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Heinisch JJ, Murra A, Fernández Murillo L, Schmitz HP. The Role of Glucose-6-phosphate Dehydrogenase in the Wine Yeast Hanseniaspora uvarum. Int J Mol Sci 2024; 25:2395. [PMID: 38397078 PMCID: PMC10889316 DOI: 10.3390/ijms25042395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 02/13/2024] [Accepted: 02/16/2024] [Indexed: 02/25/2024] Open
Abstract
Hanseniaspora uvarum is the predominant yeast species in the majority of wine fermentations, which has only recently become amenable to directed genetic manipulation. The genetics and metabolism of H. uvarum have been poorly studied as compared to other yeasts of biotechnological importance. This work describes the construction and characterization of homozygous deletion mutants in the HuZWF1 gene, encoding glucose-6-phosphate dehydrogenase (G6PDH), which provides the entrance into the oxidative part of the pentose phosphate pathway (PPP) and serves as a major source of NADPH for anabolic reactions and oxidative stress response. Huzwf1 deletion mutants grow more slowly on glucose medium than wild-type and are hypersensitive both to hydrogen peroxide and potassium bisulfite, indicating that G6PDH activity is required to cope with these stresses. The mutant also requires methionine for growth. Enzyme activity can be restored by the expression of heterologous G6PDH genes from other yeasts and humans under the control of a strong endogenous promoter. These findings provide the basis for a better adaptation of H. uvarum to conditions used in wine fermentations, as well as its use for other biotechnological purposes and as an expression organism for studying G6PDH functions in patients with hemolytic anemia.
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Affiliation(s)
- Jürgen J. Heinisch
- AG Genetik, Fachbereich Biologie/Chemie, Universität Osnabrück, Barbarastr. 11, D-49076 Osnabrück, Germany; (A.M.); (L.F.M.); (H.-P.S.)
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Nobis A, Kwasnicki M, Lehnhardt F, Hellwig M, Henle T, Becker T, Gastl M. A Comprehensive Evaluation of Flavor Instability of Beer (Part 2): The Influence of De Novo Formation of Aging Aldehydes. Foods 2021; 10:foods10112668. [PMID: 34828949 PMCID: PMC8622366 DOI: 10.3390/foods10112668] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 10/28/2021] [Accepted: 11/01/2021] [Indexed: 11/16/2022] Open
Abstract
Flavor instability of beer is affected by the rise of aroma-active aldehydes during aging. Aldehydes can be either released from bound-state forms or formed de novo. This second part of our study focused on the de novo formation of aldehydes during the Maillard reaction, Strecker degradation, and oxidation reactions. Key precursor compounds for de novo pathways are free amino acids. This study varied the potential for reactions by varying free amino acid content in fresh beer using different proteolytic malt modification levels (569–731 mg/100 g d. m. of soluble nitrogen) of the used malt in brewing trials. Overall, six pale lager beers were produced from three malts (different malt modification levels), each was made from two different barley varieties and was naturally and forcibly aged. It was found that higher malt modification levels in fresh beer and during beer aging increased amino acid and dicarbonyl concentrations as aging precursors and Strecker aldehyde contents as aging indicators. Dicarbonyls were degraded during aging. Advanced glycation end products as possible degradation products showed no consistent formation during aging. Therefore, Strecker reactions were favored during beer aging. No alternative oxidative formation of Strecker aldehydes from their corresponding alcohols could be confirmed. Along with the preceding part one of our investigation, the results of this study showed that de novo formation and release occur simultaneously. After 4 months of natural aging, aldehyde rise is mainly accounted for by de novo formation.
