TY  - CONF
AU  - Vukoičić, Ana
AU  - Milivojević, Ana
AU  - Banjanac, Katarina
AU  - Petrov Ivanković, Anja
AU  - Ćorović, Marija
AU  - Marinković, Aleksandar
AU  - Palomo, Jose Miguel
AU  - Bezbradica, Dejan
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6844
AB  - Flavonoids are a big class of plants’ secondary metabolites which possess antimicrobial, antioxidative, anti-inflammatory, etc. activities. However, their wider application is limited due to their poor solubility and stability in different environments. In order to overcome this problem and improve their biological and physicochemical characteristics, enzymatic oligomerization of flavonoids can be performed by using laccases as biocatalyst. In this study, laccase from Trametes versicolor was successfully immobilized onto two nanocarriers and used as a catalyst for the oligomerization of two flavonoids, esculin and phloridzin. For immobilization, nanocelulose prepared by ultrasonic treatment of commercial microcellulose and nanosilica from rice were used. Both carriers were modified in order to introduce amino groups on their surface: nanocelulose with poly(ethyleneimine) (NC-PEI) and nanosilica with organosylane (NS-OS). Most active preparation for NC-PEIlaccase and NS-OS-laccase showed activities of 10.05 IU/g of support and 9.08 IU/g of support, respectively. The oligomerization of flavonoids was performed using immobilized laccase and obtained results were compared with those obtained with free laccase (same amount of activity units) as biocatalyst. Immobilized preparations showed promising activities in reaction of esculin oligomerization, since after 24h of reaction the conversions of 73.3% and 61.6% with NC-PEI-laccase and NS-OS-laccase, respectively was achieved, while the soluble enzyme gave the conversion of 92.4%. On the other hand, some lower activity of NC-PEI-laccase was observed in reaction of phloridzin oligomerization, since the achieved conversion was 43.3% compared to 80.7% of phloridzin conversion obtained with soluble laccase. The lower activity could be explained by different reaction medium, since, compared to the esculin oligomerization, the phloridzin oligomerization was performed in 30% methanol, due to its low water solubility. However, obtained results indicate that novel immobilized laccase preparations can be successfully applied in the production of various flavonoid oligomers.
PB  - Belgrade : University, Faculty of Geography
C3  - Book of Abstracts / International Scientific Conference Green Agenda for Western Balkans, Belgrade, June 20-22, 2023
T1  - Immobilization of laccase from Trametes versicolor on different nanocarriers and its application in the synthesis of flavonoid oligomers
SP  - 27
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6844
ER  - 

@conference{
author = "Vukoičić, Ana and Milivojević, Ana and Banjanac, Katarina and Petrov Ivanković, Anja and Ćorović, Marija and Marinković, Aleksandar and Palomo, Jose Miguel and Bezbradica, Dejan",
year = "2023",
abstract = "Flavonoids are a big class of plants’ secondary metabolites which possess antimicrobial, antioxidative, anti-inflammatory, etc. activities. However, their wider application is limited due to their poor solubility and stability in different environments. In order to overcome this problem and improve their biological and physicochemical characteristics, enzymatic oligomerization of flavonoids can be performed by using laccases as biocatalyst. In this study, laccase from Trametes versicolor was successfully immobilized onto two nanocarriers and used as a catalyst for the oligomerization of two flavonoids, esculin and phloridzin. For immobilization, nanocelulose prepared by ultrasonic treatment of commercial microcellulose and nanosilica from rice were used. Both carriers were modified in order to introduce amino groups on their surface: nanocelulose with poly(ethyleneimine) (NC-PEI) and nanosilica with organosylane (NS-OS). Most active preparation for NC-PEIlaccase and NS-OS-laccase showed activities of 10.05 IU/g of support and 9.08 IU/g of support, respectively. The oligomerization of flavonoids was performed using immobilized laccase and obtained results were compared with those obtained with free laccase (same amount of activity units) as biocatalyst. Immobilized preparations showed promising activities in reaction of esculin oligomerization, since after 24h of reaction the conversions of 73.3% and 61.6% with NC-PEI-laccase and NS-OS-laccase, respectively was achieved, while the soluble enzyme gave the conversion of 92.4%. On the other hand, some lower activity of NC-PEI-laccase was observed in reaction of phloridzin oligomerization, since the achieved conversion was 43.3% compared to 80.7% of phloridzin conversion obtained with soluble laccase. The lower activity could be explained by different reaction medium, since, compared to the esculin oligomerization, the phloridzin oligomerization was performed in 30% methanol, due to its low water solubility. However, obtained results indicate that novel immobilized laccase preparations can be successfully applied in the production of various flavonoid oligomers.",
publisher = "Belgrade : University, Faculty of Geography",
journal = "Book of Abstracts / International Scientific Conference Green Agenda for Western Balkans, Belgrade, June 20-22, 2023",
title = "Immobilization of laccase from Trametes versicolor on different nanocarriers and its application in the synthesis of flavonoid oligomers",
pages = "27",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6844"
}

