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Shao-quan Liu - One of the best experts on this subject based on the ideXlab platform.
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Modulation of grape wine flavor via the sequential inoculation of Williopsis saturnus and Saccharomyces cerevisiae
Food Biotechnology, 2017Co-Authors: Jannice Chew Hui Peh, Pin-rou Lee, Shao-quan LiuAbstract:ABSTRACTThe effects of the inoculum ratio of Williopsis saturnus var. saturnus NCYC22 and Saccharomyces cerevisiae var. bayanus EC-1118 at 1:200 and 1:800 on the chemical and volatile compositions of grape wine were studied in sequential fermentation. The grape juice was first inoculated with Williopsis (W.) saturnus for 9 d; thereafter, Saccharomyces (S.) cerevisiae was inoculated to continue the fermentation until d 19. The cell population of W. saturnus disappeared by d 13, with S. cerevisiae dominating until the end of the fermentation in both inoculum ratios. The changes in yeast count, pH, total soluble solids, sugars, organic acids, and amino acids were similar between the two inoculum ratios. A range of volatile compounds was formed, including alcohols, esters, fatty acids, aldehydes, and terpenes. There were significant differences between both inoculum ratios for medium-chain fatty acids (C8, C10, and C12), ethyl esters of fatty acids of C6, C10, C12, and C14 as well as isoamyl octanoate, while ...
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Modulation of grape wine flavor via the sequential inoculation of Williopsis saturnus and Saccharomyces cerevisiae
2017Co-Authors: Jannice Chew Hui Peh, Pin-rou Lee, Shao-quan LiuAbstract:The effects of the inoculum ratio of Williopsis saturnus var. saturnus NCYC22 and Saccharomyces cerevisiae var. bayanus EC-1118 at 1:200 and 1:800 on the chemical and volatile compositions of grape wine were studied in sequential fermentation. The grape juice was first inoculated with Williopsis (W.) saturnus for 9 d; thereafter, Saccharomyces (S.) cerevisiae was inoculated to continue the fermentation until d 19. The cell population of W. saturnus disappeared by d 13, with S. cerevisiae dominating until the end of the fermentation in both inoculum ratios. The changes in yeast count, pH, total soluble solids, sugars, organic acids, and amino acids were similar between the two inoculum ratios. A range of volatile compounds was formed, including alcohols, esters, fatty acids, aldehydes, and terpenes. There were significant differences between both inoculum ratios for medium-chain fatty acids (C8, C10, and C12), ethyl esters of fatty acids of C6, C10, C12, and C14 as well as isoamyl octanoate, while other volatiles were statistically the same.
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Summary
2016Co-Authors: Philip Curran, Shao-quan LiuAbstract:ratio is a critical factor for sequential fermentation of papaya wine by Williopsis saturnus and Saccharomyces cerevisia
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Evaluation of Beer Fermentation with a Novel Yeast Williopsis saturnus.
Food technology and biotechnology, 2016Co-Authors: Shao-quan Liu, Althea Ying Hui QuekAbstract:The aim of this study is to evaluate the potential of a novel yeast Williopsis saturnus var. mrakii NCYC 500 to produce fruity beer. Fermentation performance of W. mrakii and beer volatile composition were compared against that fermented with Saccharomyces cerevisiae Safale US-05. oBrix, sugar and pH differed significantly between the two types of beer. A total of 8 alcohols, 11 acids, 41 esters, 9 aldehydes, 8 ketones, 21 terpenes and terpenoids, 5 Maillard reaction products and 2 volatile phenolic compounds were detected. Yeast strain Safale US-05 was more capable of producing a wider range of ethyl and other esters, while yeast strain NCYC 500 produced significantly higher amounts of acetate esters. Strain NCYC 500 retained more terpenes and terpenoids, suggesting that the resultant beer could possess more of the aromatic hint of hops. This study showed that W. saturnus var. mrakii NCYC 500 could ferment wort to produce low-alcohol beer with higher levels of acetate esters, terpenes and terpenoids than yeast S. cerevisiae Safale US-05.