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Affiliation(s)
- Arndt Nobis
- TUM School of Life Sciences, Technische Universität München, 85354 Freising, Germany; (A.N.); (F.L.); (T.B.)
| | - Melanie Kwasnicki
- Chair of Food Chemistry, Technische Universität Dresden, 01069 Dresden, Germany; (M.K.); (T.H.)
| | - Florian Lehnhardt
- TUM School of Life Sciences, Technische Universität München, 85354 Freising, Germany; (A.N.); (F.L.); (T.B.)
| | - Michael Hellwig
- Institute of Food Chemistry, Technical University of Braunschweig, 38106 Braunschweig, Germany;
| | - Thomas Henle
- Chair of Food Chemistry, Technische Universität Dresden, 01069 Dresden, Germany; (M.K.); (T.H.)
| | - Thomas Becker
- TUM School of Life Sciences, Technische Universität München, 85354 Freising, Germany; (A.N.); (F.L.); (T.B.)
| | - Martina Gastl
- TUM School of Life Sciences, Technische Universität München, 85354 Freising, Germany; (A.N.); (F.L.); (T.B.)
- Correspondence:
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Methanol Mitigation during Manufacturing of Fruit Spirits with Special Consideration of Novel Coffee Cherry Spirits. Molecules 2021; 26:molecules26092585. [PMID: 33925245 PMCID: PMC8125215 DOI: 10.3390/molecules26092585] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/20/2021] [Accepted: 04/23/2021] [Indexed: 11/17/2022] Open
Abstract
Methanol is a natural ingredient with major occurrence in fruit spirits, such as apple, pear, plum or cherry spirits, but also in spirits made from coffee pulp. The compound is formed during fermentation and the following mash storage by enzymatic hydrolysis of naturally present pectins. Methanol is toxic above certain threshold levels and legal limits have been set in most jurisdictions. Therefore, the methanol content needs to be mitigated and its level must be controlled. This article will review the several factors that influence the methanol content including the pH value of the mash, the addition of various yeast and enzyme preparations, fermentation temperature, mash storage, and most importantly the raw material quality and hygiene. From all these mitigation possibilities, lowering the pH value and the use of cultured yeasts when mashing fruit substances is already common as best practice today. Also a controlled yeast fermentation at acidic pH facilitates not only reduced methanol formation, but ultimately also leads to quality benefits of the distillate. Special care has to be observed in the case of spirits made from coffee by-products which are prone to spoilage with very high methanol contents reported in past studies.
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Pandey AK, Kumar M, Kumari S, Kumari P, Yusuf F, Jakeer S, Naz S, Chandna P, Bhatnagar I, Gaur NA. Evaluation of divergent yeast genera for fermentation-associated stresses and identification of a robust sugarcane distillery waste isolate Saccharomyces cerevisiae NGY10 for lignocellulosic ethanol production in SHF and SSF. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:40. [PMID: 30858877 PMCID: PMC6391804 DOI: 10.1186/s13068-019-1379-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 02/15/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Lignocellulosic hydrolysates contain a mixture of hexose (C6)/pentose (C5) sugars and pretreatment-generated inhibitors (furans, weak acids and phenolics). Therefore, robust yeast isolates with characteristics of C6/C5 fermentation and tolerance to pretreatment-derived inhibitors are pre-requisite for efficient lignocellulosic material based biorefineries. Moreover, use of thermotolerant yeast isolates will further reduce cooling cost, contamination during fermentation, and required for developing simultaneous saccharification and fermentation (SSF), simultaneous saccharification and co-fermentation (SScF), and consolidated bio-processing (CBP) strategies. RESULTS In this study, we evaluated thirty-five yeast isolates (belonging to six genera including Saccharomyces, Kluyveromyces, Candida, Scheffersomyces, Ogatea and Wickerhamomyces) for pretreatment-generated inhibitors {furfural, 5-hydroxymethyl furfural (5-HMF) and acetic acid} and thermotolerant phenotypes along with the fermentation performances at 40 °C. Among them, a sugarcane distillery waste isolate, Saccharomyces cerevisiae NGY10 produced maximum 49.77 ± 0.34 g/l and 46.81 ± 21.98 g/l ethanol with the efficiency of 97.39% and 93.54% at 30 °C and 40 °C, respectively, in 24 h using glucose as a carbon source. Furthermore, isolate NGY10 produced 12.25 ± 0.09 g/l and 7.18 ± 0.14 g/l of ethanol with 92.81% and 91.58% efficiency via SHF, and 30.22 g/l and 25.77 g/l ethanol with 86.43% and 73.29% efficiency via SSF using acid- and alkali-pretreated rice straw as carbon sources, respectively, at 40 °C. In addition, isolate NGY10 also produced 92.31 ± 3.39 g/l (11.7% v/v) and 33.66 ± 1.04 g/l (4.26% v/v) ethanol at 40 °C with the yields of 81.49% and 73.87% in the presence of 30% w/v glucose or 4× concentrated acid-pretreated rice straw hydrolysate, respectively. Moreover, isolate NGY10 displayed furfural- (1.5 g/l), 5-HMF (3.0 g/l), acetic acid- (0.2% v/v) and ethanol-(10.0% v/v) tolerant phenotypes. CONCLUSION A sugarcane distillery waste isolate NGY10 demonstrated high potential for ethanol production, C5 metabolic engineering and developing strategies for SSF, SScF and CBP.