Vukoičić, A., Milivojević, A., Banjanac, K., Petrov Ivanković, A., Ćorović, M., Marinković, A., Palomo, J. M.,& Bezbradica, D.. (2023). Immobilization of laccase from Trametes versicolor on different nanocarriers and its application in the synthesis of flavonoid oligomers. in Book of Abstracts / International Scientific Conference Green Agenda for Western Balkans, Belgrade, June 20-22, 2023
Belgrade : University, Faculty of Geography., 27.
https://hdl.handle.net/21.15107/rcub_technorep_6844

Vukoičić A, Milivojević A, Banjanac K, Petrov Ivanković A, Ćorović M, Marinković A, Palomo JM, Bezbradica D. Immobilization of laccase from Trametes versicolor on different nanocarriers and its application in the synthesis of flavonoid oligomers. in Book of Abstracts / International Scientific Conference Green Agenda for Western Balkans, Belgrade, June 20-22, 2023. 2023;:27.
https://hdl.handle.net/21.15107/rcub_technorep_6844 .

Vukoičić, Ana, Milivojević, Ana, Banjanac, Katarina, Petrov Ivanković, Anja, Ćorović, Marija, Marinković, Aleksandar, Palomo, Jose Miguel, Bezbradica, Dejan, "Immobilization of laccase from Trametes versicolor on different nanocarriers and its application in the synthesis of flavonoid oligomers" in Book of Abstracts / International Scientific Conference Green Agenda for Western Balkans, Belgrade, June 20-22, 2023 (2023):27,
https://hdl.handle.net/21.15107/rcub_technorep_6844 .

TY  - CONF
AU  - Veljković, Milica
AU  - Simović, Milica
AU  - Banjanac, Katarina
AU  - Milivojević, Ana
AU  - Ćorović, Marija
AU  - Vukoičić, Ana
AU  - Bezbradica, Dejan
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6843
AB  - With the increasing interest in functional products, prebiotics that selectively stimulate growth and activity of good bacteria in human gut, gained attention from both general and scientific community. The range of food products containing prebiotic oligosaccharides is rapidly expanding, causing their intensified production. Currently, there are a few recognized prebiotics, amongst which, fructo-oligosaccharides (FOS) proved to be particularly interesting owing to the confirmed positive effect on human wellbeing (restoring microbiota balance, improving immunity and lipid metabolism, enhancing vitamin production and calcium absorption) and exceptional physicochemical qualities. Namely, good taste quality, low sweetness, and low caloric value make them highly applicable supplement in food industry. Fructo-oligosaccharides are scarcely present in natural sources and nowadays are mainly produced by enzymatic conversion of sucrose and sucrose-rich substrates. Bearing in mind the complexity of synthesis process, resulting reaction mixture besides FOS (mixture of tri-, tetra- and pentasaccharides) contains significant portion of sucrose and monosaccharides. Within this study, efficient method for obtaining high-purity product upon sucrose conversion using fructosyltransferase (Pectinex® Ultra SP-L) was developed through detailed optimization of membrane separation processes. Under determined optimal conditions for nanofiltration (temperature of 35 °C, concentration of initial sugars of 3% and flow rate of 25 mL/min), undesired components (monosaccharides and partially sucrose) were removed from the initial mixture (58% FOS in total carbohydrates) and 1.48-fold increase the proportion of targeted bioactive components was achieved. Thus, product of high purity (86% FOS in total carbohydrates) was obtained with remarkable recovery yields of 90%. The prebiotic activity of the obtained product was confirmed in in vitro tests with several microbial cultures comprising representatives of beneficial (genera Lactobacillus and Saccharomyces) and pathogenic (Escherichia coli) gut microbiota. Having said that, it can be concluded that high-purity prebiotic product with great potential for application in different value-added food industry products was obtained.
PB  - Belgrade : University, Faculty of Geography
C3  - Book of Abstracts / International Scientific Conference Green Agenda for Western Balkans, Belgrade, June 20-22, 2023
T1  - Effective approach for obtaining high-purity prebiotics using membrane separation technology
SP  - 25
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6843
ER  - 