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Cider fermentation with three Williopsis saturnus yeast strains and volatile changes
Annals of Microbiology, 2014Co-Authors: Ma Thandar Aung, Pin-rou Lee, Shao-quan LiuAbstract:Williopsis saturnus var. subsufficiens NCYC 2728, W. saturnus var. saturnus NCYC 22 and W. saturnus var. mrakii NCYC 500 were used to carry out cider fermentation to assess their impact on the volatile composition of cider. The changes of yeast cell population, °Brix and pH were similar among the three yeasts. Strain NCYC 500 grew best, with the highest cell population of 1.14 × 108 CFU ml−1, followed by strains NCYC 2728 and NCYC 22 (8 × 107 CFU ml−1 and 3.19 × 107 CFU ml−1 respectively). Esters were the most abundant volatiles produced, followed by alcohols. Among the esters, ethyl acetate, 2-phenylethyl acetate, isoamyl acetate, cis-3-hexenyl acetate and hexyl acetate were the major volatiles. The major alcohols were ethanol, isoamyl alcohol, 2-phenylethyl alcohol and isobutyl alcohol. The three Williopsis yeasts transformed volatile compounds during cider fermentation with significant variations in terms of volatile production and degradation. This study implied that fermentation with Williopsis yeasts could result in cider with a more complex yet fruity aroma.
G.i. Naumov - One of the best experts on this subject based on the ideXlab platform.
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Molecular genetic polymorphism of soil yeasts of the genus Williopsis from Taiwan Island
Russian Journal of Genetics, 2017Co-Authors: E.s. Naumova, Ch.-fu Lee, V. I. Kondratieva, A. Zh. Sadykova, G.i. NaumovAbstract:Comparative molecular genetic study of Williopsis yeasts isolated in different world regions reveals some peculiarities of species content in Taiwan. Some Williopsis yeasts may represent novel species. In Taiwan, four of the five known Williopsis species are documented: W. saturnus , W. suaveolens , W. mrakii , and W. subsufficiens . The W. saturnus yeasts predominate in Taiwanese soils, while W. suaveolens is more frequently isolated in Europe.
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Molecular divergence of the soil yeasts Williopsis sensu stricto
Microbiology, 2004Co-Authors: E.s. Naumova, D O Gazdiev, G.i. NaumovAbstract:Fifty-three strains of Saturn-spored yeasts were analyzed by means of restriction analysis of the amplified fragment of rDNA comprising the 5.8S rRNA gene and the internal transcribed spacers ITS1 and ITS2. The use of endonucleases Hae III and Msp I enabled clear differentiation of yeast species Williopsis mucosa, W. salicorniae, ZygoWilliopsis californica , and Komagataea pratensis and the Williopsis sensu stricto complex. The minisatellite primer M13 was proposed for differentiation between sibling species of Williopsis sensu stricto, which have identical restriction profiles. PCR with primer M13 enabled reidentification of a number of collection strains, species identification of Saturn-spored isolates from the Far East, and detection of three strains affiliated to novel taxa. The latter have unique PCR profiles and differ in the nucleotide sequences of ITS1 and ITS2 fragments of rDNA. Possible variations in the results obtained with different molecular methods are discussed.
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Differentiation of the yeasts Williopsis, ZygoWilliopsis and Komagataea by karyotypic and PCR analyses.