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Affiliation(s)
- Ajay Kumar Pandey
- Yeast Biofuel Group, DBT-ICGEB Center for Advanced Bioenergy Research, International Center for Genetic Engineering and Biotechnology (ICGEB), New Delhi, 110067 India
| | - Mohit Kumar
- Yeast Biofuel Group, DBT-ICGEB Center for Advanced Bioenergy Research, International Center for Genetic Engineering and Biotechnology (ICGEB), New Delhi, 110067 India
| | - Sonam Kumari
- Yeast Biofuel Group, DBT-ICGEB Center for Advanced Bioenergy Research, International Center for Genetic Engineering and Biotechnology (ICGEB), New Delhi, 110067 India
| | - Priya Kumari
- Yeast Biofuel Group, DBT-ICGEB Center for Advanced Bioenergy Research, International Center for Genetic Engineering and Biotechnology (ICGEB), New Delhi, 110067 India
| | - Farnaz Yusuf
- Yeast Biofuel Group, DBT-ICGEB Center for Advanced Bioenergy Research, International Center for Genetic Engineering and Biotechnology (ICGEB), New Delhi, 110067 India
| | - Shaik Jakeer
- Yeast Biofuel Group, DBT-ICGEB Center for Advanced Bioenergy Research, International Center for Genetic Engineering and Biotechnology (ICGEB), New Delhi, 110067 India
| | - Sumera Naz
- Yeast Biofuel Group, DBT-ICGEB Center for Advanced Bioenergy Research, International Center for Genetic Engineering and Biotechnology (ICGEB), New Delhi, 110067 India
| | - Piyush Chandna
- Yeast Biofuel Group, DBT-ICGEB Center for Advanced Bioenergy Research, International Center for Genetic Engineering and Biotechnology (ICGEB), New Delhi, 110067 India
| | - Ishita Bhatnagar
- Yeast Biofuel Group, DBT-ICGEB Center for Advanced Bioenergy Research, International Center for Genetic Engineering and Biotechnology (ICGEB), New Delhi, 110067 India
| | - Naseem A. Gaur
- Yeast Biofuel Group, DBT-ICGEB Center for Advanced Bioenergy Research, International Center for Genetic Engineering and Biotechnology (ICGEB), New Delhi, 110067 India
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Glycolytic Functions Are Conserved in the Genome of the Wine Yeast Hanseniaspora uvarum, and Pyruvate Kinase Limits Its Capacity for Alcoholic Fermentation. Appl Environ Microbiol 2017; 83:AEM.01580-17. [PMID: 28887422 DOI: 10.1128/aem.01580-17] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 09/03/2017] [Indexed: 01/11/2023] Open
Abstract
Hanseniaspora uvarum (anamorph Kloeckera apiculata) is a predominant yeast on wine grapes and other fruits and has a strong influence on wine quality, even when Saccharomyces cerevisiae starter cultures are employed. In this work, we sequenced and annotated approximately 93% of the H. uvarum genome. Southern and synteny analyses were employed to construct a map of the seven chromosomes present in a type strain. Comparative determinations of specific enzyme activities within the fermentative pathway in H. uvarum and S. cerevisiae indicated that the reduced capacity of the former yeast for ethanol production is caused primarily by an ∼10-fold-lower activity of the key glycolytic enzyme pyruvate kinase. The heterologous expression of the encoding gene, H. uvarumPYK1 (HuPYK1), and two genes encoding the phosphofructokinase subunits, HuPFK1 and HuPFK2, in the respective deletion mutants of S. cerevisiae confirmed their functional homology.IMPORTANCEHanseniaspora uvarum is a predominant yeast species on grapes and other fruits. It contributes significantly to the production of desired as well as