and 20 min. The effect of the treatment was examined for aforementioned properties: the change of pH and temperature, solubility, foaming by a whipping method, emulsifying by turbidometric technique, sulfydryl content (exposed and total SH groups), antioxidant and antimicrobial activity and susceptibility of treated samples to enzymatic hydrolysis. 
Ultrasound affected functional properties of egg white proteins and improved antioxidant and antimicrobial activity. Furthermore, the samples showed an increased concentration of the total SH groups, while the concentration of exposed SH groups was not affected. pH did not change significantly upon the ultrasound treatment, while the temperature of the egg white solutions increased. 
These results suggest that high-intensity ultrasound probe can be used for improvement of the functionality of the EWPs and thus it could be potentially applied in the food industries. The trials reported here may represent relevant information to consider when attempt¬ing the use of high-intensity treatment for improving functional properties.
PB  - Skopje, Macedonia : Consulting and Training Center - KEY
T2  - Journal of Hygienic Engineering and Design
T1  - Impact of high-intensity ultrasound probe on the functionality of egg white proteins
EP  - 224
SP  - 215
VL  - 6
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6249
ER  - 

@article{
author = "Stefanović, Andrea and Jovanović, Jelena and Dojčinović, Marina and Lević, Steva and Žuža Praštalo, Milena and Nedović, Viktor and Knežević-Jugović, Zorica",
year = "2014",
abstract = "High-intensity ultrasound represents a non-thermal processing method that has been extensively researched and used in the last decade. The application of power ultrasound offers the opportunity to modify and improve some technologically important compounds which are often used in food products, such as proteins. The focus of this research was to evaluate the effect of high-intensity ultrasound on egg white proteins (EWPs) with an objective to improve their functional properties. 
In this study, 10% (w/w) aqueous solution of egg white was treated with ultrasound probe which frequency was 20 kHz and treatments were performed for 5, 10, 15 and 20 min. The effect of the treatment was examined for aforementioned properties: the change of pH and temperature, solubility, foaming by a whipping method, emulsifying by turbidometric technique, sulfydryl content (exposed and total SH groups), antioxidant and antimicrobial activity and susceptibility of treated samples to enzymatic hydrolysis. 
Ultrasound affected functional properties of egg white proteins and improved antioxidant and antimicrobial activity. Furthermore, the samples showed an increased concentration of the total SH groups, while the concentration of exposed SH groups was not affected. pH did not change significantly upon the ultrasound treatment, while the temperature of the egg white solutions increased. 
These results suggest that high-intensity ultrasound probe can be used for improvement of the functionality of the EWPs and thus it could be potentially applied in the food industries. The trials reported here may represent relevant information to consider when attempt¬ing the use of high-intensity treatment for improving functional properties.",
publisher = "Skopje, Macedonia : Consulting and Training Center - KEY",
journal = "Journal of Hygienic Engineering and Design",
title = "Impact of high-intensity ultrasound probe on the functionality of egg white proteins",
pages = "224-215",
volume = "6",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6249"
}

Stefanović, A., Jovanović, J., Dojčinović, M., Lević, S., Žuža Praštalo, M., Nedović, V.,& Knežević-Jugović, Z.. (2014). Impact of high-intensity ultrasound probe on the functionality of egg white proteins. in Journal of Hygienic Engineering and Design
Skopje, Macedonia : Consulting and Training Center - KEY., 6, 215-224.
https://hdl.handle.net/21.15107/rcub_technorep_6249

Stefanović A, Jovanović J, Dojčinović M, Lević S, Žuža Praštalo M, Nedović V, Knežević-Jugović Z. Impact of high-intensity ultrasound probe on the functionality of egg white proteins. in Journal of Hygienic Engineering and Design. 2014;6:215-224.
https://hdl.handle.net/21.15107/rcub_technorep_6249 .

Stefanović, Andrea, Jovanović, Jelena, Dojčinović, Marina, Lević, Steva, Žuža Praštalo, Milena, Nedović, Viktor, Knežević-Jugović, Zorica, "Impact of high-intensity ultrasound probe on the functionality of egg white proteins" in Journal of Hygienic Engineering and Design, 6 (2014):215-224,
https://hdl.handle.net/21.15107/rcub_technorep_6249 .

