DOAJ (DOAJ: Directory of Open Access Journals), Jun 1, 2012
Coconut fat could be an important source of bioactive compounds with a large applicability in ind... more Coconut fat could be an important source of bioactive compounds with a large applicability in industry. In this study it was realized the enzymatic hydrolysis of coconut fat with different yeast strains of Yarrowia lipolytica. The aim of this study was to optimize the hydrolysis conditions and determination of Yarrowia lipolytica specificity on coconut fat as substrate. The hydrolysis was performed by yeast strains cultivated on stationary solid state conditions on spirit blue agar medium supplemented with 3% coconut fat, at 25°C and 4°C, and at values of water activity of 0.98, 0.96 and 0.93. The substrate hydrolysis index was recorded every 24 hours, during of 240 hours of stationary cultivation. The most active lipolytic yeast was strain coded S5 which produce a high level of extracellular lipase with high coconut hydrolyze activity at 25°C and two water activities 0.98 and 0.96, in the shortest time (24 – 72 hours). In the presence of 3% NaCl in media, the strains coded S9, S5 and S4 were the most active from all tested strains at 25°C and 4°C. At low temperatures and in presence of 10.1% NaCl all tested yeasts had no lipolytic activity.
Using a Central Composite Design, the extraction of bioactive compounds from red grape Băbească n... more Using a Central Composite Design, the extraction of bioactive compounds from red grape Băbească neagră peels was optimized by applying a conventional solvent extraction. On the anthocyanin content, total phenolic content, and antioxidant activity (using the DPPH method), the effects of extraction factors, including ethanol and citric acid concentrations, extraction temperature, and duration, were investigated. For each of the investigated parameters, a quadratic model was suggested. The maximum and minimum variables investigated in the coded form of the experimental plan are the concentrations of citric acid (0.10–2.64%), ethanol (38.06–96.93%), operating temperature (13.06–71.90 °C), and extraction time (11.36–78.63 min). The optimal mixture for recovering the most significant amount of polyphenol content and antioxidant activity was 85% ethanol, 0.85% citric acid, 52.14 min, and 57 °C. Based on the experimental approach, the anthocyanin content ranged from 1.71 to 2.74 mg C3G/g DW...
The present paper investigates the optimal control of the photosynthetic growth process in an art... more The present paper investigates the optimal control of the photosynthetic growth process in an artificial light photobioreactor operated in batch mode, the objective being to find an optimal incident light intensity for which the consumption of light energy, for any amount of newly formed biomass, is minimal. By using a simple and reliable model for the photosynthetic growth of microalgae of microalgae, predictions can be made on the quantity of produced biomass and on the amount of light consumed, whose ratio gives the biomass yield on light energy. This variable is unimodal on the allowed range of incident light intensities and has been used as objective function. An improved objective function is proposed by using the specific growth rate and a weighing factor that allows obtaining the desired amount of biomass while the light energy consumption is optimal. A closed-loop control structure has been designed based on the developed optimization algorithm. The optimal controller has b...
The objective of this study was to encapsulate anthocyanins from red onion skins into different b... more The objective of this study was to encapsulate anthocyanins from red onion skins into different biopolymeric matrices as a way to develop powders with multifunctional activities. Two different variants of powders were obtained using a combination of gelation and freeze-drying techniques and characterized by encapsulation efficiency, antioxidant activity, phytochemical content, and color. Stability during storage and the bioavailability of anthocyanins in the in vitro simulated digestion were also examined. Powder V2, with a higher concentration of polysaccharides than V1, allowed a better encapsulation efficiency (90.53 ± 0.29%) and good stability during storage. Both variants had a high content of phytochemicals and antioxidant activity. In vitro investigations proved that an increased polysaccharides concentration offers the best protection for anthocyanins. Thus, a controlled release of the anthocyanins in the intestinal medium was achieved. The powder with the highest encapsulat...
