TY  - CONF
AU  - Lukić, Ivana
AU  - Milovanović, Stoja
AU  - Krgović, Nemanja
AU  - Tadić, Vanja
AU  - Tyśkiewicz, Katarzyna
AU  - Konkol, Marcin
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6907
AB  - Green tea is considered to be a plant with a variety of health benefits due to its antioxidative, antimicrobial,
anti-inflammatory, and anticancer activity. Besides the most important bioactive constituents, including
polyphenols, especially catechins, and flavonoids, green tea is rich in caffeine, and such complex composition
makes its extract suitable as a component of active food packaging or skin care systems [1,2]. The
technologies commonly proposed to obtain such materials involve some limitations, mainly related to the use
of liquid organic solvents that lead to low penetration of the active compound into the polymeric platform and,
consequently, limited loading efficiencies, non-unique dispersion, and solvent residue in the final material. An
excellent technique for direct loading of natural bioactive compounds from plant materials into polymeric
carriers that can overcome the aforementioned challenges is an integrated process accomplished by merging
supercritical fluid extraction (SFE) and supercritical solvent impregnation (SSI). Therefore, in this study, the
preparation of two types of polymer films and their functionalization with green tea leaf extract using the SFESSI
process was tested.
Starch/chitosan (SC) films were prepared by mixing the 1% chitosan solution with the 1% starch solution in a
mass ratio of 1:1, while starch/chitosan/β-cyclodextrin (SCCD) films were prepared by addition of 1% β-
cyclodextrin to starch and chitosan to obtain the ratio of 1:1:1. After solvent casting and drying at room
temperature, the films were additionally dried in an oven overnight at 35 °C. Initially, supercritical CO2
(scCO2) extraction was investigated as a method for isolating the extract from green tea at temperatures of 35
and 70 °C and pressure of 30 MPa, with and without the ethanol as a co-solvent. The obtained extraction yields
ranged from 0.91 to 4.22%, being the highest at a higher temperature. The chemical composition of the
obtained extracts was determined, as well as the total phenolic content (TPC), total flavonoid content (TFC),
total chlorophyll, and total carotenoid content. HPLC analysis revealed that caffeine was the major constituent
of all extracts with the amount ranging from 24.1 to 202.9 mg/g. The IC50 values determined using the DPPH
assay showed that the extract obtained at 35 °C with the addition of ethanol exhibited the strongest antioxidant
activity. After determining the SFE conditions that gave the green tea extract with high content of bioactive
compounds, prepared films were impregnated using the integrated SFE-SSI process for 4 h at the same
conditions as scCO2 extraction. The loading of green tea extracts onto films was up to 7.7% showing that lower
temperature (35 °C) and the addition of ethanol had a favourable influence. The presence of the extract on the
surface of impregnated samples was confirmed by FTIR analysis.
PB  - Budapest : University of Technology and Economics
C3  - Book of Abstract / 19th European Meeting on Supercritical Fluids, Budapest, Hungary, 21-24 May 2023
T1  - Selection of process conditions for the integrated process of supercritical CO2 extraction from green tea leaves and impregnation onto polymer films
SP  - 124
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6907
ER  - 

@conference{
author = "Lukić, Ivana and Milovanović, Stoja and Krgović, Nemanja and Tadić, Vanja and Tyśkiewicz, Katarzyna and Konkol, Marcin",
year = "2023",
abstract = "Green tea is considered to be a plant with a variety of health benefits due to its antioxidative, antimicrobial,
anti-inflammatory, and anticancer activity. Besides the most important bioactive constituents, including
polyphenols, especially catechins, and flavonoids, green tea is rich in caffeine, and such complex composition
makes its extract suitable as a component of active food packaging or skin care systems [1,2]. The
technologies commonly proposed to obtain such materials involve some limitations, mainly related to the use
of liquid organic solvents that lead to low penetration of the active compound into the polymeric platform and,
consequently, limited loading efficiencies, non-unique dispersion, and solvent residue in the final material. An
excellent technique for direct loading of natural bioactive compounds from plant materials into polymeric
carriers that can overcome the aforementioned challenges is an integrated process accomplished by merging
supercritical fluid extraction (SFE) and supercritical solvent impregnation (SSI). Therefore, in this study, the
preparation of two types of polymer films and their functionalization with green tea leaf extract using the SFESSI
process was tested.
Starch/chitosan (SC) films were prepared by mixing the 1% chitosan solution with the 1% starch solution in a
mass ratio of 1:1, while starch/chitosan/β-cyclodextrin (SCCD) films were prepared by addition of 1% β-
cyclodextrin to starch and chitosan to obtain the ratio of 1:1:1. After solvent casting and drying at room
temperature, the films were additionally dried in an oven overnight at 35 °C. Initially, supercritical CO2
(scCO2) extraction was investigated as a method for isolating the extract from green tea at temperatures of 35
and 70 °C and pressure of 30 MPa, with and without the ethanol as a co-solvent. The obtained extraction yields
ranged from 0.91 to 4.22%, being the highest at a higher temperature. The chemical composition of the
obtained extracts was determined, as well as the total phenolic content (TPC), total flavonoid content (TFC),
total chlorophyll, and total carotenoid content. HPLC analysis revealed that caffeine was the major constituent
of all extracts with the amount ranging from 24.1 to 202.9 mg/g. The IC50 values determined using the DPPH
assay showed that the extract obtained at 35 °C with the addition of ethanol exhibited the strongest antioxidant
activity. After determining the SFE conditions that gave the green tea extract with high content of bioactive
compounds, prepared films were impregnated using the integrated SFE-SSI process for 4 h at the same
conditions as scCO2 extraction. The loading of green tea extracts onto films was up to 7.7% showing that lower
temperature (35 °C) and the addition of ethanol had a favourable influence. The presence of the extract on the
surface of impregnated samples was confirmed by FTIR analysis.",
publisher = "Budapest : University of Technology and Economics",
journal = "Book of Abstract / 19th European Meeting on Supercritical Fluids, Budapest, Hungary, 21-24 May 2023",
title = "Selection of process conditions for the integrated process of supercritical CO2 extraction from green tea leaves and impregnation onto polymer films",
pages = "124",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6907"
}