unfavorable aroma compounds and thus determines the quality of the final product, especially wine. Despite this obvious importance, knowledge on its genetics is scarce. As a basis for targeted metabolic modifications, here we provide the results of a genomic sequencing approach, including the annotation of 3,010 protein-encoding genes, e.g., those encoding the entire sugar fermentation pathway, key components of stress response signaling pathways, and enzymes catalyzing the production of aroma compounds. Comparative analyses suggest that the low fermentative capacity of H. uvarum compared to that of Saccharomyces cerevisiae can be attributed to low pyruvate kinase activity. The data reported here are expected to aid in establishing H. uvarum as a non-Saccharomyces yeast in starter cultures for wine and cider fermentations.
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Influence of various yeast strains and selected starchy raw materials on production of higher alcohols during the alcoholic fermentation process. Eur Food Res Technol 2014. [DOI: 10.1007/s00217-014-2323-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Fischer S, Procopio S, Becker T. Self-cloning brewing yeast: a new dimension in beverage production. Eur Food Res Technol 2013. [DOI: 10.1007/s00217-013-2092-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Nijkamp JF, van den Broek M, Datema E, de Kok S, Bosman L, Luttik MA, Daran-Lapujade P, Vongsangnak W, Nielsen J, Heijne WHM, Klaassen P, Paddon CJ, Platt D, Kötter P, van Ham RC, Reinders MJT, Pronk JT, de Ridder D, Daran JM. De novo sequencing, assembly and analysis of the genome of the laboratory strain Saccharomyces cerevisiae CEN.PK113-7D, a model for modern industrial biotechnology. Microb Cell Fact 2012; 11:36. [PMID: 22448915 PMCID: PMC3364882 DOI: 10.1186/1475-2859-11-36] [Citation(s) in RCA: 203] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Accepted: 03/26/2012] [Indexed: 11/26/2022] Open
Abstract
Saccharomyces cerevisiae CEN.PK 113-7D is widely used for metabolic engineering and systems biology research in industry and academia. We sequenced, assembled, annotated and analyzed its genome. Single-nucleotide variations (SNV), insertions/deletions (indels) and differences in genome organization compared to the reference strain S. cerevisiae S288C were analyzed. In addition to a few large deletions and duplications, nearly 3000 indels were identified in the CEN.PK113-7D genome relative to S288C. These differences were overrepresented in genes whose functions are related to transcriptional regulation and chromatin remodelling. Some of these variations were caused by unstable tandem repeats, suggesting an innate evolvability of the corresponding genes. Besides a previously characterized mutation in adenylate cyclase, the CEN.PK113-7D genome sequence revealed a significant enrichment of non-synonymous mutations in genes encoding for components of the cAMP signalling pathway. Some phenotypic characteristics of the CEN.PK113-7D strains were explained by the presence of additional specific metabolic genes relative to S288C. In particular, the presence of the BIO1 and BIO6 genes correlated with a biotin prototrophy of CEN.PK113-7D. Furthermore, the copy number, chromosomal location and sequences of the MAL loci were resolved. The assembled sequence reveals that CEN.PK113-7D has a mosaic genome that combines characteristics of laboratory strains and wild-industrial strains.