Beetroot peel is a by-product obtained during the processing of beetroots and is an essential sou... more Beetroot peel is a by-product obtained during the processing of beetroots and is an essential source of bioactive substances beneficial to health. This study used antioxidant-rich beetroot peels powder (BPP) in different concentrations (1.5, 3, 5, and 7%) to obtain value-added mayonnaise. The impact of BPP on the phytochemical composition, sensory characteristics, viscosity, color, and textural properties of the mayonnaises were also investigated. The BPP was characterized by a high betalain content (1.18 ± 0.03 mg/g DW) and rich polyphenolic content (225.36 ± 1.97 mg GAE/g DW) and showed high antioxidant activity. The purple-red colored powders added to the mayonnaise allowed a significant increase in total phenolic content and the antioxidant activity of purple-red colored powders added to the mayonnaise. The total color difference ΔE value in the mayonnaise samples increased with extract concentration. The instrumental texture analysis findings revealed that BPP addition to the m...
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Agriculture, 2010
Lipids hydrolysis in self-microemulsifying system with lipase increases the practical approaches ... more Lipids hydrolysis in self-microemulsifying system with lipase increases the practical approaches of emulsions as food additives with biopreservation potential. This study aimed improved bioactive functions of raw coconut fat hydrolysates using self-microemulsifying oily formulation to intensify hydrolysis yield, stabilization of compounds of hydrolysis and control antimicrobial action by controlled release in model and food systems. For microemulsions characterization has been made pseudoternary phase diagrams and have highlighted reports of mixing A / W / S / CoS corresponding states of microemulsion. Microemulsions obtained are stable and provides good stabilization of oil, up to 70% w/w water. Through viscosimetric and conductometric analysis have highlighted the transition states of micro W/O, O/W bicontinuous structures. The antimicrobial activity of microemulsions was evaluated upon spoilage microorganisms as: Bacillus subtilis, Sarcina flava, Saccharomyces cerevisiae, Rhodoth...
Goat milk fat is known for the higher content of shortand mediumchain fatty acids, which have ant... more Goat milk fat is known for the higher content of shortand mediumchain fatty acids, which have antibacterial and antifungal properties. By solid state enzymatic hydrolysis of goat milk fat, using different Candida lipolytica strains as lipase sources, were obtained hydrolysate products with antimicrobial activity. The antimicrobial properties of hydrolysates against some spoilage microorganisms, bacteria (Bacillus subtilis, Bacillus cereus) and fungi (Saccharomyces cerevisae, Candida mycoderma, Rhodotorula glutinis, Aspergillus niger, Penicillium spp. and Geotrichum candidum) were evaluated. Hydrolysate extracts produced by hydrolysis activity of Candida lipolytica G.01.3.1strain exerted inhibitory effect against bacteria, as well as fungi. The results of this study could be considered promising for developing new natural preservatives that could be used in food industry in order to reduce food contamination, increase the shelf life and for food safety assurance.
2021 25th International Conference on System Theory, Control and Computing (ICSTCC), 2021
Data driven control assembles new techniques that can use data from the plant and find the parame... more Data driven control assembles new techniques that can use data from the plant and find the parameters of the controllers that achieve the desired behavior. The paper presents a simplified virtual reference feedback tuning method applied on the photosynthetic growth process of microalgae in photo bioreactor. The complex nonlinear nature of the process requires multiple control channels to establish the proper operating conditions for high growth yields. Two control channels were selected, namely dilution- biomass and CO2 gas flow-pH, on which independent controllers were designed. The data used for training was obtained with a benchmark model that was validated on different reactor types and microalgae strains. The obtained controllers were validated in simulation and proved to attenuate the interferences between the control channels.
A series of yeast strains was tested in order to evaluate their catalytic potential in biocatalys... more A series of yeast strains was tested in order to evaluate their catalytic potential in biocatalysis of one-pot indolizine’s synthesis. Yeast cultivation was performed in a submerged system at 28 °C for 72 h at 180 rpm. An assessment of the reagents’ toxicity on yeast viability and metabolic functionality concluded that the growth potential of three Yarrowia lipolytica strains were least affected by the reactants compared to the other yeast strains. Further, crude fermentation products (biomass and cell-free supernatant)—obtained by submerged cultivation of these yeasts—were used in multistep cascade reactions for the production of fluorescent indolizine compounds with important biologic activities. A whole–cell catalyzed multicomponent reaction of activated alkynes, α-bromo-carbonyl reagents and 4,4′-bipyridine, at room temperature in buffer solution led to the efficient synthesis of bis-indolizines 4a, 4b and 4c, in good-to-excellent yields (47%–77%). The metabolites of the selecte...
