The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform
Fikret Kargi - One of the best experts on this subject based on the ideXlab platform.
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fermentation of cheese whey powder solution to ethanol in a packed column bioreactor effects of feed Sugar Concentration
Journal of Chemical Technology & Biotechnology, 2009Co-Authors: Serpil Ozmihci, Fikret KargiAbstract:BACKGROUND: Cheese whey powder (CWP) is a concentrated source of lactose and other essential nutrients for ethanol fermentation. CWP solution containing different Concentrations of total Sugar was fermented to ethanol in an up-flow packed-column bioreactor (PCBR) at a constant hydraulic residence time (HRT) of 50 h. Total Sugar Concentration in the feed was varied between 50 and 200 g L−1 and a pure culture of Kluyveromyces marxianus was used for ethanol fermentation of lactose. Variations of ethanol and Sugar Concentrations with the height of the column and with the feed Sugar Concentration were determined. RESULTS: Ethanol Concentration increased and total Sugar decreased with the column height for all feed Sugar contents. The highest effluent ethanol Concentration (22.5 g L−1) and ethanol formation rate were obtained with feed Sugar content of 100 g L−1. Percentage Sugar utilization decreased with increasing feed Sugar content above 100 g L−1 yielding lower ethanol contents in the effluent. The highest ethanol yield coefficient (0.52 gE g−1S) was obtained with a feed Sugar content of 50 g L−1. Biomass Concentration also decreased with column height, yielding low ethanol formation in the upper section of the column. CONCLUSION: The packed column bioreactor was found to be effective for ethanol fermentation from CWP solution. The optimum feed Sugar content maximizing the effluent ethanol and the specific rate of ethanol formation was found to be 100 g L−1. High Sugar content above 100 g L−1 resulted in low ethanol productivities due to high maintenance requirements. Copyright © 2008 Society of Chemical Industry
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fermentation of cheese whey powder solution to ethanol in a packed column bioreactor effects of feed Sugar Concentration
Journal of Chemical Technology & Biotechnology, 2009Co-Authors: Serpil Ozmihci, Fikret KargiAbstract:BACKGROUND: Cheese whey powder (CWP) is a concentrated source of lactose and other essential nutrients for ethanol fermentation. CWP solution containing different Concentrations of total Sugar was fermented to ethanol in an up-flow packed-column bioreactor (PCBR) at a constant hydraulic residence time (HRT) of 50 h. Total Sugar Concentration in the feed was varied between 50 and 200 g L -1 and a pure culture of Kluyveromyces marxianus was used for ethanol fermentation of lactose. Variations of ethanol and Sugar Concentrations with the height of the column and with the feed Sugar Concentration were determined. RESULTS: Ethanol Concentration increased and total Sugar decreased with the column height for all feed Sugar contents. The highest effluent ethanol Concentration (22.5 g L -1 ) and ethanol formation rate were obtained with feed Sugar content of 100 g L -1 . Percentage Sugar utilization decreased with increasing feed Sugar content above 100 g L -1 yielding lower ethanol contents in the effluent. The highest ethanol yield coefficient (0.52 gE g -1 S) was obtained with a feed Sugar content of 50 g L -1 . Biomass Concentration also decreased with column height, yielding low ethanol formation in the upper section of the column. CONCLUSION: The packed column bioreactor was found to be effective for ethanol fermentation from CWP solution. The optimum feed Sugar content maximizing the effluent ethanol and the specific rate of ethanol formation was found to be 100 g L -1 . High Sugar content above 100 g L -1 resulted in low ethanol productivities due to high maintenance requirements.