@conference{
author = "Veljković, Milica and Simović, Milica and Banjanac, Katarina and Milivojević, Ana and Ćorović, Marija and Vukoičić, Ana and Bezbradica, Dejan",
year = "2023",
abstract = "With the increasing interest in functional products, prebiotics that selectively stimulate growth and activity of good bacteria in human gut, gained attention from both general and scientific community. The range of food products containing prebiotic oligosaccharides is rapidly expanding, causing their intensified production. Currently, there are a few recognized prebiotics, amongst which, fructo-oligosaccharides (FOS) proved to be particularly interesting owing to the confirmed positive effect on human wellbeing (restoring microbiota balance, improving immunity and lipid metabolism, enhancing vitamin production and calcium absorption) and exceptional physicochemical qualities. Namely, good taste quality, low sweetness, and low caloric value make them highly applicable supplement in food industry. Fructo-oligosaccharides are scarcely present in natural sources and nowadays are mainly produced by enzymatic conversion of sucrose and sucrose-rich substrates. Bearing in mind the complexity of synthesis process, resulting reaction mixture besides FOS (mixture of tri-, tetra- and pentasaccharides) contains significant portion of sucrose and monosaccharides. Within this study, efficient method for obtaining high-purity product upon sucrose conversion using fructosyltransferase (Pectinex® Ultra SP-L) was developed through detailed optimization of membrane separation processes. Under determined optimal conditions for nanofiltration (temperature of 35 °C, concentration of initial sugars of 3% and flow rate of 25 mL/min), undesired components (monosaccharides and partially sucrose) were removed from the initial mixture (58% FOS in total carbohydrates) and 1.48-fold increase the proportion of targeted bioactive components was achieved. Thus, product of high purity (86% FOS in total carbohydrates) was obtained with remarkable recovery yields of 90%. The prebiotic activity of the obtained product was confirmed in in vitro tests with several microbial cultures comprising representatives of beneficial (genera Lactobacillus and Saccharomyces) and pathogenic (Escherichia coli) gut microbiota. Having said that, it can be concluded that high-purity prebiotic product with great potential for application in different value-added food industry products was obtained.",
publisher = "Belgrade : University, Faculty of Geography",
journal = "Book of Abstracts / International Scientific Conference Green Agenda for Western Balkans, Belgrade, June 20-22, 2023",
title = "Effective approach for obtaining high-purity prebiotics using membrane separation technology",
pages = "25",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6843"
}

Veljković, M., Simović, M., Banjanac, K., Milivojević, A., Ćorović, M., Vukoičić, A.,& Bezbradica, D.. (2023). Effective approach for obtaining high-purity prebiotics using membrane separation technology. in Book of Abstracts / International Scientific Conference Green Agenda for Western Balkans, Belgrade, June 20-22, 2023
Belgrade : University, Faculty of Geography., 25.
https://hdl.handle.net/21.15107/rcub_technorep_6843

Veljković M, Simović M, Banjanac K, Milivojević A, Ćorović M, Vukoičić A, Bezbradica D. Effective approach for obtaining high-purity prebiotics using membrane separation technology. in Book of Abstracts / International Scientific Conference Green Agenda for Western Balkans, Belgrade, June 20-22, 2023. 2023;:25.
https://hdl.handle.net/21.15107/rcub_technorep_6843 .

Veljković, Milica, Simović, Milica, Banjanac, Katarina, Milivojević, Ana, Ćorović, Marija, Vukoičić, Ana, Bezbradica, Dejan, "Effective approach for obtaining high-purity prebiotics using membrane separation technology" in Book of Abstracts / International Scientific Conference Green Agenda for Western Balkans, Belgrade, June 20-22, 2023 (2023):25,
https://hdl.handle.net/21.15107/rcub_technorep_6843 .

TY  - CONF
AU  - Veljković, Milica
AU  - Simović, Milica
AU  - Banjanac, Katarina
AU  - Petrov Ivanković, Anja
AU  - Nikolić, Valentina
AU  - Bezbradica, Dejan
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6842
AB  - Recently, there is an increasing interest in utilizing biomass and waste potential for development of new products and materials. The example of this is sunflower meal, by-product of sunflower seed oil industry, that is currently used as a cheap component of animal feed owing to a poor protein content. The major drawback for their application is high content of complex carbohydrates (15.27% hemicellulose, 12.54% cellulose and 5.88% lignin). Therefore, extraction and enzymatic transformation of carbohydrates (primarily xylan) represent an attractive valorization approach. Since xylan extraction from the plant cell wall is highly restricted by lignin presence, different alkaline extraction methods have been proposed. This work is focused on xylan extraction using ethanol extraction and subsequent delignification approach. The ethanol extraction step yielded fraction rich in simple sugars, polyphenols (predominantly chlorogenic acid) and colorants that proved to have great prebiotic potential for application in skin products enabling proliferation of beneficial skin commensal and suppressing the pathogen one. Introduction of additional delignification step enabled high xylan yields (91.35%). This fraction was subjected to the enzymatic treatment using commercial xylanase (ROHALASE® SEP-VISCO) to obtain xylo-oligosaccharides (XOS), compounds that comprise of 2–10 xylose residues linked via β-1,4-glycosidic bonds with high prebiotic activity and excellent application properties (high temperature and pH stability, good sweetening power and low caloric value) for food industry. As result of the sunflower meal xylan treatment under optimum reaction conditions (60°C, pH6 and enzyme concentration of 0.5% per substrate), XOS with a polymerization degree of 2–6 were produced (with predominance of XOS2), without xylose generation. The prebiotic activity of the obtained XOS fraction was confirmed by fermentation with beneficial microbial cultures and pathogenic gut microbiota representative. Therefore, it was shown that significant portion of meal can be converted to added-value functional ingredients, while remaining product retains higher protein content.
PB  - Belgrade : University, Faculty of Geography
C3  - Book of Abstracts / International Scientific Conference Green Agenda for Western Balkans, Belgrade, June 20-22, 2023
T1  - Valorization of sunflower meal toward the production of emerging prebiotics
SP  - 36
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6842
ER  - 