Common cereal processing through germination and fermentation usually has an important impact on ... more Common cereal processing through germination and fermentation usually has an important impact on the technological performance of the flours, mainly because of the activation of endogenous enzymes acting on macromolecules. The aim of the present study is to estimate the effect of germination and fermentation, using a mixture of Lactobacillus casei and Kluyveromyces marxianus subsp. marxianus, on the rheological properties of different wheat and triticale varieties. Moreover, the thermo-mechanical behaviour of the white wheat flour-based dough, including germinated grain flour or sourdough was also tested. Grains germination and sourdough fermentation exerted a high influence on the rheological behaviour of the flour-based suspensions. Germination affected the structure and stability of the suspensions, resulting in samples with viscous behaviour prevailing over the elastic one. The temperature ramp tests revealed that germination together with fermentation lead to higher resistance ...
In this study, antioxidant-rich eggplant peel extract was used to obtain a value-added pastry cre... more In this study, antioxidant-rich eggplant peel extract was used to obtain a value-added pastry cream. In order to reduce the susceptibility to degradation, microencapsulation of the biologically active compounds from the eggplant peel was first performed. The microencapsulated bioactive compounds powder (MBC) obtained through freeze-drying retained about 94.31% of the anthocyanins present in the extract, was rich in phenolic compounds, and displayed a high antioxidant activity. The purple colored powder was added to the pastry cream in different concentrations (5% and 10%), allowing significant increase of total phenolic content and antioxidant activity, which were rather stable over 72 h of storage under refrigeration conditions. Sensory evaluation indicated that addition of MBC resulted in improved color and overall acceptability of the pastry cream formulation. All pastry cream samples exhibited rheological behavior specific to the weak gel-like structures, with increasing values ...
Manufacturing beer with a high biological value requires identifying new methods for increasing t... more Manufacturing beer with a high biological value requires identifying new methods for increasing the health-enhancing compounds level. The aim of this study was to increase the biological value of beer by adding antioxidant-rich eggplant (Solanum melongena L.) peel extract (EPE). The total phenolic content (TPC), total flavonoid content (TFC), and total monomeric anthocyanin content (TMA) were determined. Moreover, the antioxidant activity was evaluated by different radical scavenging assays. The addition of different levels of EPE resulted in a significant increase of TPC and TFC of beer samples from 0.426 to 0.631 mg GAE/mL, and from 0.065 to 0.171 mg CE/mL, respectively. The EPE-supplemented beer samples developed a reddish color because of the presence of anthocyanin pigments. The TMA content of beer varied from 0.011 to 0.083 mg D3G/mL with the level of added EPE. The HPLC analysis indicated that the anthocyanins prevailing in the eggplant peels were delphinidin-3-rutinoside, de...
A family of fifteen quaternary ammonium salts (QAs), bearing the 1,2-bis(4-pyridyl)ethane core, w... more A family of fifteen quaternary ammonium salts (QAs), bearing the 1,2-bis(4-pyridyl)ethane core, were obtained using for the first time two different green methods, such as microwave (MW) and ultrasounds (US) irradiation, with very good yields and in much shorter times compared to the classical method, and an assay on their antimicrobial action against Escherichia coli (E. coli) was carried out. While 12 to 24 hours were required for complete alkylation of 1,2-bis(4-pyridyl)ethane by reactive halogenated derivatives in anhydrous solvent under reflux conditions, MW and US irradiation reduced the reaction time and the desired products were achieved in a few min. One of the aims of this study was to evaluate the antibacterial potential of the synthesized QAs against pathogenic bacteria, along with their impact on germination activity of wheat seeds (Triticum aestivum L.). The antibacterial activity of the QAs against Escherichia coli was explored by determining the minimum inhibitory co...