Systematic and applied microbiology, 2004Co-Authors: E.s. Naumova, G.i. Naumov, Jozef Nosek, Lubomir TomaskaAbstract:Summary We used polymerase chain reaction with universal and microsatellite primers, and molecular karyotyping to evaluate the extent of divergence between the genomes of the yeasts currently assigned to the heterogeneous genus Williopsis . Pulsed-field gel electrophoresis of chromosomal DNAs indicates that ZygoWilliopsis californica, Komagataea pratensis, Williopsis mucosa, Williopsis salicorniae species and Williopsis sensu stricto complex have clearly different karyotypes. In contrast, the latter six species, Williopsis saturnus, W. beijerinckii, W. mrakii, W. suaveolens, W. subsufficiens and W. sargentensis , show similar banding patterns and practically cannot be differentiated on the basis of their karyotypes. The data revealed that a PCR method employing the universal primer N21 is appropriate for the distinction of Williopsis, ZygoWilliopsis and Komagataea yeasts. Unique fingerprints were generated with this primer for all 10 species studied while strains of the same species showed nearly identical profiles. The data of UP-PCR are in good agreement with genetic classification and provide support for the species status of the yeasts composing the Williopsis sensu stricto complex. Microsatellite primer (GTG) 5 allowing molecular typing of individual strains of the same species may be useful for investigating population structure of the saturn-spored yeasts.
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Molecular divergence of the soil yeasts Williopsis sensu stricto
Mikrobiologiia, 2004Co-Authors: E.s. Naumova, D O Gazdiev, G.i. NaumovAbstract:Fifty-three strains of saturn-spored yeasts were analyzed by means of restriction analysis of the amplified fragment of rDNA which comprised the 5.8S rRNA gene and the internal transcribed spacers ITS1 and ITS2. The use of endonucleases HaeIII and MspI enabled clear differentiation of yeast species Williopsis mucosa, W. salicorniae, ZygoWilliopsis californica, Komagataea pratensis, and the Williopsis sensu stricto complex. Minisatellite primer M13 was proposed for the differentiation between twin species of Williopsis sensu stricto, which have identical restriction profiles. PCR with primer M13 enabled reidentification of a number of collection strains, species identification of saturn-spored isolates from the Far East, and detection of three strains affiliated to novel taxa. The latter have unique PCR profiles and differ in the nucleotide sequences of ITS1 and ITS2 fragments of rDNA. Possible variations in the results obtained with different molecular methods are discussed.
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Identification of ZygoWilliopsis californicaStrains of Different Origin by Means of Polymerase Chain Reaction with Universal Primers
Microbiology, 2001Co-Authors: N G Tokareva, E.s. Naumova, I. P. Bab'eva, G.i. NaumovAbstract:After reevaluation of the taxonomic position of 27 yeast collection strains of different origin by UP-PCR followed by dot-hybridization, only 22 strains were assigned to the biological species ZygoWilliopsis californica(Lodder) Kudriavzev. Four strains were identified as Williopsis suaveolens(Klocker) Naumov et al. Universal primers L45 and N21 are recommended for identification of the Z. californicayeasts.
E.s. Naumova - One of the best experts on this subject based on the ideXlab platform.
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Molecular genetic polymorphism of soil yeasts of the genus Williopsis from Taiwan Island
Russian Journal of Genetics, 2017Co-Authors: E.s. Naumova, Ch.-fu Lee, V. I. Kondratieva, A. Zh. Sadykova, G.i. NaumovAbstract:Comparative molecular genetic study of Williopsis yeasts isolated in different world regions reveals some peculiarities of species content in Taiwan. Some Williopsis yeasts may represent novel species. In Taiwan, four of the five known Williopsis species are documented: W. saturnus , W. suaveolens , W. mrakii , and W. subsufficiens . The W. saturnus yeasts predominate in Taiwanese soils, while W. suaveolens is more frequently isolated in Europe.
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Molecular divergence of the soil yeasts Williopsis sensu stricto
Microbiology, 2004Co-Authors: E.s. Naumova, D O Gazdiev, G.i. NaumovAbstract:Fifty-three strains of Saturn-spored yeasts were analyzed by means of restriction analysis of the amplified fragment of rDNA comprising the 5.8S rRNA gene and the internal transcribed spacers ITS1 and ITS2. The use of endonucleases Hae III and Msp I enabled clear differentiation of yeast species Williopsis mucosa, W. salicorniae, ZygoWilliopsis californica , and Komagataea pratensis and the Williopsis sensu stricto complex. The minisatellite primer M13 was proposed for differentiation between sibling species of Williopsis sensu stricto, which have identical restriction profiles. PCR with primer M13 enabled reidentification of a number of collection strains, species identification of Saturn-spored isolates from the Far East, and detection of three strains affiliated to novel taxa. The latter have unique PCR profiles and differ in the nucleotide sequences of ITS1 and ITS2 fragments of rDNA. Possible variations in the results obtained with different molecular methods are discussed.