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Affiliation(s)
- Jurgen F Nijkamp
- The Delft Bioinformatics Lab, Department of Intelligent Systems, Delft University of Technology, Mekelweg 4, 2628 CD Delft, The Netherlands
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García-Llobodanin L, Senn T, Ferrando M, Güell C, López F. Influence of the fermentation pH on the final quality of Blanquilla pear spirits. Int J Food Sci Technol 2010. [DOI: 10.1111/j.1365-2621.2010.02206.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Harsch MJ, Lee SA, Goddard MR, Gardner RC. Optimized fermentation of grape juice by laboratory strains of Saccharomyces cerevisiae. FEMS Yeast Res 2009; 10:72-82. [PMID: 19840118 DOI: 10.1111/j.1567-1364.2009.00580.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Laboratory strains of yeast (Saccharomyces cerevisiae) based on S288C ferment grape juice relatively poorly. We show that slow fermentation appears to be inherent to this strain, because the original S288C isolate shows fermentation similar to current laboratory isolates. We demonstrate further that some auxotrophic mutations in the laboratory strain show reduced rates of fermentation in grape juice, with lysine auxotrophs particularly impaired compared with isogenic Lys(+) strains. Supplementing lysine at a 10-fold higher concentration than recommended allowed yeast cultures to reach higher final cell densities and restored the fermentation rate of auxotrophic strains to those of the corresponding wild-type strains. However, even with the additional supplementation, the fermentation rates of S288C strains were still slower than those of a commercial wine yeast strain. Conditions were developed that enable auxotrophic laboratory strains derived from S288C to ferment grape juice to completion with high efficiency on a laboratory scale. Fermentation in media based on grape juice will allow the suite of molecular genetic tools developed for these laboratory strains to be used in investigations of complex ferment characteristics and products.
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Affiliation(s)
- Michael J Harsch
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
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Schehl B, Senn T, Lachenmeier DW, Rodicio R, Heinisch JJ. Contribution of the fermenting yeast strain to ethyl carbamate generation in stone fruit spirits. Appl Microbiol Biotechnol 2007; 74:843-50. [PMID: 17216464 DOI: 10.1007/s00253-006-0736-4] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2006] [Revised: 10/11/2006] [Accepted: 10/25/2006] [Indexed: 11/26/2022]
Abstract
Fermented fruit and beverages frequently contain ethyl carbamate (EC), a potentially carcinogenic compound that can be formed by the reaction of urea with ethanol. Both are produced by the yeast Saccharomyces cerevisiae with ethanol as the major end product of hexose fermentation and urea as a by-product in arginine catabolism. In spirit production, EC can also be derived from cyanide introduced by stone fruit. To determine the relative contribution of yeast metabolism to EC production, we genetically engineered a diploid laboratory strain to reduce the arginase activity, thus blocking the pathway to urea production. For this purpose, strains with either a heterozygous CAR1/car1 deletion or a homozygous defect (car1/car1) were constructed. These strains were compared to the parental wild type and to an industrial yeast strain in cherry mash fermentations and spirit production. The strain with the homozygous car1 deletion showed a significant reduction of EC in the final spirits in comparison to the non-engineered controls. Nevertheless, using this strain for fermentation of stoneless cherry mashes did not completely impede EC formation. This indicates another, as yet unidentified, source for this compound.
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Affiliation(s)
- Beatus Schehl
- Institut für Lebensmitteltechnologie, Fachgebiet Gärungstechnologie, Universität Hohenheim, Garbenstr 25, Stuttgart, Germany
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Guilloux-Benatier M, Remize F, Gal L, Guzzo J, Alexandre H. Effects of yeast proteolytic activity on Oenococcus oeni and malolactic fermentation. FEMS Microbiol Lett 2006; 263:183-8. [PMID: 16978354 DOI: 10.1111/j.1574-6968.2006.00417.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Alcoholic fermentation of synthetic must was performed using either Saccharomyces cerevisiae or a mutant Deltapep4, which is deleted for the proteinase A gene. Fermentation with the mutant Deltapep4 resulted in 61% lower levels of free amino acids, and in 62% lower peptide concentrations at the end of alcoholic fermentation than in the control. Qualitative differences in amino acid composition were observed. Changes observed in amino acids in peptides were mainly quantitative. After alcoholic fermentation, each medium was inoculated with Oenococcus oeni. Malolactic fermentation in the medium with the Deltapep4 strain took 10 days longer than the control. This difference may have been due to a difference in the nitrogen composition of the two media. Free amino acids and amino acids in peptides were poorly consumed by O. oeni. Thus, the qualitative aspects of nitrogen composition, which depend in part on yeast metabolism, may be a determinant for the optimal growth of O. oeni in wine.