DOAJ (DOAJ: Directory of Open Access Journals), Jun 1, 2012
Coconut fat could be an important source of bioactive compounds with a large applicability in ind... more Coconut fat could be an important source of bioactive compounds with a large applicability in industry. In this study it was realized the enzymatic hydrolysis of coconut fat with different yeast strains of Yarrowia lipolytica. The aim of this study was to optimize the hydrolysis conditions and determination of Yarrowia lipolytica specificity on coconut fat as substrate. The hydrolysis was performed by yeast strains cultivated on stationary solid state conditions on spirit blue agar medium supplemented with 3% coconut fat, at 25°C and 4°C, and at values of water activity of 0.98, 0.96 and 0.93. The substrate hydrolysis index was recorded every 24 hours, during of 240 hours of stationary cultivation. The most active lipolytic yeast was strain coded S5 which produce a high level of extracellular lipase with high coconut hydrolyze activity at 25°C and two water activities 0.98 and 0.96, in the shortest time (24 – 72 hours). In the presence of 3% NaCl in media, the strains coded S9, S5 and S4 were the most active from all tested strains at 25°C and 4°C. At low temperatures and in presence of 10.1% NaCl all tested yeasts had no lipolytic activity.
Using a Central Composite Design, the extraction of bioactive compounds from red grape Băbească n... more Using a Central Composite Design, the extraction of bioactive compounds from red grape Băbească neagră peels was optimized by applying a conventional solvent extraction. On the anthocyanin content, total phenolic content, and antioxidant activity (using the DPPH method), the effects of extraction factors, including ethanol and citric acid concentrations, extraction temperature, and duration, were investigated. For each of the investigated parameters, a quadratic model was suggested. The maximum and minimum variables investigated in the coded form of the experimental plan are the concentrations of citric acid (0.10–2.64%), ethanol (38.06–96.93%), operating temperature (13.06–71.90 °C), and extraction time (11.36–78.63 min). The optimal mixture for recovering the most significant amount of polyphenol content and antioxidant activity was 85% ethanol, 0.85% citric acid, 52.14 min, and 57 °C. Based on the experimental approach, the anthocyanin content ranged from 1.71 to 2.74 mg C3G/g DW...
The present paper investigates the optimal control of the photosynthetic growth process in an art... more The present paper investigates the optimal control of the photosynthetic growth process in an artificial light photobioreactor operated in batch mode, the objective being to find an optimal incident light intensity for which the consumption of light energy, for any amount of newly formed biomass, is minimal. By using a simple and reliable model for the photosynthetic growth of microalgae of microalgae, predictions can be made on the quantity of produced biomass and on the amount of light consumed, whose ratio gives the biomass yield on light energy. This variable is unimodal on the allowed range of incident light intensities and has been used as objective function. An improved objective function is proposed by using the specific growth rate and a weighing factor that allows obtaining the desired amount of biomass while the light energy consumption is optimal. A closed-loop control structure has been designed based on the developed optimization algorithm. The optimal controller has b...
The objective of this study was to encapsulate anthocyanins from red onion skins into different b... more The objective of this study was to encapsulate anthocyanins from red onion skins into different biopolymeric matrices as a way to develop powders with multifunctional activities. Two different variants of powders were obtained using a combination of gelation and freeze-drying techniques and characterized by encapsulation efficiency, antioxidant activity, phytochemical content, and color. Stability during storage and the bioavailability of anthocyanins in the in vitro simulated digestion were also examined. Powder V2, with a higher concentration of polysaccharides than V1, allowed a better encapsulation efficiency (90.53 ± 0.29%) and good stability during storage. Both variants had a high content of phytochemicals and antioxidant activity. In vitro investigations proved that an increased polysaccharides concentration offers the best protection for anthocyanins. Thus, a controlled release of the anthocyanins in the intestinal medium was achieved. The powder with the highest encapsulat...