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Differentiation of the yeasts Williopsis, ZygoWilliopsis and Komagataea by karyotypic and PCR analyses.
Systematic and applied microbiology, 2004Co-Authors: E.s. Naumova, G.i. Naumov, Jozef Nosek, Lubomir TomaskaAbstract:Summary We used polymerase chain reaction with universal and microsatellite primers, and molecular karyotyping to evaluate the extent of divergence between the genomes of the yeasts currently assigned to the heterogeneous genus Williopsis . Pulsed-field gel electrophoresis of chromosomal DNAs indicates that ZygoWilliopsis californica, Komagataea pratensis, Williopsis mucosa, Williopsis salicorniae species and Williopsis sensu stricto complex have clearly different karyotypes. In contrast, the latter six species, Williopsis saturnus, W. beijerinckii, W. mrakii, W. suaveolens, W. subsufficiens and W. sargentensis , show similar banding patterns and practically cannot be differentiated on the basis of their karyotypes. The data revealed that a PCR method employing the universal primer N21 is appropriate for the distinction of Williopsis, ZygoWilliopsis and Komagataea yeasts. Unique fingerprints were generated with this primer for all 10 species studied while strains of the same species showed nearly identical profiles. The data of UP-PCR are in good agreement with genetic classification and provide support for the species status of the yeasts composing the Williopsis sensu stricto complex. Microsatellite primer (GTG) 5 allowing molecular typing of individual strains of the same species may be useful for investigating population structure of the saturn-spored yeasts.
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Molecular divergence of the soil yeasts Williopsis sensu stricto
Mikrobiologiia, 2004Co-Authors: E.s. Naumova, D O Gazdiev, G.i. NaumovAbstract:Fifty-three strains of saturn-spored yeasts were analyzed by means of restriction analysis of the amplified fragment of rDNA which comprised the 5.8S rRNA gene and the internal transcribed spacers ITS1 and ITS2. The use of endonucleases HaeIII and MspI enabled clear differentiation of yeast species Williopsis mucosa, W. salicorniae, ZygoWilliopsis californica, Komagataea pratensis, and the Williopsis sensu stricto complex. Minisatellite primer M13 was proposed for the differentiation between twin species of Williopsis sensu stricto, which have identical restriction profiles. PCR with primer M13 enabled reidentification of a number of collection strains, species identification of saturn-spored isolates from the Far East, and detection of three strains affiliated to novel taxa. The latter have unique PCR profiles and differ in the nucleotide sequences of ITS1 and ITS2 fragments of rDNA. Possible variations in the results obtained with different molecular methods are discussed.
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Identification of ZygoWilliopsis californicaStrains of Different Origin by Means of Polymerase Chain Reaction with Universal Primers
Microbiology, 2001Co-Authors: N G Tokareva, E.s. Naumova, I. P. Bab'eva, G.i. NaumovAbstract:After reevaluation of the taxonomic position of 27 yeast collection strains of different origin by UP-PCR followed by dot-hybridization, only 22 strains were assigned to the biological species ZygoWilliopsis californica(Lodder) Kudriavzev. Four strains were identified as Williopsis suaveolens(Klocker) Naumov et al. Universal primers L45 and N21 are recommended for identification of the Z. californicayeasts.
Pin-rou Lee - One of the best experts on this subject based on the ideXlab platform.