TY  - CONF
AU  - Knežević-Jugović, Zorica
AU  - Žuža, Milena
AU  - Gluvić, Ana
AU  - Jovanović, Jelena
AU  - Stefanović, Andrea
AU  - Manojlović, Verica
AU  - Bugarski, Branko
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6279
AB  - Enzymatic hydrolysis of egg white proteins (EWPs) has shown a great potential to improve their functional properties such as increased solubility, stability, and digestibility while still retaining their nutrition value. The high selectivity and mild reaction conditions associated with the enzymatic process have made this approach an attractive alternative in the production of EWPs with improved functional properties, which are often difficult to obtain by conventional chemical route. Moreover, the inherent specificity of various proteolytic enzymes should control the nature and extent of hydrolysis and thus the functional properties of the product.
The focus of this work is to find the best combination of enzymes and the mode of both substrate pretreatment and process implementation for improvement of the overall hydrolysates` quality. For this purpose EWP solution was hydrolysed with several enzymes using both, one-step and two-step hydrolysis in a stirred stirred-tank reactor employing an enzyme to protein substrate weight ratio previously selected to obtain the desired level of conversion in the first step within a time period from about 20 to about 75 minutes depending of protease used. The obtained hydrolysates were then tested on antioxidant activity, flavour, solubility, digestibility emulsifying activity, foaming capacity and stability. Selected results have been presented in Figure 1.
The application of two-step enzymatic process, based on the use of the bacterial alkaline protease in the first step, and then the introduction a more specific protease in the second step to selectively reduce the bitter peptides, seemed to be advantageous.
PB  - Belgrade : Serbian Chemical Society
C3  - Book of abstracts / 8th International Conference of the Chemical Societies of the South-East European Countries - ICOSECS
T1  - Biochemical and funcional properties of egg white hydrolysates produced by different proteases
SP  - 232
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6279
ER  - 

@conference{
author = "Knežević-Jugović, Zorica and Žuža, Milena and Gluvić, Ana and Jovanović, Jelena and Stefanović, Andrea and Manojlović, Verica and Bugarski, Branko",
year = "2013",
abstract = "Enzymatic hydrolysis of egg white proteins (EWPs) has shown a great potential to improve their functional properties such as increased solubility, stability, and digestibility while still retaining their nutrition value. The high selectivity and mild reaction conditions associated with the enzymatic process have made this approach an attractive alternative in the production of EWPs with improved functional properties, which are often difficult to obtain by conventional chemical route. Moreover, the inherent specificity of various proteolytic enzymes should control the nature and extent of hydrolysis and thus the functional properties of the product.
The focus of this work is to find the best combination of enzymes and the mode of both substrate pretreatment and process implementation for improvement of the overall hydrolysates` quality. For this purpose EWP solution was hydrolysed with several enzymes using both, one-step and two-step hydrolysis in a stirred stirred-tank reactor employing an enzyme to protein substrate weight ratio previously selected to obtain the desired level of conversion in the first step within a time period from about 20 to about 75 minutes depending of protease used. The obtained hydrolysates were then tested on antioxidant activity, flavour, solubility, digestibility emulsifying activity, foaming capacity and stability. Selected results have been presented in Figure 1.
The application of two-step enzymatic process, based on the use of the bacterial alkaline protease in the first step, and then the introduction a more specific protease in the second step to selectively reduce the bitter peptides, seemed to be advantageous.",
publisher = "Belgrade : Serbian Chemical Society",
journal = "Book of abstracts / 8th International Conference of the Chemical Societies of the South-East European Countries - ICOSECS",
title = "Biochemical and funcional properties of egg white hydrolysates produced by different proteases",
pages = "232",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6279"
}

Knežević-Jugović, Z., Žuža, M., Gluvić, A., Jovanović, J., Stefanović, A., Manojlović, V.,& Bugarski, B.. (2013). Biochemical and funcional properties of egg white hydrolysates produced by different proteases. in Book of abstracts / 8th International Conference of the Chemical Societies of the South-East European Countries - ICOSECS
Belgrade : Serbian Chemical Society., 232.
https://hdl.handle.net/21.15107/rcub_technorep_6279

Knežević-Jugović Z, Žuža M, Gluvić A, Jovanović J, Stefanović A, Manojlović V, Bugarski B. Biochemical and funcional properties of egg white hydrolysates produced by different proteases. in Book of abstracts / 8th International Conference of the Chemical Societies of the South-East European Countries - ICOSECS. 2013;:232.
https://hdl.handle.net/21.15107/rcub_technorep_6279 .

Knežević-Jugović, Zorica, Žuža, Milena, Gluvić, Ana, Jovanović, Jelena, Stefanović, Andrea, Manojlović, Verica, Bugarski, Branko, "Biochemical and funcional properties of egg white hydrolysates produced by different proteases" in Book of abstracts / 8th International Conference of the Chemical Societies of the South-East European Countries - ICOSECS (2013):232,
https://hdl.handle.net/21.15107/rcub_technorep_6279 .

