Roxana Elena Ionete - Academia.edu (original) (raw)
Papers by Roxana Elena Ionete
Separations
Grapes are rich in phenolic compounds, being important for human health with anti-inflammatory, a... more Grapes are rich in phenolic compounds, being important for human health with anti-inflammatory, antiatherosclerotic, antimutagenic, anticarcinogenic, antibacterial, antiviral, and antimicrobial activity. The winemaking of the grapes generates significant amounts of waste. These wastes contain bioactive compounds in their biomass that can be used as a source of food improvement or as a source of nutrition supplementation. This study looks at the content of bioactive compounds, the polyphenolic profile, and the antioxidant activity in different white and red grape pomaces. The investigation of bioactive characteristics (total polyphenols, total flavonoids, catechins, tannins, and antioxidant activity) was carried out by UV-Vis spectrophotometric methods, while the individual polyphenolic composition was investigated by target and screening UHPLC-HRMS/MS analysis. Principal components (PCA) and the heat maps analysis allows the discrimination between the grape pomace resulted from whit...
Progress of Cryogenics and Isotopes Separation, 2019
Progress of Cryogenics and Isotopes Separation, Nov 20, 2019
Progress of Cryogenics and Isotopes Separation, 2019
Materials
The capitalization of agri-food waste is essential for the sustainability of a circular economy. ... more The capitalization of agri-food waste is essential for the sustainability of a circular economy. This work focuses on a solution to eliminate such waste, meat and bone meal (MBM), which is produced in large quantities by the food industry and is prohibited for use as animal feed under the European directives. Therefore, with the focus of converting waste to energy, the catalytic pyrolysis of MBM in the presence of mesoporous silica nanocatalysts (SBA-3 and SBA-16 materials and metallic derivates) was investigated in a home-made reactor for the production of renewable energy. The mesoporous silica materials were synthesized using relatively simple methods and then characterized in order to determine their morpho-structural characteristics. The MBM pyrolysis behavior under different experimental conditions was examined in detail, both in the presence and absence of the new catalysts. The resulting MBM-based pyrolysis products, MBMPYOILs and MBMPYGASs, were also assessed as potential a...
Atmosphere
Mitigating climate change is a challenge that urgently needs to be addressed, as it has an increa... more Mitigating climate change is a challenge that urgently needs to be addressed, as it has an increasing impact on the planet. According to the latest reports, global CO2 emissions must be neutralized by 2050 in order to limit the rise in temperature to 1.5 °C. This work presents the evolution of Land Use, Land Use Change and Forestry (LULUCF) greenhouse gas (GHG) emissions/removals at the EU-27 + UK level for the 1990–2019 time period, as well as LULUCF emissions/removals forecasts for Romania up to 2040. The results revealed a 23% reduction in GHG emissions for the EU-27 + UK in 2019 compared to 1990. Romania’s yearly average of GHG emissions/removals was 28,000 kt CO2 eq., representing roughly 9.7% of the EU’s annual average. In terms of projections for Romania, the only scenario that will not be in the target set by the new LULUCF Regulation is WEM (Reference Scenario/With Existing Measures), in which net GHG removals will be reduced by approximately 218 kt CO2 eq., or 0.9 percent,...
Plants
In this work, the challenges and progression in stable isotope investigation, from the analytical... more In this work, the challenges and progression in stable isotope investigation, from the analytical tools and technical sample preparation procedures to the dendroclimatological experiments, were reviewed in terms of their use to assess tree physiological responses to environmental changes. Since the isotope signature of whole wood is not always a reliable tool in studying the climate changes, cellulose is often preferred as the study material in paleoclimatic studies. Nevertheless, the isotope analysis of cellulose is challenging due to the difficulty to remove the other wood components (extractives, lignin, pectin, and hemicelluloses). Additionally, in the case of hydrogen isotope analysis, about 30% of the hydrogen atoms of cellulose are exchanged with the surrounding water, which complicates the isotope analysis. In recent years, more automated isotope analysis methods were developed based on high temperature pyrolysis of cellulose, followed by the chromatographic separation of H2...