Lukić, I., Milovanović, S., Krgović, N., Tadić, V., Tyśkiewicz, K.,& Konkol, M.. (2023). Selection of process conditions for the integrated process of supercritical CO2 extraction from green tea leaves and impregnation onto polymer films. in Book of Abstract / 19th European Meeting on Supercritical Fluids, Budapest, Hungary, 21-24 May 2023
Budapest : University of Technology and Economics., 124.
https://hdl.handle.net/21.15107/rcub_technorep_6907

Lukić I, Milovanović S, Krgović N, Tadić V, Tyśkiewicz K, Konkol M. Selection of process conditions for the integrated process of supercritical CO2 extraction from green tea leaves and impregnation onto polymer films. in Book of Abstract / 19th European Meeting on Supercritical Fluids, Budapest, Hungary, 21-24 May 2023. 2023;:124.
https://hdl.handle.net/21.15107/rcub_technorep_6907 .

Lukić, Ivana, Milovanović, Stoja, Krgović, Nemanja, Tadić, Vanja, Tyśkiewicz, Katarzyna, Konkol, Marcin, "Selection of process conditions for the integrated process of supercritical CO2 extraction from green tea leaves and impregnation onto polymer films" in Book of Abstract / 19th European Meeting on Supercritical Fluids, Budapest, Hungary, 21-24 May 2023 (2023):124,
https://hdl.handle.net/21.15107/rcub_technorep_6907 .

TY  - CONF
AU  - Milovanović, Stoja
AU  - Tyśkiewicz, Katarzyna
AU  - Konkol, Marcin
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6906
AB  - Interest in the separation of green tea extracts continues to grow due to its significant bioactivity, wide
applicability as well as a large number of green tea spices, variety of extraction techniques, and lack of
systematic data. The present early stage work was intended to estimate the effect of temperature and co-solvent
addition on an amount of separated constituents from green tea (gunpowder tea variety, China) during the
supercritical carbon dioxide (sc-CO2) extraction process.
For this purpose, the temperature of the supercritical extraction process was increased up to 90 °C at a constant
pressure of 30 MPa. After the selection of appropriate conditions, co-solvents (ethanol, ethanol/water, and
water) were added to sc-CO2. Obtained extracts were analyzed regarding total phenolic content (TPC), total
flavonoid content (TFC), DPPH radical scavenging activity, total chlorophyll, and total carotenoid content.
The results of the supercritical extraction process were compared with the conventional extraction process
(extraction using Soxhlet apparatus).
The results showed that a linear decrease in the density of neat sc-CO2 led to a linear increase in extraction
yields up to 5.5%. The addition of co-solvents had a variable effect on the amount of separated extracts. While
it increased extraction yields at a lower temperature, it decreased extraction yields at a higher temperature.
An increase in temperature for the extraction process with neat sc-
CO2 also decreased TPC, TFC, chlorophylls, and carotenoids
content. The addition of co-solvents to sc-CO2 increased amounts
of tested compounds in obtained extracts. It was interesting to
notice a decrease in the amount of tested compounds with an
increase in water content during extractions. The highest values of
TPC and TFC detected were 136.5 mg GAE/g and 40.7 mg QE/g,
respectively. Extract solutions with a concentration of 20 mg/mL
inhibited up to 65% of DPPH radical. Chlorophyll A, chlorophyll
B, and carotenoids were detected in amounts up to 8.1 g/kg,
0.7 g/kg, and 0.5 g/kg of dry extract, respectively. Extracts
obtained by conventional extraction contained higher amounts of
TPC and TFC. On the other hand, those extracts contained lower
amounts of total chlorophylls and carotenoids.
Although supercritical extraction processes from green tea leaves have been performed for decades and its
industrial application is present, there are still many unknowns. To the best of our knowledge, this is the first
report in available literature on chlorophyll and carotenoid contents in supercritical extracts from green tea.
Also tested process parameters enabled the achievement of higher yields (for neat sc-CO2) as well as higher
TPC compared with previously reported ones for green tea supercritical extracts. Chemical analysis of obtained
extracts is pending.
PB  - Budapest : University of Technology and Economics
C3  - Book of Abstract / 19th European Meeting on Supercritical Fluids, Budapest, Hungary, 21-24 May 2023
T1  - Influence of supercritical carbon dioxide extraction process temperature and co-solvent addition on the quality of green tea leaves extracts
SP  - 123
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6906
ER  - 

