The Experts below are selected from a list of 252 Experts worldwide ranked by ideXlab platform
Manuel Ramirez - One of the best experts on this subject based on the ideXlab platform.
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influence of the dominance of must fermentation by torulaspora delbrueckii on the malolactic fermentation and organoleptic quality of red Table Wine
International Journal of Food Microbiology, 2016Co-Authors: Manuel Ramirez, Rocio Velazquez, Emiliano Zamora, Matilde Maqueda, Antonio Lopezpineiro, Luis M HernandezAbstract:Torulaspora delbrueckii can improve Wine aroma complexity, but its impact on Wine quality is still far from being satisfactory at the Winery level, mainly because it is easily replaced by S. cerevisiae yeasts during must fermentation. New T. delbrueckii killer strains were selected to overcome this problem. These strains killed S. cerevisiae yeasts and dominated fermentation better than T. delbrueckii non-killer strains when they were single-inoculated into crushed red grape must. All the T. delbrueckii Wines, but none of the S. cerevisiae Wines, underwent malolactic fermentation. Putative lactic acid bacteria were always found in the T. delbrueckii Wines, but none or very few in the S. cerevisiae Wines. Malic acid degradation was the greatest in the Wines inoculated with the killer strains, and these strains reached the greatest dominance ratios and had the slowest fermentation kinetics. The T. delbrueckii Wines had dried-fruit/pastry aromas, but low intensities of fresh-fruit aromas. The aroma differences between the T. delbrueckii and the S. cerevisiae Wines can be explained by the differences that were found in the amounts of some fruity aroma compounds such as isoamyl acetate, ethyl hexanoate, ethyl octanoate, and some lactones. This T. delbrueckii effect significantly raised the organoleptic quality scores of full-bodied Cabernet-Sauvignon red Wines inoculated with the killer strains. In particular, these Wines were judged as having excellent aroma complexity, mouth-feel, and sweetness.
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effects of new torulaspora delbrueckii killer yeasts on the must fermentation kinetics and aroma compounds of white Table Wine
Frontiers in Microbiology, 2015Co-Authors: Rocio Velazquez, Emiliano Zamora, Maria L Alvarez, Luis M Hernandez, Manuel RamirezAbstract:Torulaspora delbrueckii is becoming widely recommended for improving some specific characteristics of Wines. However, its impact on Wine quality is still far from satisfactory at the Winery level, mostly because it is easily replaced by S. cerevisiae-like yeasts during must fermentation. New T. delbrueckii killer strains were here isolated and selected for Winemaking. They killed S. cerevisiae yeasts and were able to dominate and complete the fermentation of sterile grape must. Sequential yeast inoculation of non-sterile white must with T. delbrueckii followed by S. cerevisiae did not ensure T. delbrueckii dominance or Wine quality improvement. Only a single initial must inoculation at high cell concentrations allowed the T. delbrueckii killer strains to dominate and complete the must fermentation to reach above 11% ethanol, but not the non-killer strains. None of the Wines underwent malolactic fermentation as long as the must had low turbidity and pH. Although no statistically significant differences were found in the Wine quality score, the S. cerevisiae-dominated Wines were preferred over the T. delbrueckii-dominated ones because the former had high-intensity fresh fruit aromas while the latter had lower intensity, but nevertheless nice and unusual dried fruit/pastry aromas. Except for ethyl propanoate and 3-ethoxy-1-propanol, which were more abundant in the T. delbrueckii–dominated Wines, most of the compounds with fresh fruit odour descriptors, including those with the greatest odour activity values (isoamyl acetate, ethyl hexanoate, and ethyl octanoate), were more abundant in the S. cerevisiae–dominated Wines. The low relative concentrations of these fruity compounds made it possible to detect in the T. delbrueckii–dominated Wines the low-relative-concentration compounds with dried fruit and pastry odours. An example was γ-ethoxy-butyrolactone which was significantly more abundant in these Wines than in those dominated by S. cerevisiae.
Roberto Zironi - One of the best experts on this subject based on the ideXlab platform.
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Interactions between yeast autolysates and volatile compounds in Wine and model solution
Food chemistry, 2011Co-Authors: Piergiorgio Comuzzo, Lara Tat, Dennis Fenzi, Laura Brotto, Franco Battistutta, Roberto ZironiAbstract:The addition of a commercial yeast autolysate to a model solution of five typical Wine aroma compounds (ethyl octanoate, linalool, 2-phenylethanol, β-ionone and octanoic acid) was investigated considering different variables, such as temperature, pH and the presence of highly concentrated natural volatile substances in Wine (e.g. 3-methyl-1-butanol). The interactions of such compounds with both yeast walls and released colloids were studied using gas chromatography, with liquid-liquid extraction and solid-phase microextraction. The results were compared with those obtained by adding the commercial product to a white Table Wine, spiked with the five standard compounds. The data confirmed that yeast walls mainly bind less polar molecules: their loss in synthetic medium seemed to increase at higher pH values. Temperature and pH affected differently the interactions between yeast colloids and volatile compounds in Wine and model solution: in complex solutions (as the addition of 3-methyl-1-butanol demonstrated) the interaction mechanisms could be influenced by competitive or other matrix-related effects, which can reduce the binding of single compounds, or even enhance their volatility.