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Affiliation(s)
- Michèle Guilloux-Benatier
- Laboratoire de Microbiologie, Institut Universitaire de la Vigne et du Vin Jules Guyot, Université de Bourgogne, Dijon Cedex, France
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Schehl B, Lachenmeier D, Senn T, Heinisch JJ. Effect of the stone content on the quality of plum and cherry spirits produced from mash fermentations with commercial and laboratory yeast strains. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2005; 53:8230-8. [PMID: 16218669 DOI: 10.1021/jf0511392] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
To evaluate the influence of stone content on spirit quality from stone fruit, cherry and plum mashes were prepared and fermented with a commercial and a diploid laboratory yeast strain. Fermentation parameters such as sugar content and ethanol production were followed. Despite an initial lag phase in cherry spirits, both yeast strains performed similarly, as substantiated by the determination of specific flavor compounds, ethyl carbamate, and methanol in the mashes and after distillation. The spirits produced were subjected to sensory analyses by trained panels of at least 25 judges. Although mashes retaining the stones could be clearly distinguished from those where the stones had been removed, no significant preference could be attributed to either spirit, indicating that qualities added by the presence of stones during fermentation are largely a matter of personal taste. Interestingly, the yeast strain used for fermentation seemed to have little influence on the spirit quality.
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Affiliation(s)
- Beatus Schehl
- Institut für Lebensmitteltechnologie, Universität Hohenheim, Fachgebiet Gärungstechnologie (150f), Garbenstrasse 25, D-70593 Stuttgart, Germany
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Lachenmeier DW, Schehl B, Kuballa T, Frank W, Senn T. Retrospective trends and current status of ethyl carbamate in German stone-fruit spirits. ACTA ACUST UNITED AC 2005; 22:397-405. [PMID: 16019810 DOI: 10.1080/02652030500073360] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Ethyl carbamate (urethane, C(2)H(5)OCONH(2)) is a known genotoxic carcinogen of widespread occurrence in fermented food and beverages with highest concentrations found in stone-fruit spirits. Between 1986 and 2004, 631 cherry, plum or mirabelle (yellow plum) spirits were analysed for ethyl carbamate using gas chromatography in combination with mass spectrometry after extrelut extraction. The ethyl carbamate concentration of the samples ranged between 0.01 mg l(-1) and 18 mg l(-1) (mean 1.4 mg l(-1)). After exposure of the samples to UV light, significantly (p=0.001) higher concentrations between 0.01 mg l(-1) and 26 mg l(-1) (mean 2.3 mg l(-1)) were found. The ethyl carbamate concentration increased on average by 1.3 mg l(-1). A linear correlation between the year of sampling and ethyl carbamate concentration showed a statistically significant but very slight decrease (R=-0.10, p=0.024). However, if only samples which officially were non-compliant were considered exceeding the upper limit of 0.4 mg l(-1) more than twice, a significant reduction (R =-0.56, p=0.018) of the quota was evident. This shows that measures to reduce ethyl carbamate were successfully introduced in many distilleries. However, nearly 20 years after the first warnings about ethyl carbamate in spirit drinks, the problem persists especially in products derived from small distilleries. During experimental production of stone-fruit spirits using state-of-the-art technologies, it was shown that the occurrence of ethyl carbamate in stone fruit spirits is preventable. Even for small distilleries, simple possibilities like destoning exist to minimize the ethyl carbamate content.
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Affiliation(s)
- Dirk W Lachenmeier
- Chemisches und Veterinäruntersuchungsamt Karlsruhe, Weissenburger Str. 3, D-76187 Karlsruhe, Germany.
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Current awareness on yeast. Yeast 2005; 22:241-8. [PMID: 15762016 DOI: 10.1002/yea.1159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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