Nutrients
Natural ecosystems are polluted with various contaminants, and among these heavy metals raise con... more Natural ecosystems are polluted with various contaminants, and among these heavy metals raise concerns due to their side effects on both environment and human health. An investigation was conducted on essential oil samples, comparing similar products between seven producers, and the results indicated a wide variation of metal content. The recommended limits imposed by European Union regulations for medicinal plants are exceeded only in Mentha × pipperita (Adams, 0.61 mg/kg). Except for Thymus vulgaris, the multivariate analysis showed a strong correlation between toxic and microelements (p < 0.001). We verified plant species–specific bioaccumulation patterns with non-metric multidimensional scaling analysis. The model showed that Adams, Doterra, Hypericum, and Steaua Divina essential oils originated from plants containing high micro and macroelement (Cu, Mn, Mg, Na) levels. We noted that the cancer risk values for Ni were the highest (2.02 × 10−9–7.89 × 10−7). Based on the target...
Progress of Cryogenics and Isotopes Separation, 2014
Progress of Cryogenics and Isotopes Separation, 2014
Grapes and Wines - Advances in Production, Processing, Analysis and Valorization, 2018
Polyphenols play an important role in the quality of wines, due to their contribution to the wine... more Polyphenols play an important role in the quality of wines, due to their contribution to the wine sensory properties: color, astringency and bitterness. They act as antioxidants, having positive role in human health. They can be divided into non-flavonoid (hydroxybenzoic and hydroxycinnamic acids and stilbenes) and flavonoid compounds (anthocyanins, flavan-3-ols and flavonols). Anthocyanins are responsible for the color of red grapes and wines, hydroxycinnamic and hydroxybenzoic acids act as copigments, stilbenes as antioxidants and the flavan-3-ols are mainly responsible for the astringency, bitterness and structure of wines, being involved also in the color stabilization during aging. This chapter will focus on the chemical structures of the main polyphenols, their identification and quantification in grapes and wines by advanced analytical techniques, highlighting also the maceration and aging impact on the polyphenols evolution. The factors influencing the phenolic accumulation in grapes are also reviewed, emphasizing as well the relationship between phenolic content in grapes versus wine. Polyphenolic changes during the wine making process are highlighted along with the main polyphenol extraction methods and analysis techniques. This research will contribute to the improvement in the knowledge of polyphenols: their presence in grapes, the relationship with wine quality and the influence of the external factors on their evolution.
World Academy of Science, Engineering and Technology, International Journal of Nutrition and Food Engineering, 2016
<p>Ascunsă cave (Romania) is the subject of a monitoring program since 2012. While... more <p>Ascunsă cave (Romania) is the subject of a monitoring program since 2012. While the cave air temperature was very stable around 7°C for most of the time, it experienced in 2019 a 3°C rise, and remained high until the present.</p><p>We present here δ<sup>18</sup>O, δ<sup>13</sup>C, and clumped isotope results from calcite farmed at two drip points inside the cave (POM X and POM 2). POM X has a slower drip rate than POM 2 and deposits calcite more continuously. Calcite deposition has been shown to depend on cave air CO<sub>2</sub> concentration, which controls the drip water pH and, further, the calcite saturation index.</p><p>In 2019, δ<sup>18</sup>O values at both sites quickly shifted to lower values as a response to the increase in temperature. At POM X, values were situated between approximately -7.2‰ and -7.6‰ before this transition, whereas in 2019 they shifted to -7.8‰ - -8.0‰. At POM 2, where values were generally lower, they shifted from -7.5‰ to -7.8‰ to -8.0‰.</p><p>Clumped isotope temperature estimates mostly agree, within measurement error, with measured cave temperature. This agreement is notable given that strong offsets are commonly observed in mid-latitude caves, reflecting kinetic fractionation effects. However, intervals with deviations from cave temperature are also observed, suggesting variations in isotopic disequilibrium conditions with time.</p><p>Here we will discuss these isotope changes in relation to cave air temperature and CO<sub>2</sub> concentration, drip water isotope values and elemental chemistry, as well as in relation to drip rates, in order to improve our understanding of calcite precipitation and isotope effects in caves.</p>
Advances in environmental engineering and green technologies book series, Mar 11, 2022
International Journal of Multidisciplinary Research and Analysis, 2022
Determination of heavy metals in soil and wine is very important for wine quality and consumer he... more Determination of heavy metals in soil and wine is very important for wine quality and consumer health, but at the same time it is a complementary tool for differentiating wines according to their geographical origin. In this work, soils and ten brands of wines originated from four major wine-growing areas of Romania (Iaşi, Babadag, Ştefăneşti and Blaj) were considered for performing a multielement (Cr, Ni, Cu, As, Pb, Hg, V, Sr, Mn, Zn, Fe) investigation in order to assess regional specificity. Heavy metals found in the investigated wines were below the limits imposed by European standards (O.I.V.) the elements concentrations following the trend: Zn>Fe>Mn>Sr>Ni>Cr>Cu>Pb>V>Hg>As. For the soils analyzed, the heavy metals content was found to be below the maximum permitted limit, except for Cu (135.45 mg/kg) from the Iaşi vineyard, which was at the permitted limit. The high values obtained for copper may be the result of different treatments with the Borde...