Beetroot peel is a by-product obtained during the processing of beetroots and is an essential sou... more Beetroot peel is a by-product obtained during the processing of beetroots and is an essential source of bioactive substances beneficial to health. This study used antioxidant-rich beetroot peels powder (BPP) in different concentrations (1.5, 3, 5, and 7%) to obtain value-added mayonnaise. The impact of BPP on the phytochemical composition, sensory characteristics, viscosity, color, and textural properties of the mayonnaises were also investigated. The BPP was characterized by a high betalain content (1.18 ± 0.03 mg/g DW) and rich polyphenolic content (225.36 ± 1.97 mg GAE/g DW) and showed high antioxidant activity. The purple-red colored powders added to the mayonnaise allowed a significant increase in total phenolic content and the antioxidant activity of purple-red colored powders added to the mayonnaise. The total color difference ΔE value in the mayonnaise samples increased with extract concentration. The instrumental texture analysis findings revealed that BPP addition to the m...
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Agriculture, 2010
Lipids hydrolysis in self-microemulsifying system with lipase increases the practical approaches ... more Lipids hydrolysis in self-microemulsifying system with lipase increases the practical approaches of emulsions as food additives with biopreservation potential. This study aimed improved bioactive functions of raw coconut fat hydrolysates using self-microemulsifying oily formulation to intensify hydrolysis yield, stabilization of compounds of hydrolysis and control antimicrobial action by controlled release in model and food systems. For microemulsions characterization has been made pseudoternary phase diagrams and have highlighted reports of mixing A / W / S / CoS corresponding states of microemulsion. Microemulsions obtained are stable and provides good stabilization of oil, up to 70% w/w water. Through viscosimetric and conductometric analysis have highlighted the transition states of micro W/O, O/W bicontinuous structures. The antimicrobial activity of microemulsions was evaluated upon spoilage microorganisms as: Bacillus subtilis, Sarcina flava, Saccharomyces cerevisiae, Rhodoth...
Goat milk fat is known for the higher content of shortand mediumchain fatty acids, which have ant... more Goat milk fat is known for the higher content of shortand mediumchain fatty acids, which have antibacterial and antifungal properties. By solid state enzymatic hydrolysis of goat milk fat, using different Candida lipolytica strains as lipase sources, were obtained hydrolysate products with antimicrobial activity. The antimicrobial properties of hydrolysates against some spoilage microorganisms, bacteria (Bacillus subtilis, Bacillus cereus) and fungi (Saccharomyces cerevisae, Candida mycoderma, Rhodotorula glutinis, Aspergillus niger, Penicillium spp. and Geotrichum candidum) were evaluated. Hydrolysate extracts produced by hydrolysis activity of Candida lipolytica G.01.3.1strain exerted inhibitory effect against bacteria, as well as fungi. The results of this study could be considered promising for developing new natural preservatives that could be used in food industry in order to reduce food contamination, increase the shelf life and for food safety assurance.
2021 25th International Conference on System Theory, Control and Computing (ICSTCC), 2021
Data driven control assembles new techniques that can use data from the plant and find the parame... more Data driven control assembles new techniques that can use data from the plant and find the parameters of the controllers that achieve the desired behavior. The paper presents a simplified virtual reference feedback tuning method applied on the photosynthetic growth process of microalgae in photo bioreactor. The complex nonlinear nature of the process requires multiple control channels to establish the proper operating conditions for high growth yields. Two control channels were selected, namely dilution- biomass and CO2 gas flow-pH, on which independent controllers were designed. The data used for training was obtained with a benchmark model that was validated on different reactor types and microalgae strains. The obtained controllers were validated in simulation and proved to attenuate the interferences between the control channels.
A series of yeast strains was tested in order to evaluate their catalytic potential in biocatalys... more A series of yeast strains was tested in order to evaluate their catalytic potential in biocatalysis of one-pot indolizine’s synthesis. Yeast cultivation was performed in a submerged system at 28 °C for 72 h at 180 rpm. An assessment of the reagents’ toxicity on yeast viability and metabolic functionality concluded that the growth potential of three Yarrowia lipolytica strains were least affected by the reactants compared to the other yeast strains. Further, crude fermentation products (biomass and cell-free supernatant)—obtained by submerged cultivation of these yeasts—were used in multistep cascade reactions for the production of fluorescent indolizine compounds with important biologic activities. A whole–cell catalyzed multicomponent reaction of activated alkynes, α-bromo-carbonyl reagents and 4,4′-bipyridine, at room temperature in buffer solution led to the efficient synthesis of bis-indolizines 4a, 4b and 4c, in good-to-excellent yields (47%–77%). The metabolites of the selecte...