Rocio Velazquez - One of the best experts on this subject based on the ideXlab platform.
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influence of the dominance of must fermentation by torulaspora delbrueckii on the malolactic fermentation and organoleptic quality of red Table Wine
International Journal of Food Microbiology, 2016Co-Authors: Manuel Ramirez, Rocio Velazquez, Emiliano Zamora, Matilde Maqueda, Antonio Lopezpineiro, Luis M HernandezAbstract:Torulaspora delbrueckii can improve Wine aroma complexity, but its impact on Wine quality is still far from being satisfactory at the Winery level, mainly because it is easily replaced by S. cerevisiae yeasts during must fermentation. New T. delbrueckii killer strains were selected to overcome this problem. These strains killed S. cerevisiae yeasts and dominated fermentation better than T. delbrueckii non-killer strains when they were single-inoculated into crushed red grape must. All the T. delbrueckii Wines, but none of the S. cerevisiae Wines, underwent malolactic fermentation. Putative lactic acid bacteria were always found in the T. delbrueckii Wines, but none or very few in the S. cerevisiae Wines. Malic acid degradation was the greatest in the Wines inoculated with the killer strains, and these strains reached the greatest dominance ratios and had the slowest fermentation kinetics. The T. delbrueckii Wines had dried-fruit/pastry aromas, but low intensities of fresh-fruit aromas. The aroma differences between the T. delbrueckii and the S. cerevisiae Wines can be explained by the differences that were found in the amounts of some fruity aroma compounds such as isoamyl acetate, ethyl hexanoate, ethyl octanoate, and some lactones. This T. delbrueckii effect significantly raised the organoleptic quality scores of full-bodied Cabernet-Sauvignon red Wines inoculated with the killer strains. In particular, these Wines were judged as having excellent aroma complexity, mouth-feel, and sweetness.
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effects of new torulaspora delbrueckii killer yeasts on the must fermentation kinetics and aroma compounds of white Table Wine
Frontiers in Microbiology, 2015Co-Authors: Rocio Velazquez, Emiliano Zamora, Maria L Alvarez, Luis M Hernandez, Manuel RamirezAbstract:Torulaspora delbrueckii is becoming widely recommended for improving some specific characteristics of Wines. However, its impact on Wine quality is still far from satisfactory at the Winery level, mostly because it is easily replaced by S. cerevisiae-like yeasts during must fermentation. New T. delbrueckii killer strains were here isolated and selected for Winemaking. They killed S. cerevisiae yeasts and were able to dominate and complete the fermentation of sterile grape must. Sequential yeast inoculation of non-sterile white must with T. delbrueckii followed by S. cerevisiae did not ensure T. delbrueckii dominance or Wine quality improvement. Only a single initial must inoculation at high cell concentrations allowed the T. delbrueckii killer strains to dominate and complete the must fermentation to reach above 11% ethanol, but not the non-killer strains. None of the Wines underwent malolactic fermentation as long as the must had low turbidity and pH. Although no statistically significant differences were found in the Wine quality score, the S. cerevisiae-dominated Wines were preferred over the T. delbrueckii-dominated ones because the former had high-intensity fresh fruit aromas while the latter had lower intensity, but nevertheless nice and unusual dried fruit/pastry aromas. Except for ethyl propanoate and 3-ethoxy-1-propanol, which were more abundant in the T. delbrueckii–dominated Wines, most of the compounds with fresh fruit odour descriptors, including those with the greatest odour activity values (isoamyl acetate, ethyl hexanoate, and ethyl octanoate), were more abundant in the S. cerevisiae–dominated Wines. The low relative concentrations of these fruity compounds made it possible to detect in the T. delbrueckii–dominated Wines the low-relative-concentration compounds with dried fruit and pastry odours. An example was γ-ethoxy-butyrolactone which was significantly more abundant in these Wines than in those dominated by S. cerevisiae.
Piergiorgio Comuzzo - One of the best experts on this subject based on the ideXlab platform.