@conference{
author = "Veljković, Milica and Simović, Milica and Banjanac, Katarina and Petrov Ivanković, Anja and Nikolić, Valentina and Bezbradica, Dejan",
year = "2023",
abstract = "Recently, there is an increasing interest in utilizing biomass and waste potential for development of new products and materials. The example of this is sunflower meal, by-product of sunflower seed oil industry, that is currently used as a cheap component of animal feed owing to a poor protein content. The major drawback for their application is high content of complex carbohydrates (15.27% hemicellulose, 12.54% cellulose and 5.88% lignin). Therefore, extraction and enzymatic transformation of carbohydrates (primarily xylan) represent an attractive valorization approach. Since xylan extraction from the plant cell wall is highly restricted by lignin presence, different alkaline extraction methods have been proposed. This work is focused on xylan extraction using ethanol extraction and subsequent delignification approach. The ethanol extraction step yielded fraction rich in simple sugars, polyphenols (predominantly chlorogenic acid) and colorants that proved to have great prebiotic potential for application in skin products enabling proliferation of beneficial skin commensal and suppressing the pathogen one. Introduction of additional delignification step enabled high xylan yields (91.35%). This fraction was subjected to the enzymatic treatment using commercial xylanase (ROHALASE® SEP-VISCO) to obtain xylo-oligosaccharides (XOS), compounds that comprise of 2–10 xylose residues linked via β-1,4-glycosidic bonds with high prebiotic activity and excellent application properties (high temperature and pH stability, good sweetening power and low caloric value) for food industry. As result of the sunflower meal xylan treatment under optimum reaction conditions (60°C, pH6 and enzyme concentration of 0.5% per substrate), XOS with a polymerization degree of 2–6 were produced (with predominance of XOS2), without xylose generation. The prebiotic activity of the obtained XOS fraction was confirmed by fermentation with beneficial microbial cultures and pathogenic gut microbiota representative. Therefore, it was shown that significant portion of meal can be converted to added-value functional ingredients, while remaining product retains higher protein content.",
publisher = "Belgrade : University, Faculty of Geography",
journal = "Book of Abstracts / International Scientific Conference Green Agenda for Western Balkans, Belgrade, June 20-22, 2023",
title = "Valorization of sunflower meal toward the production of emerging prebiotics",
pages = "36",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6842"
}

Veljković, M., Simović, M., Banjanac, K., Petrov Ivanković, A., Nikolić, V.,& Bezbradica, D.. (2023). Valorization of sunflower meal toward the production of emerging prebiotics. in Book of Abstracts / International Scientific Conference Green Agenda for Western Balkans, Belgrade, June 20-22, 2023
Belgrade : University, Faculty of Geography., 36.
https://hdl.handle.net/21.15107/rcub_technorep_6842

Veljković M, Simović M, Banjanac K, Petrov Ivanković A, Nikolić V, Bezbradica D. Valorization of sunflower meal toward the production of emerging prebiotics. in Book of Abstracts / International Scientific Conference Green Agenda for Western Balkans, Belgrade, June 20-22, 2023. 2023;:36.
https://hdl.handle.net/21.15107/rcub_technorep_6842 .

Veljković, Milica, Simović, Milica, Banjanac, Katarina, Petrov Ivanković, Anja, Nikolić, Valentina, Bezbradica, Dejan, "Valorization of sunflower meal toward the production of emerging prebiotics" in Book of Abstracts / International Scientific Conference Green Agenda for Western Balkans, Belgrade, June 20-22, 2023 (2023):36,
https://hdl.handle.net/21.15107/rcub_technorep_6842 .