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effects of feed Sugar Concentration on continuous ethanol fermentation of cheese whey powder solution cwp
Enzyme and Microbial Technology, 2007Co-Authors: Serpil Ozmihci, Fikret KargiAbstract:Abstract Cheese whey powder (CWP) solution with different CWP or Sugar Concentrations was fermented to ethanol in a continuous fermenter using pure culture of Kluyveromyces marxianus (DSMZ 7239). Sugar Concentration of the feed CWP solution varied between 55 and 200 g l −1 while the hydraulic residence time (HRT) was kept constant at 54 h. Ethanol formation, Sugar utilization and biomass formation were investigated as functions of the feed Sugar Concentration. Percent Sugar utilization and biomass Concentrations decreased and the effluent Sugar Concentration increased with increasing feed Sugar Concentrations especially for the feed Sugar contents above 100 g l −1 . Ethanol Concentration and productivity (DP) increased with increasing feed Sugar up to 100 g l −1 and then decreased with further increases in the feed Sugar content. The highest ethanol Concentration (3.7%, v v −1 ) and productivity (0.54 gE l −1 h −1 ) were obtained with the feed Sugar content of 100 g l −1 or 125 g l −1 . The ethanol yield coefficient ( Y P/S ) was also maximum (0.49 gE gS −1 ) when the feed Sugar was between 100 and 125 g l −1 . The growth yield coefficient ( Y X/S ) decreased steadily from 0.123 to 0.063 gX gS −1 when the feed Sugar increased from 55 to 200 g l −1 due to adverse effects of high Sugar contents on yeast growth. The optimal feed Sugar Concentration maximizing the ethanol productivity and Sugar utilization was between 100 and 125 g l −1 under the specified experimental conditions.
R. Giangiacomo - One of the best experts on this subject based on the ideXlab platform.
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study of water Sugar interactions at increasing Sugar Concentration by nir spectroscopy
Food Chemistry, 2006Co-Authors: R. GiangiacomoAbstract:Abstract Near infrared spectroscopy has been extensively used to determine the water behaviour at different temperatures and different physical state. The purpose of the present work was to investigate the spectroscopic response in the range 1100–2400 nm of solutions of glucose, fructose, and sucrose at Concentrations 5–65%. Data indicate that by increasing Sugar Concentration the water band becomes more symmetric and there is a shift of the absorption maximum toward longer wavelengths. Spectra were interpreted in terms of “structure-maker” and “structure-breaker” effects of increasing Sugar Concentration. Sugars at low Concentrations behave as structure breaker of the water cluster, while at higher Concentrations they act as structure makers. These results could be of some interest when monitoring by NIR processes as freezing, freeze-drying, drying, cryoConcentration, etc. of fruits and vegetables, where the removal or separation of large amounts of water induce the formation of very concentrated Sugars solutions.
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Study of water–Sugar interactions at increasing Sugar Concentration by NIR spectroscopy
Food Chemistry, 2006Co-Authors: R. GiangiacomoAbstract:Abstract Near infrared spectroscopy has been extensively used to determine the water behaviour at different temperatures and different physical state. The purpose of the present work was to investigate the spectroscopic response in the range 1100–2400 nm of solutions of glucose, fructose, and sucrose at Concentrations 5–65%. Data indicate that by increasing Sugar Concentration the water band becomes more symmetric and there is a shift of the absorption maximum toward longer wavelengths. Spectra were interpreted in terms of “structure-maker” and “structure-breaker” effects of increasing Sugar Concentration. Sugars at low Concentrations behave as structure breaker of the water cluster, while at higher Concentrations they act as structure makers. These results could be of some interest when monitoring by NIR processes as freezing, freeze-drying, drying, cryoConcentration, etc. of fruits and vegetables, where the removal or separation of large amounts of water induce the formation of very concentrated Sugars solutions.
Michel Génard - One of the best experts on this subject based on the ideXlab platform.