Progress of Cryogenics and Isotopes Separation, 2009
Forests, 2022
Drought-induced dieback has been extensively studied in various forests habitats. We used a retro... more Drought-induced dieback has been extensively studied in various forests habitats. We used a retrospective tree ring width (TRW), basal area increment (BAI), oxygen isotope ratios in tree ring cellulose (δ18OTR) and carbon isotope ratios in tree ring cellulose (δ13CTR) to assess causes in declining Pinus sylvestris L. and Pinus nigra J.F. Arnold. The climate data analysis indicates a significant increased trend occurred after 1980 in minimum, mean and maximum temperature and a reduced amount of precipitation compared to the 1920–1980-time scale. According to the Palmer Drought Severity Index, we found two extreme drought years (1946 and 2000) and three years with severe drought (1990, 2003 and 2012). One-way ANOVA indicated no significant difference between P. nigra and P sylvestris tree ring width, basal area increment, but a considerable difference between δ13CTR and δ18OTR. Basal area increment evaluated the climate-growth relationship most accurately, comparing to δ18OTR and δ13C...
Scientific Reports, 2022
Heavy metal pollution of river freshwater environments currently raises significant concerns due ... more Heavy metal pollution of river freshwater environments currently raises significant concerns due to the toxic effects and the fact that heavy metal behavior is not fully understood. This study assessed the contamination level of eight heavy metals and trace elements (Cr, Ni, Cu, Zn, As, Pb, Cd, and Hg) in the surface sediments of 19 sites in 2018 during four periods (March, May, June, and October) in Olt River sediments. Multivariate statistical techniques were used, namely, one-way ANOVA, person product-moment correlation analysis, principal component analysis, hierarchical cluster analysis, and sediment quality indicators such as the contamination factor and pollution load index. The results demonstrated higher contents of Ni, Cu, Zn, As, Pb, Cd, and Hg, with values that were over 2.46, 4.40, 1.15, 8.28, 1.10, 1.53, and 3.71 times more, respectively, compared with the national quality standards for sediments. We observed a positive significant statistical correlation (p < 0.001...
Separations
Grapes are rich in phenolic compounds, being important for human health with anti-inflammatory, a... more Grapes are rich in phenolic compounds, being important for human health with anti-inflammatory, antiatherosclerotic, antimutagenic, anticarcinogenic, antibacterial, antiviral, and antimicrobial activity. The winemaking of the grapes generates significant amounts of waste. These wastes contain bioactive compounds in their biomass that can be used as a source of food improvement or as a source of nutrition supplementation. This study looks at the content of bioactive compounds, the polyphenolic profile, and the antioxidant activity in different white and red grape pomaces. The investigation of bioactive characteristics (total polyphenols, total flavonoids, catechins, tannins, and antioxidant activity) was carried out by UV-Vis spectrophotometric methods, while the individual polyphenolic composition was investigated by target and screening UHPLC-HRMS/MS analysis. Principal components (PCA) and the heat maps analysis allows the discrimination between the grape pomace resulted from whit...
Progress of Cryogenics and Isotopes Separation, 2019
Progress of Cryogenics and Isotopes Separation, Nov 20, 2019
Progress of Cryogenics and Isotopes Separation, 2019
Materials
The capitalization of agri-food waste is essential for the sustainability of a circular economy. ... more The capitalization of agri-food waste is essential for the sustainability of a circular economy. This work focuses on a solution to eliminate such waste, meat and bone meal (MBM), which is produced in large quantities by the food industry and is prohibited for use as animal feed under the European directives. Therefore, with the focus of converting waste to energy, the catalytic pyrolysis of MBM in the presence of mesoporous silica nanocatalysts (SBA-3 and SBA-16 materials and metallic derivates) was investigated in a home-made reactor for the production of renewable energy. The mesoporous silica materials were synthesized using relatively simple methods and then characterized in order to determine their morpho-structural characteristics. The MBM pyrolysis behavior under different experimental conditions was examined in detail, both in the presence and absence of the new catalysts. The resulting MBM-based pyrolysis products, MBMPYOILs and MBMPYGASs, were also assessed as potential a...