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Interactions between yeast autolysates and volatile compounds in Wine and model solution
Food chemistry, 2011Co-Authors: Piergiorgio Comuzzo, Lara Tat, Dennis Fenzi, Laura Brotto, Franco Battistutta, Roberto ZironiAbstract:The addition of a commercial yeast autolysate to a model solution of five typical Wine aroma compounds (ethyl octanoate, linalool, 2-phenylethanol, β-ionone and octanoic acid) was investigated considering different variables, such as temperature, pH and the presence of highly concentrated natural volatile substances in Wine (e.g. 3-methyl-1-butanol). The interactions of such compounds with both yeast walls and released colloids were studied using gas chromatography, with liquid-liquid extraction and solid-phase microextraction. The results were compared with those obtained by adding the commercial product to a white Table Wine, spiked with the five standard compounds. The data confirmed that yeast walls mainly bind less polar molecules: their loss in synthetic medium seemed to increase at higher pH values. Temperature and pH affected differently the interactions between yeast colloids and volatile compounds in Wine and model solution: in complex solutions (as the addition of 3-methyl-1-butanol demonstrated) the interaction mechanisms could be influenced by competitive or other matrix-related effects, which can reduce the binding of single compounds, or even enhance their volatility.
Luis M Hernandez - One of the best experts on this subject based on the ideXlab platform.
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influence of the dominance of must fermentation by torulaspora delbrueckii on the malolactic fermentation and organoleptic quality of red Table Wine
International Journal of Food Microbiology, 2016Co-Authors: Manuel Ramirez, Rocio Velazquez, Emiliano Zamora, Matilde Maqueda, Antonio Lopezpineiro, Luis M HernandezAbstract:Torulaspora delbrueckii can improve Wine aroma complexity, but its impact on Wine quality is still far from being satisfactory at the Winery level, mainly because it is easily replaced by S. cerevisiae yeasts during must fermentation. New T. delbrueckii killer strains were selected to overcome this problem. These strains killed S. cerevisiae yeasts and dominated fermentation better than T. delbrueckii non-killer strains when they were single-inoculated into crushed red grape must. All the T. delbrueckii Wines, but none of the S. cerevisiae Wines, underwent malolactic fermentation. Putative lactic acid bacteria were always found in the T. delbrueckii Wines, but none or very few in the S. cerevisiae Wines. Malic acid degradation was the greatest in the Wines inoculated with the killer strains, and these strains reached the greatest dominance ratios and had the slowest fermentation kinetics. The T. delbrueckii Wines had dried-fruit/pastry aromas, but low intensities of fresh-fruit aromas. The aroma differences between the T. delbrueckii and the S. cerevisiae Wines can be explained by the differences that were found in the amounts of some fruity aroma compounds such as isoamyl acetate, ethyl hexanoate, ethyl octanoate, and some lactones. This T. delbrueckii effect significantly raised the organoleptic quality scores of full-bodied Cabernet-Sauvignon red Wines inoculated with the killer strains. In particular, these Wines were judged as having excellent aroma complexity, mouth-feel, and sweetness.
-
effects of new torulaspora delbrueckii killer yeasts on the must fermentation kinetics and aroma compounds of white Table Wine
Frontiers in Microbiology, 2015Co-Authors: Rocio Velazquez, Emiliano Zamora, Maria L Alvarez, Luis M Hernandez, Manuel RamirezAbstract:Torulaspora delbrueckii is becoming widely recommended for improving some specific characteristics of Wines. However, its impact on Wine quality is still far from satisfactory at the Winery level, mostly because it is easily replaced by S. cerevisiae-like yeasts during must fermentation. New T. delbrueckii killer strains were here isolated and selected for Winemaking. They killed S. cerevisiae yeasts and were able to dominate and complete the fermentation of sterile grape must. Sequential yeast inoculation of non-sterile white must with T. delbrueckii followed by S. cerevisiae did not ensure T. delbrueckii dominance or Wine quality improvement. Only a single initial must inoculation at high cell concentrations allowed the T. delbrueckii killer strains to dominate and complete the must fermentation to reach above 11% ethanol, but not the non-killer strains. None of the Wines underwent malolactic fermentation as long as the must had low turbidity and pH. Although no statistically significant differences were found in the Wine quality score, the S. cerevisiae-dominated Wines were preferred over the T. delbrueckii-dominated ones because the former had high-intensity fresh fruit aromas while the latter had lower intensity, but nevertheless nice and unusual dried fruit/pastry aromas. Except for ethyl propanoate and 3-ethoxy-1-propanol, which were more abundant in the T. delbrueckii–dominated Wines, most of the compounds with fresh fruit odour descriptors, including those with the greatest odour activity values (isoamyl acetate, ethyl hexanoate, and ethyl octanoate), were more abundant in the S. cerevisiae–dominated Wines. The low relative concentrations of these fruity compounds made it possible to detect in the T. delbrueckii–dominated Wines the low-relative-concentration compounds with dried fruit and pastry odours. An example was γ-ethoxy-butyrolactone which was significantly more abundant in these Wines than in those dominated by S. cerevisiae.