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Inter-species comparative analysis of components of soluble Sugar Concentration in fleshy fruits
Frontiers in Plant Science, 2016Co-Authors: Zhanwu Dai, Valentina Baldazzi, Cornelis Van Leeuwen, Nadia Bertin, Hélène Gautier, Eric Duchêne, Eric Gomes, Serge Delrot, Françoise Lescourret, Michel GénardAbstract:The soluble Sugar Concentration of fleshy fruit is a key determinant of fleshy fruit quality. It affects directly the sweetness of fresh fruits and indirectly the properties of processed products (e.g., alcohol content in wine). Despite considerable divergence among species, soluble Sugar accumulation in a fruit results from the complex interplay of three main processes, namely Sugar import, Sugar metabolism, and water dilution. Therefore, inter-species comparison would help to identify common and/or species-specific modes of regulation in Sugar accumulation. For this purpose, a process-based mathematical framework was used to compare soluble Sugar accumulation in three fruits: grape, tomato, and peach. Representative datasets covering the time course of Sugar accumulation during fruit development were collected. They encompassed 104 combinations of species (3), genotypes (30), and growing conditions (19 years and 16 nutrient and environmental treatments). At maturity, grape showed the highest soluble Sugar Concentrations (16.5–26.3 g/100 g FW), followed by peach (2.2 to 20 g/100 g FW) and tomato (1.4 to 5 g/100 g FW). Main processes determining soluble Sugar Concentration were decomposed into Sugar importation, metabolism, and water dilution with the process-based analysis. Different regulation modes of soluble Sugar Concentration were then identified, showing either import-based, dilution-based, or import and dilution dual-based. Firstly, the higher soluble Sugar Concentration in grape than in tomato is a result of higher Sugar importation. Secondly, the higher soluble Sugar Concentration in grape than in peach is due to a lower water dilution. The third mode of regulation is more complicated than the first two, with differences both in Sugar importation and water dilution (grape vs. cherry tomato; cherry tomato vs. peach; peach vs. tomato). On the other hand, carbon utilization for synthesis of non-soluble Sugar compounds (namely metabolism) was conserved among the three fruit species. These distinct modes appear to be quite species-specific, but the intensity of the effect may significantly vary depending on the genotype and management practices. These results provide novel insights into the drivers of differences in soluble Sugar Concentration among fleshy fruits.
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Combining ecophysiological modelling and quantitative trait locus analysis to identify key elementary processes underlying tomato fruit Sugar Concentration
Journal of Experimental Botany, 2011Co-Authors: Marion Prudent, Nadia Bertin, Alain Lecomte, Jean-paul Bouchet, Mathilde Causse, Michel GénardAbstract:A mechanistic model predicting the accumulation of tomato fruit Sugars was developed in order (i) to dissect the relative influence of three underlying processes: assimilate supply (S), metabolic transformation of Sugars into other compounds (M), and dilution by water uptake (D); and (ii) to estimate the genetic variability of S, M, and D. The latter was estimated in a population of 20 introgression lines derived from the introgression of a wild tomato species (Solanum chmielewskii) into S. lycopersicum, grown under two contrasted fruit load conditions. Low load systematically decreased D in the whole population, while S and M were targets of genotype×fruit load interactions. The Sugar Concentration positively correlated to S and D when the variation was due to genetic introgressions, while it positively correlated to S and M when the variation was due to changes in fruit load. Co-localizations between quantitative trait loci (QTLs) for Sugar Concentration and QTLs for S, M, and D allowed hypotheses to be proposed on the processes putatively involved at the QTLs. Among the five QTLs for Sugar Concentration, four co-localized with QTLs for S, M, and D with similar allele effects. Moreover, the processes underlying QTLs for Sugar accumulation changed according to the fruit load condition. Finally, for some genotypes, the processes underlying Sugar Concentration compensated in such a way that they did not modify the Sugar Concentration. By uncoupling genetic from physiological relationships between processes, these results provide new insights into further understanding of tomato fruit Sugar accumulation.
Serpil Ozmihci - One of the best experts on this subject based on the ideXlab platform.