Atmosphere
Mitigating climate change is a challenge that urgently needs to be addressed, as it has an increa... more Mitigating climate change is a challenge that urgently needs to be addressed, as it has an increasing impact on the planet. According to the latest reports, global CO2 emissions must be neutralized by 2050 in order to limit the rise in temperature to 1.5 °C. This work presents the evolution of Land Use, Land Use Change and Forestry (LULUCF) greenhouse gas (GHG) emissions/removals at the EU-27 + UK level for the 1990–2019 time period, as well as LULUCF emissions/removals forecasts for Romania up to 2040. The results revealed a 23% reduction in GHG emissions for the EU-27 + UK in 2019 compared to 1990. Romania’s yearly average of GHG emissions/removals was 28,000 kt CO2 eq., representing roughly 9.7% of the EU’s annual average. In terms of projections for Romania, the only scenario that will not be in the target set by the new LULUCF Regulation is WEM (Reference Scenario/With Existing Measures), in which net GHG removals will be reduced by approximately 218 kt CO2 eq., or 0.9 percent,...
Plants
In this work, the challenges and progression in stable isotope investigation, from the analytical... more In this work, the challenges and progression in stable isotope investigation, from the analytical tools and technical sample preparation procedures to the dendroclimatological experiments, were reviewed in terms of their use to assess tree physiological responses to environmental changes. Since the isotope signature of whole wood is not always a reliable tool in studying the climate changes, cellulose is often preferred as the study material in paleoclimatic studies. Nevertheless, the isotope analysis of cellulose is challenging due to the difficulty to remove the other wood components (extractives, lignin, pectin, and hemicelluloses). Additionally, in the case of hydrogen isotope analysis, about 30% of the hydrogen atoms of cellulose are exchanged with the surrounding water, which complicates the isotope analysis. In recent years, more automated isotope analysis methods were developed based on high temperature pyrolysis of cellulose, followed by the chromatographic separation of H2...
Nutrients
Natural ecosystems are polluted with various contaminants, and among these heavy metals raise con... more Natural ecosystems are polluted with various contaminants, and among these heavy metals raise concerns due to their side effects on both environment and human health. An investigation was conducted on essential oil samples, comparing similar products between seven producers, and the results indicated a wide variation of metal content. The recommended limits imposed by European Union regulations for medicinal plants are exceeded only in Mentha × pipperita (Adams, 0.61 mg/kg). Except for Thymus vulgaris, the multivariate analysis showed a strong correlation between toxic and microelements (p < 0.001). We verified plant species–specific bioaccumulation patterns with non-metric multidimensional scaling analysis. The model showed that Adams, Doterra, Hypericum, and Steaua Divina essential oils originated from plants containing high micro and macroelement (Cu, Mn, Mg, Na) levels. We noted that the cancer risk values for Ni were the highest (2.02 × 10−9–7.89 × 10−7). Based on the target...
Progress of Cryogenics and Isotopes Separation, 2014
Progress of Cryogenics and Isotopes Separation, 2014
Grapes and Wines - Advances in Production, Processing, Analysis and Valorization, 2018
Polyphenols play an important role in the quality of wines, due to their contribution to the wine... more Polyphenols play an important role in the quality of wines, due to their contribution to the wine sensory properties: color, astringency and bitterness. They act as antioxidants, having positive role in human health. They can be divided into non-flavonoid (hydroxybenzoic and hydroxycinnamic acids and stilbenes) and flavonoid compounds (anthocyanins, flavan-3-ols and flavonols). Anthocyanins are responsible for the color of red grapes and wines, hydroxycinnamic and hydroxybenzoic acids act as copigments, stilbenes as antioxidants and the flavan-3-ols are mainly responsible for the astringency, bitterness and structure of wines, being involved also in the color stabilization during aging. This chapter will focus on the chemical structures of the main polyphenols, their identification and quantification in grapes and wines by advanced analytical techniques, highlighting also the maceration and aging impact on the polyphenols evolution. The factors influencing the phenolic accumulation in grapes are also reviewed, emphasizing as well the relationship between phenolic content in grapes versus wine. Polyphenolic changes during the wine making process are highlighted along with the main polyphenol extraction methods and analysis techniques. This research will contribute to the improvement in the knowledge of polyphenols: their presence in grapes, the relationship with wine quality and the influence of the external factors on their evolution.