TY  - CONF
AU  - Stefanović, Andrea
AU  - Jovanović, Jelena
AU  - Gluvić, Ana
AU  - Jakovetić Tanasković, Sonja
AU  - Luković, Nevena
AU  - Žuža Praštalo, Milena
AU  - Knežević-Jugović, Zorica
PY  - 2013
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6278
AB  - The kinetics of hydrolysis of egg white proteins by Alcalase 2.4L (protease from Bacillus licheniformis) was investigated. In this paper, the main objective was to determine the
appropriate empirical model for the proteolytic hydrolysis of egg white. A logarithmic
equation X = (1/b) ln (1 + abt) indicating the relationship between the degree of hydrolysis
(DH) and time was established. Experimental data were successfully fitted with kinetic
model taking into account the enzyme inactivation and substrate inhibition, and related
kinetic constants were determined. The kinetic study was performed at optimum process
parameters: initial enzyme concentration of Alcalase 2.4L, initial substrate concentration
of the egg white proteins and different temperatures of the reaction. The kinetic and
thermodynamic constants for reaction of hydrolysis (Ki = 320.07 mg cm-3, k2 =0.0104 min-1,
kd = 0.0743 min-1, Ea = 103.04 kJ mol-1, Ed = 99.52 kJ mol-1) were responsible for the
empirical equation. Kinetic constants of the hydrolysis were determined, and good
congruence between the model and experimental data was achieved. The results of
nonlinear regression of the proposed kinetic model agreed with the experimental data,
thus the kinetic equations can be used to fit the enzymatic hydrolysis process of egg white
protein and to optimize the operating parameters for the bioreactor design.
PB  - Belgrade : Serbian Chemical Society
C3  - Book of abstracts / 8th International Conference of the Chemical Societies of the South-East European Countries - ICOSECS
T1  - Kinetic model of the hydrolysis of egg white proteins by Alcalase
SP  - 235
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6278
ER  - 

@conference{
author = "Stefanović, Andrea and Jovanović, Jelena and Gluvić, Ana and Jakovetić Tanasković, Sonja and Luković, Nevena and Žuža Praštalo, Milena and Knežević-Jugović, Zorica",
year = "2013",
abstract = "The kinetics of hydrolysis of egg white proteins by Alcalase 2.4L (protease from Bacillus licheniformis) was investigated. In this paper, the main objective was to determine the
appropriate empirical model for the proteolytic hydrolysis of egg white. A logarithmic
equation X = (1/b) ln (1 + abt) indicating the relationship between the degree of hydrolysis
(DH) and time was established. Experimental data were successfully fitted with kinetic
model taking into account the enzyme inactivation and substrate inhibition, and related
kinetic constants were determined. The kinetic study was performed at optimum process
parameters: initial enzyme concentration of Alcalase 2.4L, initial substrate concentration
of the egg white proteins and different temperatures of the reaction. The kinetic and
thermodynamic constants for reaction of hydrolysis (Ki = 320.07 mg cm-3, k2 =0.0104 min-1,
kd = 0.0743 min-1, Ea = 103.04 kJ mol-1, Ed = 99.52 kJ mol-1) were responsible for the
empirical equation. Kinetic constants of the hydrolysis were determined, and good
congruence between the model and experimental data was achieved. The results of
nonlinear regression of the proposed kinetic model agreed with the experimental data,
thus the kinetic equations can be used to fit the enzymatic hydrolysis process of egg white
protein and to optimize the operating parameters for the bioreactor design.",
publisher = "Belgrade : Serbian Chemical Society",
journal = "Book of abstracts / 8th International Conference of the Chemical Societies of the South-East European Countries - ICOSECS",
title = "Kinetic model of the hydrolysis of egg white proteins by Alcalase",
pages = "235",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6278"
}

Stefanović, A., Jovanović, J., Gluvić, A., Jakovetić Tanasković, S., Luković, N., Žuža Praštalo, M.,& Knežević-Jugović, Z.. (2013). Kinetic model of the hydrolysis of egg white proteins by Alcalase. in Book of abstracts / 8th International Conference of the Chemical Societies of the South-East European Countries - ICOSECS
Belgrade : Serbian Chemical Society., 235.
https://hdl.handle.net/21.15107/rcub_technorep_6278

Stefanović A, Jovanović J, Gluvić A, Jakovetić Tanasković S, Luković N, Žuža Praštalo M, Knežević-Jugović Z. Kinetic model of the hydrolysis of egg white proteins by Alcalase. in Book of abstracts / 8th International Conference of the Chemical Societies of the South-East European Countries - ICOSECS. 2013;:235.
https://hdl.handle.net/21.15107/rcub_technorep_6278 .

Stefanović, Andrea, Jovanović, Jelena, Gluvić, Ana, Jakovetić Tanasković, Sonja, Luković, Nevena, Žuža Praštalo, Milena, Knežević-Jugović, Zorica, "Kinetic model of the hydrolysis of egg white proteins by Alcalase" in Book of abstracts / 8th International Conference of the Chemical Societies of the South-East European Countries - ICOSECS (2013):235,
https://hdl.handle.net/21.15107/rcub_technorep_6278 .