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Modulation of grape wine flavor via the sequential inoculation of Williopsis saturnus and Saccharomyces cerevisiae
Food Biotechnology, 2017Co-Authors: Jannice Chew Hui Peh, Pin-rou Lee, Shao-quan LiuAbstract:ABSTRACTThe effects of the inoculum ratio of Williopsis saturnus var. saturnus NCYC22 and Saccharomyces cerevisiae var. bayanus EC-1118 at 1:200 and 1:800 on the chemical and volatile compositions of grape wine were studied in sequential fermentation. The grape juice was first inoculated with Williopsis (W.) saturnus for 9 d; thereafter, Saccharomyces (S.) cerevisiae was inoculated to continue the fermentation until d 19. The cell population of W. saturnus disappeared by d 13, with S. cerevisiae dominating until the end of the fermentation in both inoculum ratios. The changes in yeast count, pH, total soluble solids, sugars, organic acids, and amino acids were similar between the two inoculum ratios. A range of volatile compounds was formed, including alcohols, esters, fatty acids, aldehydes, and terpenes. There were significant differences between both inoculum ratios for medium-chain fatty acids (C8, C10, and C12), ethyl esters of fatty acids of C6, C10, C12, and C14 as well as isoamyl octanoate, while ...
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Modulation of grape wine flavor via the sequential inoculation of Williopsis saturnus and Saccharomyces cerevisiae
2017Co-Authors: Jannice Chew Hui Peh, Pin-rou Lee, Shao-quan LiuAbstract:The effects of the inoculum ratio of Williopsis saturnus var. saturnus NCYC22 and Saccharomyces cerevisiae var. bayanus EC-1118 at 1:200 and 1:800 on the chemical and volatile compositions of grape wine were studied in sequential fermentation. The grape juice was first inoculated with Williopsis (W.) saturnus for 9 d; thereafter, Saccharomyces (S.) cerevisiae was inoculated to continue the fermentation until d 19. The cell population of W. saturnus disappeared by d 13, with S. cerevisiae dominating until the end of the fermentation in both inoculum ratios. The changes in yeast count, pH, total soluble solids, sugars, organic acids, and amino acids were similar between the two inoculum ratios. A range of volatile compounds was formed, including alcohols, esters, fatty acids, aldehydes, and terpenes. There were significant differences between both inoculum ratios for medium-chain fatty acids (C8, C10, and C12), ethyl esters of fatty acids of C6, C10, C12, and C14 as well as isoamyl octanoate, while other volatiles were statistically the same.
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Cider fermentation with three Williopsis saturnus yeast strains and volatile changes
Annals of Microbiology, 2014Co-Authors: Ma Thandar Aung, Pin-rou Lee, Shao-quan LiuAbstract:Williopsis saturnus var. subsufficiens NCYC 2728, W. saturnus var. saturnus NCYC 22 and W. saturnus var. mrakii NCYC 500 were used to carry out cider fermentation to assess their impact on the volatile composition of cider. The changes of yeast cell population, °Brix and pH were similar among the three yeasts. Strain NCYC 500 grew best, with the highest cell population of 1.14 × 108 CFU ml−1, followed by strains NCYC 2728 and NCYC 22 (8 × 107 CFU ml−1 and 3.19 × 107 CFU ml−1 respectively). Esters were the most abundant volatiles produced, followed by alcohols. Among the esters, ethyl acetate, 2-phenylethyl acetate, isoamyl acetate, cis-3-hexenyl acetate and hexyl acetate were the major volatiles. The major alcohols were ethanol, isoamyl alcohol, 2-phenylethyl alcohol and isobutyl alcohol. The three Williopsis yeasts transformed volatile compounds during cider fermentation with significant variations in terms of volatile production and degradation. This study implied that fermentation with Williopsis yeasts could result in cider with a more complex yet fruity aroma.