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fermentation of cheese whey powder solution to ethanol in a packed column bioreactor effects of feed Sugar Concentration
Journal of Chemical Technology & Biotechnology, 2009Co-Authors: Serpil Ozmihci, Fikret KargiAbstract:BACKGROUND: Cheese whey powder (CWP) is a concentrated source of lactose and other essential nutrients for ethanol fermentation. CWP solution containing different Concentrations of total Sugar was fermented to ethanol in an up-flow packed-column bioreactor (PCBR) at a constant hydraulic residence time (HRT) of 50 h. Total Sugar Concentration in the feed was varied between 50 and 200 g L−1 and a pure culture of Kluyveromyces marxianus was used for ethanol fermentation of lactose. Variations of ethanol and Sugar Concentrations with the height of the column and with the feed Sugar Concentration were determined. RESULTS: Ethanol Concentration increased and total Sugar decreased with the column height for all feed Sugar contents. The highest effluent ethanol Concentration (22.5 g L−1) and ethanol formation rate were obtained with feed Sugar content of 100 g L−1. Percentage Sugar utilization decreased with increasing feed Sugar content above 100 g L−1 yielding lower ethanol contents in the effluent. The highest ethanol yield coefficient (0.52 gE g−1S) was obtained with a feed Sugar content of 50 g L−1. Biomass Concentration also decreased with column height, yielding low ethanol formation in the upper section of the column. CONCLUSION: The packed column bioreactor was found to be effective for ethanol fermentation from CWP solution. The optimum feed Sugar content maximizing the effluent ethanol and the specific rate of ethanol formation was found to be 100 g L−1. High Sugar content above 100 g L−1 resulted in low ethanol productivities due to high maintenance requirements. Copyright © 2008 Society of Chemical Industry
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fermentation of cheese whey powder solution to ethanol in a packed column bioreactor effects of feed Sugar Concentration
Journal of Chemical Technology & Biotechnology, 2009Co-Authors: Serpil Ozmihci, Fikret KargiAbstract:BACKGROUND: Cheese whey powder (CWP) is a concentrated source of lactose and other essential nutrients for ethanol fermentation. CWP solution containing different Concentrations of total Sugar was fermented to ethanol in an up-flow packed-column bioreactor (PCBR) at a constant hydraulic residence time (HRT) of 50 h. Total Sugar Concentration in the feed was varied between 50 and 200 g L -1 and a pure culture of Kluyveromyces marxianus was used for ethanol fermentation of lactose. Variations of ethanol and Sugar Concentrations with the height of the column and with the feed Sugar Concentration were determined. RESULTS: Ethanol Concentration increased and total Sugar decreased with the column height for all feed Sugar contents. The highest effluent ethanol Concentration (22.5 g L -1 ) and ethanol formation rate were obtained with feed Sugar content of 100 g L -1 . Percentage Sugar utilization decreased with increasing feed Sugar content above 100 g L -1 yielding lower ethanol contents in the effluent. The highest ethanol yield coefficient (0.52 gE g -1 S) was obtained with a feed Sugar content of 50 g L -1 . Biomass Concentration also decreased with column height, yielding low ethanol formation in the upper section of the column. CONCLUSION: The packed column bioreactor was found to be effective for ethanol fermentation from CWP solution. The optimum feed Sugar content maximizing the effluent ethanol and the specific rate of ethanol formation was found to be 100 g L -1 . High Sugar content above 100 g L -1 resulted in low ethanol productivities due to high maintenance requirements.
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effects of feed Sugar Concentration on continuous ethanol fermentation of cheese whey powder solution cwp
Enzyme and Microbial Technology, 2007Co-Authors: Serpil Ozmihci, Fikret KargiAbstract:Abstract Cheese whey powder (CWP) solution with different CWP or Sugar Concentrations was fermented to ethanol in a continuous fermenter using pure culture of Kluyveromyces marxianus (DSMZ 7239). Sugar Concentration of the feed CWP solution varied between 55 and 200 g l −1 while the hydraulic residence time (HRT) was kept constant at 54 h. Ethanol formation, Sugar utilization and biomass formation were investigated as functions of the feed Sugar Concentration. Percent Sugar utilization and biomass Concentrations decreased and the effluent Sugar Concentration increased with increasing feed Sugar Concentrations especially for the feed Sugar contents above 100 g l −1 . Ethanol Concentration and productivity (DP) increased with increasing feed Sugar up to 100 g l −1 and then decreased with further increases in the feed Sugar content. The highest ethanol Concentration (3.7%, v v −1 ) and productivity (0.54 gE l −1 h −1 ) were obtained with the feed Sugar content of 100 g l −1 or 125 g l −1 . The ethanol yield coefficient ( Y P/S ) was also maximum (0.49 gE gS −1 ) when the feed Sugar was between 100 and 125 g l −1 . The growth yield coefficient ( Y X/S ) decreased steadily from 0.123 to 0.063 gX gS −1 when the feed Sugar increased from 55 to 200 g l −1 due to adverse effects of high Sugar contents on yeast growth. The optimal feed Sugar Concentration maximizing the ethanol productivity and Sugar utilization was between 100 and 125 g l −1 under the specified experimental conditions.