World Academy of Science, Engineering and Technology, International Journal of Nutrition and Food Engineering, 2016
<p>Ascunsă cave (Romania) is the subject of a monitoring program since 2012. While... more <p>Ascunsă cave (Romania) is the subject of a monitoring program since 2012. While the cave air temperature was very stable around 7°C for most of the time, it experienced in 2019 a 3°C rise, and remained high until the present.</p><p>We present here δ<sup>18</sup>O, δ<sup>13</sup>C, and clumped isotope results from calcite farmed at two drip points inside the cave (POM X and POM 2). POM X has a slower drip rate than POM 2 and deposits calcite more continuously. Calcite deposition has been shown to depend on cave air CO<sub>2</sub> concentration, which controls the drip water pH and, further, the calcite saturation index.</p><p>In 2019, δ<sup>18</sup>O values at both sites quickly shifted to lower values as a response to the increase in temperature. At POM X, values were situated between approximately -7.2‰ and -7.6‰ before this transition, whereas in 2019 they shifted to -7.8‰ - -8.0‰. At POM 2, where values were generally lower, they shifted from -7.5‰ to -7.8‰ to -8.0‰.</p><p>Clumped isotope temperature estimates mostly agree, within measurement error, with measured cave temperature. This agreement is notable given that strong offsets are commonly observed in mid-latitude caves, reflecting kinetic fractionation effects. However, intervals with deviations from cave temperature are also observed, suggesting variations in isotopic disequilibrium conditions with time.</p><p>Here we will discuss these isotope changes in relation to cave air temperature and CO<sub>2</sub> concentration, drip water isotope values and elemental chemistry, as well as in relation to drip rates, in order to improve our understanding of calcite precipitation and isotope effects in caves.</p>
Advances in environmental engineering and green technologies book series, Mar 11, 2022
International Journal of Multidisciplinary Research and Analysis, 2022
Determination of heavy metals in soil and wine is very important for wine quality and consumer he... more Determination of heavy metals in soil and wine is very important for wine quality and consumer health, but at the same time it is a complementary tool for differentiating wines according to their geographical origin. In this work, soils and ten brands of wines originated from four major wine-growing areas of Romania (Iaşi, Babadag, Ştefăneşti and Blaj) were considered for performing a multielement (Cr, Ni, Cu, As, Pb, Hg, V, Sr, Mn, Zn, Fe) investigation in order to assess regional specificity. Heavy metals found in the investigated wines were below the limits imposed by European standards (O.I.V.) the elements concentrations following the trend: Zn>Fe>Mn>Sr>Ni>Cr>Cu>Pb>V>Hg>As. For the soils analyzed, the heavy metals content was found to be below the maximum permitted limit, except for Cu (135.45 mg/kg) from the Iaşi vineyard, which was at the permitted limit. The high values obtained for copper may be the result of different treatments with the Borde...
Progress of Cryogenics and Isotopes Separation, 2009
Forests, 2022
Drought-induced dieback has been extensively studied in various forests habitats. We used a retro... more Drought-induced dieback has been extensively studied in various forests habitats. We used a retrospective tree ring width (TRW), basal area increment (BAI), oxygen isotope ratios in tree ring cellulose (δ18OTR) and carbon isotope ratios in tree ring cellulose (δ13CTR) to assess causes in declining Pinus sylvestris L. and Pinus nigra J.F. Arnold. The climate data analysis indicates a significant increased trend occurred after 1980 in minimum, mean and maximum temperature and a reduced amount of precipitation compared to the 1920–1980-time scale. According to the Palmer Drought Severity Index, we found two extreme drought years (1946 and 2000) and three years with severe drought (1990, 2003 and 2012). One-way ANOVA indicated no significant difference between P. nigra and P sylvestris tree ring width, basal area increment, but a considerable difference between δ13CTR and δ18OTR. Basal area increment evaluated the climate-growth relationship most accurately, comparing to δ18OTR and δ13C...
Scientific Reports, 2022
Heavy metal pollution of river freshwater environments currently raises significant concerns due ... more Heavy metal pollution of river freshwater environments currently raises significant concerns due to the toxic effects and the fact that heavy metal behavior is not fully understood. This study assessed the contamination level of eight heavy metals and trace elements (Cr, Ni, Cu, Zn, As, Pb, Cd, and Hg) in the surface sediments of 19 sites in 2018 during four periods (March, May, June, and October) in Olt River sediments. Multivariate statistical techniques were used, namely, one-way ANOVA, person product-moment correlation analysis, principal component analysis, hierarchical cluster analysis, and sediment quality indicators such as the contamination factor and pollution load index. The results demonstrated higher contents of Ni, Cu, Zn, As, Pb, Cd, and Hg, with values that were over 2.46, 4.40, 1.15, 8.28, 1.10, 1.53, and 3.71 times more, respectively, compared with the national quality standards for sediments. We observed a positive significant statistical correlation (p < 0.001...