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Effect of Precursors on Volatile Compounds in Papaya Wine Fermented by Mixed Yeasts
University of Zagreb, 2013Co-Authors: Pin-rou Lee, Philip Curran, Irene Siew-may Chong, Shao-quan LiuAbstract:The impact of the addition of fusel oil or amino acids on the volatile compounds in papaya wine fermented with a mixed culture of Saccharomyces cerevisiae var. bayanus R2 and Williopsis saturnus var. mrakii NCYC 2251 at a ratio of 1:1000 was studied. Fusel oil addition increased the fraction of alcohols and promoted the production of isoamyl octanoate, isoamyl decanoate and isobutyl decanoate, while decreased the fraction of ethyl acetate and 2-phenylethyl acetate. The addition of amino acids enhanced the formation of total volatile fatty acids, 2-phenylethanol and some ethyl esters. The papaya wine with added amino acids possessed more acidic and buttery notes than the control, while that with added fusel oil had an overall aroma profile comparable to that of the control. This study suggests that papaya juice fermentation with mixed yeasts in conjunction with the added fusel oil or selected amino acids may be another method of modulating the flavour of papaya wine
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Yeast ratio is a critical factor for sequential fermentation of papaya wine by Williopsis saturnus and Saccharomyces cerevisiae
Microbial biotechnology, 2012Co-Authors: Pin-rou Lee, Philip Curran, Stephanie Hui Chern Kho, Shao-quan LiuAbstract:Summary The growth kinetics and fermentation performance of Williopsis saturnus and Saccharomyces cerevisiae at ratios of 10:1, 1:1 and 1:10 (W.:S.) were studied in papaya juice with initial 7-day fermentation by W. saturnus, followed by S. cerevisiae. The growth kinetics of W. saturnus were similar at all ratios, but its maximum cell count decreased as the proportion of S. cerevisiae was increased. Conversely, there was an early death of S. cerevisiae at the ratio of 10:1. Williopsis saturnus was the dominant yeast at 10:1 ratio that produced papaya wine with elevated concentrations of acetate esters. On the other hand, 1:1 and 1:10 ratios allowed the coexistence of both yeasts which enabled the flavour-enhancing potential of W. saturnus as well as the ethyl ester and alcohol-producing abilities of S. cerevisiae. In particular, 1:1 and 1:10 ratios resulted in production of more ethyl esters, alcohols and 2-phenylethyl acetate. However, the persistence of both yeasts at 1:1 and 1:10 ratios led to formation of high levels of acetic acid. The findings suggest that yeast ratio is a critical factor for sequential fermentation of papaya wine by W. saturnus and S. cerevisiae as a strategy to modulate papaya wine flavour.
Philip Curran - One of the best experts on this subject based on the ideXlab platform.
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Summary
2016Co-Authors: Philip Curran, Shao-quan LiuAbstract:ratio is a critical factor for sequential fermentation of papaya wine by Williopsis saturnus and Saccharomyces cerevisia
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Influence of Saccharomyces cerevisiae and Williopsis saturnus var. Mrakii on mango wine characteristics
Acta Alimentaria, 2014Co-Authors: L. Chan, Philip Curran, S.-q. LiuAbstract:Saccharomyces cerevisiae MERIT.ferm was used as mono- and mixed-cultures with Williopsis saturnus var. mrakii NCYC500 in mango wine fermentation. A ratio of 1:1000 (Saccharomyces:Williopsis) was chosen for mixed-culture fermentation to enable longer persistence of the latter. The monoculture of S. cerevisiae and mixed-culture was able to ferment to dryness with 7.0% and 7.7% ethanol, respectively. The monoculture of W. mrakii produced 1.45% ethanol. The mango wines fermented by S. cerevisiae alone and the mixed-culture were more yeasty and winey, which reflected their higher amounts of fusel alcohols, ethyl esters and medium-chain fatty acids. The mango wine fermented by W. mrakii alone was much less alcoholic, but fruitier, sweeter, which corresponded to its higher levels of acetate esters.