@conference{
author = "Milovanović, Stoja and Tyśkiewicz, Katarzyna and Konkol, Marcin",
year = "2023",
abstract = "Interest in the separation of green tea extracts continues to grow due to its significant bioactivity, wide
applicability as well as a large number of green tea spices, variety of extraction techniques, and lack of
systematic data. The present early stage work was intended to estimate the effect of temperature and co-solvent
addition on an amount of separated constituents from green tea (gunpowder tea variety, China) during the
supercritical carbon dioxide (sc-CO2) extraction process.
For this purpose, the temperature of the supercritical extraction process was increased up to 90 °C at a constant
pressure of 30 MPa. After the selection of appropriate conditions, co-solvents (ethanol, ethanol/water, and
water) were added to sc-CO2. Obtained extracts were analyzed regarding total phenolic content (TPC), total
flavonoid content (TFC), DPPH radical scavenging activity, total chlorophyll, and total carotenoid content.
The results of the supercritical extraction process were compared with the conventional extraction process
(extraction using Soxhlet apparatus).
The results showed that a linear decrease in the density of neat sc-CO2 led to a linear increase in extraction
yields up to 5.5%. The addition of co-solvents had a variable effect on the amount of separated extracts. While
it increased extraction yields at a lower temperature, it decreased extraction yields at a higher temperature.
An increase in temperature for the extraction process with neat sc-
CO2 also decreased TPC, TFC, chlorophylls, and carotenoids
content. The addition of co-solvents to sc-CO2 increased amounts
of tested compounds in obtained extracts. It was interesting to
notice a decrease in the amount of tested compounds with an
increase in water content during extractions. The highest values of
TPC and TFC detected were 136.5 mg GAE/g and 40.7 mg QE/g,
respectively. Extract solutions with a concentration of 20 mg/mL
inhibited up to 65% of DPPH radical. Chlorophyll A, chlorophyll
B, and carotenoids were detected in amounts up to 8.1 g/kg,
0.7 g/kg, and 0.5 g/kg of dry extract, respectively. Extracts
obtained by conventional extraction contained higher amounts of
TPC and TFC. On the other hand, those extracts contained lower
amounts of total chlorophylls and carotenoids.
Although supercritical extraction processes from green tea leaves have been performed for decades and its
industrial application is present, there are still many unknowns. To the best of our knowledge, this is the first
report in available literature on chlorophyll and carotenoid contents in supercritical extracts from green tea.
Also tested process parameters enabled the achievement of higher yields (for neat sc-CO2) as well as higher
TPC compared with previously reported ones for green tea supercritical extracts. Chemical analysis of obtained
extracts is pending.",
publisher = "Budapest : University of Technology and Economics",
journal = "Book of Abstract / 19th European Meeting on Supercritical Fluids, Budapest, Hungary, 21-24 May 2023",
title = "Influence of supercritical carbon dioxide extraction process temperature and co-solvent addition on the quality of green tea leaves extracts",
pages = "123",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6906"
}

Milovanović, S., Tyśkiewicz, K.,& Konkol, M.. (2023). Influence of supercritical carbon dioxide extraction process temperature and co-solvent addition on the quality of green tea leaves extracts. in Book of Abstract / 19th European Meeting on Supercritical Fluids, Budapest, Hungary, 21-24 May 2023
Budapest : University of Technology and Economics., 123.
https://hdl.handle.net/21.15107/rcub_technorep_6906

Milovanović S, Tyśkiewicz K, Konkol M. Influence of supercritical carbon dioxide extraction process temperature and co-solvent addition on the quality of green tea leaves extracts. in Book of Abstract / 19th European Meeting on Supercritical Fluids, Budapest, Hungary, 21-24 May 2023. 2023;:123.
https://hdl.handle.net/21.15107/rcub_technorep_6906 .

Milovanović, Stoja, Tyśkiewicz, Katarzyna, Konkol, Marcin, "Influence of supercritical carbon dioxide extraction process temperature and co-solvent addition on the quality of green tea leaves extracts" in Book of Abstract / 19th European Meeting on Supercritical Fluids, Budapest, Hungary, 21-24 May 2023 (2023):123,
https://hdl.handle.net/21.15107/rcub_technorep_6906 .