Nadia Bertin - One of the best experts on this subject based on the ideXlab platform.
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Inter-species comparative analysis of components of soluble Sugar Concentration in fleshy fruits
Frontiers in Plant Science, 2016Co-Authors: Zhanwu Dai, Valentina Baldazzi, Cornelis Van Leeuwen, Nadia Bertin, Hélène Gautier, Eric Duchêne, Eric Gomes, Serge Delrot, Françoise Lescourret, Michel GénardAbstract:The soluble Sugar Concentration of fleshy fruit is a key determinant of fleshy fruit quality. It affects directly the sweetness of fresh fruits and indirectly the properties of processed products (e.g., alcohol content in wine). Despite considerable divergence among species, soluble Sugar accumulation in a fruit results from the complex interplay of three main processes, namely Sugar import, Sugar metabolism, and water dilution. Therefore, inter-species comparison would help to identify common and/or species-specific modes of regulation in Sugar accumulation. For this purpose, a process-based mathematical framework was used to compare soluble Sugar accumulation in three fruits: grape, tomato, and peach. Representative datasets covering the time course of Sugar accumulation during fruit development were collected. They encompassed 104 combinations of species (3), genotypes (30), and growing conditions (19 years and 16 nutrient and environmental treatments). At maturity, grape showed the highest soluble Sugar Concentrations (16.5–26.3 g/100 g FW), followed by peach (2.2 to 20 g/100 g FW) and tomato (1.4 to 5 g/100 g FW). Main processes determining soluble Sugar Concentration were decomposed into Sugar importation, metabolism, and water dilution with the process-based analysis. Different regulation modes of soluble Sugar Concentration were then identified, showing either import-based, dilution-based, or import and dilution dual-based. Firstly, the higher soluble Sugar Concentration in grape than in tomato is a result of higher Sugar importation. Secondly, the higher soluble Sugar Concentration in grape than in peach is due to a lower water dilution. The third mode of regulation is more complicated than the first two, with differences both in Sugar importation and water dilution (grape vs. cherry tomato; cherry tomato vs. peach; peach vs. tomato). On the other hand, carbon utilization for synthesis of non-soluble Sugar compounds (namely metabolism) was conserved among the three fruit species. These distinct modes appear to be quite species-specific, but the intensity of the effect may significantly vary depending on the genotype and management practices. These results provide novel insights into the drivers of differences in soluble Sugar Concentration among fleshy fruits.
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Combining ecophysiological modelling and quantitative trait locus analysis to identify key elementary processes underlying tomato fruit Sugar Concentration
Journal of Experimental Botany, 2011Co-Authors: Marion Prudent, Nadia Bertin, Alain Lecomte, Jean-paul Bouchet, Mathilde Causse, Michel GénardAbstract:A mechanistic model predicting the accumulation of tomato fruit Sugars was developed in order (i) to dissect the relative influence of three underlying processes: assimilate supply (S), metabolic transformation of Sugars into other compounds (M), and dilution by water uptake (D); and (ii) to estimate the genetic variability of S, M, and D. The latter was estimated in a population of 20 introgression lines derived from the introgression of a wild tomato species (Solanum chmielewskii) into S. lycopersicum, grown under two contrasted fruit load conditions. Low load systematically decreased D in the whole population, while S and M were targets of genotype×fruit load interactions. The Sugar Concentration positively correlated to S and D when the variation was due to genetic introgressions, while it positively correlated to S and M when the variation was due to changes in fruit load. Co-localizations between quantitative trait loci (QTLs) for Sugar Concentration and QTLs for S, M, and D allowed hypotheses to be proposed on the processes putatively involved at the QTLs. Among the five QTLs for Sugar Concentration, four co-localized with QTLs for S, M, and D with similar allele effects. Moreover, the processes underlying QTLs for Sugar accumulation changed according to the fruit load condition. Finally, for some genotypes, the processes underlying Sugar Concentration compensated in such a way that they did not modify the Sugar Concentration. By uncoupling genetic from physiological relationships between processes, these results provide new insights into further understanding of tomato fruit Sugar accumulation.