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Effect of Precursors on Volatile Compounds in Papaya Wine Fermented by Mixed Yeasts
University of Zagreb, 2013Co-Authors: Pin-rou Lee, Philip Curran, Irene Siew-may Chong, Shao-quan LiuAbstract:The impact of the addition of fusel oil or amino acids on the volatile compounds in papaya wine fermented with a mixed culture of Saccharomyces cerevisiae var. bayanus R2 and Williopsis saturnus var. mrakii NCYC 2251 at a ratio of 1:1000 was studied. Fusel oil addition increased the fraction of alcohols and promoted the production of isoamyl octanoate, isoamyl decanoate and isobutyl decanoate, while decreased the fraction of ethyl acetate and 2-phenylethyl acetate. The addition of amino acids enhanced the formation of total volatile fatty acids, 2-phenylethanol and some ethyl esters. The papaya wine with added amino acids possessed more acidic and buttery notes than the control, while that with added fusel oil had an overall aroma profile comparable to that of the control. This study suggests that papaya juice fermentation with mixed yeasts in conjunction with the added fusel oil or selected amino acids may be another method of modulating the flavour of papaya wine
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Yeast ratio is a critical factor for sequential fermentation of papaya wine by Williopsis saturnus and Saccharomyces cerevisiae
Microbial biotechnology, 2012Co-Authors: Pin-rou Lee, Philip Curran, Stephanie Hui Chern Kho, Shao-quan LiuAbstract:Summary The growth kinetics and fermentation performance of Williopsis saturnus and Saccharomyces cerevisiae at ratios of 10:1, 1:1 and 1:10 (W.:S.) were studied in papaya juice with initial 7-day fermentation by W. saturnus, followed by S. cerevisiae. The growth kinetics of W. saturnus were similar at all ratios, but its maximum cell count decreased as the proportion of S. cerevisiae was increased. Conversely, there was an early death of S. cerevisiae at the ratio of 10:1. Williopsis saturnus was the dominant yeast at 10:1 ratio that produced papaya wine with elevated concentrations of acetate esters. On the other hand, 1:1 and 1:10 ratios allowed the coexistence of both yeasts which enabled the flavour-enhancing potential of W. saturnus as well as the ethyl ester and alcohol-producing abilities of S. cerevisiae. In particular, 1:1 and 1:10 ratios resulted in production of more ethyl esters, alcohols and 2-phenylethyl acetate. However, the persistence of both yeasts at 1:1 and 1:10 ratios led to formation of high levels of acetic acid. The findings suggest that yeast ratio is a critical factor for sequential fermentation of papaya wine by W. saturnus and S. cerevisiae as a strategy to modulate papaya wine flavour.
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Impact of two Williopsis yeast strains on the volatile composition of mango wine
International Journal of Food Science & Technology, 2012Co-Authors: Philip Curran, Shao-quan LiuAbstract:Summary The aim of the research was to study the volatile composition of mango wine fermented with two Williopsis yeast strains: Williopsis saturnus var. mrakii NCYC500 and W. staurnus var. suaveolens NCYC2586. Thirty terpenoids, twenty-six esters, ten alcohols, nine acids, seven aldehydes and ketones, two ethers, two phenols and one sulphur compound were identified in the mango wine fermented with strain NCYC500, while twenty-seven terpenoids, thirty esters, eleven alcohols, eight acids, eight aldehydes and ketones, three ethers, two phenols, one sulphur compound and one furan were detected in the mango wine fermented with the strain NCYC2586. The kinetic changes, final concentrations and odour activity values of major volatiles were compared between the two Williopsis yeast strains and also with other yeast reported in the literature. The results showed that Williopsis yeast strains NCYC500 and NCYC2586 were high producers of acetic acid and acetate esters, but low producers of medium- to long-chain fatty acids and their corresponding ethyl esters. Unlike mango wine fermented with Saccharomyces cerevisiae, most terpenoids derived from mango juice were retained in the resultant mango wine fermented with the two Williopsis yeast strains, suggesting the mango wine could retain the aromatic hints of fresh mango.