Common cereal processing through germination and fermentation usually has an important impact on ... more Common cereal processing through germination and fermentation usually has an important impact on the technological performance of the flours, mainly because of the activation of endogenous enzymes acting on macromolecules. The aim of the present study is to estimate the effect of germination and fermentation, using a mixture of Lactobacillus casei and Kluyveromyces marxianus subsp. marxianus, on the rheological properties of different wheat and triticale varieties. Moreover, the thermo-mechanical behaviour of the white wheat flour-based dough, including germinated grain flour or sourdough was also tested. Grains germination and sourdough fermentation exerted a high influence on the rheological behaviour of the flour-based suspensions. Germination affected the structure and stability of the suspensions, resulting in samples with viscous behaviour prevailing over the elastic one. The temperature ramp tests revealed that germination together with fermentation lead to higher resistance ...
In this study, antioxidant-rich eggplant peel extract was used to obtain a value-added pastry cre... more In this study, antioxidant-rich eggplant peel extract was used to obtain a value-added pastry cream. In order to reduce the susceptibility to degradation, microencapsulation of the biologically active compounds from the eggplant peel was first performed. The microencapsulated bioactive compounds powder (MBC) obtained through freeze-drying retained about 94.31% of the anthocyanins present in the extract, was rich in phenolic compounds, and displayed a high antioxidant activity. The purple colored powder was added to the pastry cream in different concentrations (5% and 10%), allowing significant increase of total phenolic content and antioxidant activity, which were rather stable over 72 h of storage under refrigeration conditions. Sensory evaluation indicated that addition of MBC resulted in improved color and overall acceptability of the pastry cream formulation. All pastry cream samples exhibited rheological behavior specific to the weak gel-like structures, with increasing values ...
Manufacturing beer with a high biological value requires identifying new methods for increasing t... more Manufacturing beer with a high biological value requires identifying new methods for increasing the health-enhancing compounds level. The aim of this study was to increase the biological value of beer by adding antioxidant-rich eggplant (Solanum melongena L.) peel extract (EPE). The total phenolic content (TPC), total flavonoid content (TFC), and total monomeric anthocyanin content (TMA) were determined. Moreover, the antioxidant activity was evaluated by different radical scavenging assays. The addition of different levels of EPE resulted in a significant increase of TPC and TFC of beer samples from 0.426 to 0.631 mg GAE/mL, and from 0.065 to 0.171 mg CE/mL, respectively. The EPE-supplemented beer samples developed a reddish color because of the presence of anthocyanin pigments. The TMA content of beer varied from 0.011 to 0.083 mg D3G/mL with the level of added EPE. The HPLC analysis indicated that the anthocyanins prevailing in the eggplant peels were delphinidin-3-rutinoside, de...
A family of fifteen quaternary ammonium salts (QAs), bearing the 1,2-bis(4-pyridyl)ethane core, w... more A family of fifteen quaternary ammonium salts (QAs), bearing the 1,2-bis(4-pyridyl)ethane core, were obtained using for the first time two different green methods, such as microwave (MW) and ultrasounds (US) irradiation, with very good yields and in much shorter times compared to the classical method, and an assay on their antimicrobial action against Escherichia coli (E. coli) was carried out. While 12 to 24 hours were required for complete alkylation of 1,2-bis(4-pyridyl)ethane by reactive halogenated derivatives in anhydrous solvent under reflux conditions, MW and US irradiation reduced the reaction time and the desired products were achieved in a few min. One of the aims of this study was to evaluate the antibacterial potential of the synthesized QAs against pathogenic bacteria, along with their impact on germination activity of wheat seeds (Triticum aestivum L.). The antibacterial activity of the QAs against Escherichia coli was explored by determining the minimum inhibitory co...
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