High pressure inactivation of Brettanomyces bruxellensis in red wine

Brettanomyces is a major threat to red wine quality, causing off-odors such as “medicinal,” “barnyard,” or even “sewage” during aging. Although sulfites (SO2) are used to limit spoilage by these yeast cells, reduced storage temperatures may lessen SO2 requirements. To test this hypothesis, a 4 × 4 factorial experimental design with molecular SO2 (mSO2) concentration (0.0, 0.2, 0.5, or 1.1 mg/liter) and storage temperature (22, 18, 15, or 10°C) was devised. Of three strains evaluated, B5 was the lone strain to regain culturability following exposure to 0.5 mg/liter mSO2 (18°C), whereas only F3 remained culturable in the absence of mSO2 at 10°C. Application of fluorescence microscopy using two different probes and quantitative PCR assays revealed only a 2-log reduction in metabolically active cells from wines with SO2 that were not culturable on nonselective media. Culturability in these wines eventually returned regardless of the concentration of mSO2 present. In addition, 4-ethylphenol production ceased upon addition of SO2. These findings provide additional support that Brettanomyces can enter a “viable-but-not-culturable” state upon exposure to sulfites. Given the diversity among strains, maintaining conditions of ≤15°C and ≥0.4 mg/liter mSO2 will help limit spoilage by Brettanomyces but will not lead to its complete eradication.

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Advanced ultra high pressure liquid chromatography–tandem mass spectrometric methods for the screening of red wine anthocyanins and derived pigments

Journal of Chromatography A ◽

10.1016/j.chroma.2012.02.058 ◽

2012 ◽

Vol 1235 ◽

pp. 92-102 ◽

Cited By ~ 33

Author(s):

Philippus Alberts ◽

Maria A. Stander ◽

André de Villiers

Keyword(s):

High Pressure ◽

Liquid Chromatography ◽

High Pressure Liquid Chromatography ◽

Red Wine ◽

Mass Spectrometric ◽

Tandem Mass ◽

Ultra High Pressure ◽

Liquid Chromatography Tandem Mass ◽

Tandem Mass Spectrometric

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Evaluation of three Brettanomyces qPCR commercial kits: results from an interlaboratory study

OENO One ◽

10.20870/oeno-one.2016.50.4.1274 ◽

2016 ◽

Vol 50 (4) ◽

Cited By ~ 2

Author(s):

Cédric Longin ◽

Frédérique Julliat ◽

Virginie Serpaggi ◽

Julie Maupeu ◽

Geoffrey Bourbon ◽

...

Keyword(s):

Internal Control ◽

Red Wine ◽

Classical Method ◽

False Negative ◽

Selective Medium ◽

Interlaboratory Study ◽

Brettanomyces Bruxellensis ◽

Spoilage Yeast ◽

Commercial Kits ◽

Detection And Quantification

Brettanomyces bruxellensis is well adapted to high ethanol concentrations and low pH which allows it to develop in difficult environments, such as wine. B. bruxellensis is mainly found in red wine and is regarded as a spoilage yeast due to its production of ethylphenols and other compounds responsible for organoleptic defects. The detection and quantification of this yeast is essential to preventing wine spoilage. Several specific detection and quantification kits based on real time quantitative PCR are commercially available. Although these kits are frequently used by private enological and research laboratories, no scientific report on the reliability and performance of these kits, including inter-laboratory and inter-assay comparisons have been published. The aim of this work was to compare available kits to quantify B. bruxellensis in red wine to classical method (plate counting on selective medium) in an interlaboratory study. Three different commercial kits were tested on three different wines from Bordeaux, Côtes du Rhône, and Burgundy inoculated with B. bruxellensis at four different concentrations. Five naturally contaminated wines from different French wine regions were also tested. Our results suggest that all the kits tested probably over or underestimate the quantity of B. bruxellensis in red wine and, under specific conditions, give false positives. Quantification may be very heterogeneous depending on the wine, laboratory, or population level. Underestimations or false negative results may have serious consequences for winemakers. Overestimation may be partly due to the quantification of dead cells qPCR.This study highlights that quantification of B. bruxellensis in red wine using commercial kits requires a high level of expertise in molecular biology. We recommend that all users use a microbiological internal control to validate DNA extraction yield.

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Inactivation of Brettanomyces bruxellensis and Saccharomyces cerevisiae in dry and sweet wines by high hydrostatic pressure

OENO One ◽

10.20870/oeno-one.2020.54.4.3540 ◽

2020 ◽

Vol 54 (4) ◽

pp. 657-670

Author(s):

Marina Tomašević ◽

Stela Križanović ◽

Damir Ježek ◽

Natka Ćurko ◽

Katarina Lukić ◽

...

Keyword(s):

Saccharomyces Cerevisiae ◽

Hydrostatic Pressure ◽

High Hydrostatic Pressure ◽

Red Wine ◽

Phenolic Content ◽

White Wine ◽

Colour Difference ◽

Invasive Treatment ◽

Brettanomyces Bruxellensis ◽

Sweet Wines

The aim of the research was to investigate a potential application of high hydrostatic pressure (HHP) for reduction/elimination of Brettanomyces bruxellensis and Saccharomyces cerevisiae in wines. Dry red wine was inoculated with B. bruxellensis and sweet white wine was inoculated with S. cerevisiae yeast. Both wines were treated by HHP under 100 and 200 MPa for 1, 3, 5, 15 and 25 min. The culturability was determined immediately after the treatment and again after 30, 60 and 90 days of storage. The phenolic content and chromatic characteristics were evaluated spectrophotometrically immediately after the treatment and after 90 days of storage. The culturability of B. bruxellensis was not confirmed immediately after the most invasive treatment (200 MPa for 15 and 25 min). With the same parameters, only a decrease in the culturability of S. cerevisiae was observed. During storage, opposing results were observed for two yeasts treated with 200 MPa for 15 and 25 min: there was a complete reduction of S. cerevisiae in the wine treated, but the culturability of B. bruxellensis completely recovered in all wines, implying that B. bruxellensis yeast entered a viable but not culturable (VBNC) state after HHP exposure. Regarding the chemical analyses, applied process parameters induced a slight decrease of anthocyanins in red wine, while changes of total phenolics and total colour difference value were negligible. In conclusion, HHP could potentially be successful for microbial stabilisation of sweet wines and consequently assure a lower use of sulphur dioxide, while inactivation of B. bruxellensis could only be successful in the early stages of wine contamination.

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Reducing SO2 content in wine by combining High Pressure and glutathione addition

OENO One ◽

10.20870/oeno-one.2021.55.1.4558 ◽

2021 ◽

Vol 55 (1) ◽

pp. 235-252

Author(s):

Stefania Christofi ◽

George Katsaros ◽

Athanasios Mallouchos ◽

Valeriu Cotea ◽

Stamatina Kallithraka

Keyword(s):

High Pressure ◽

Acetic Acid ◽

Sensory Analysis ◽

Red Wine ◽

Quality Parameters ◽

Volatile Acidity ◽

Long Duration ◽

Pressure Time ◽

Antimicrobial Protection ◽

Total Anthocyanins

The aim of this work was to examine the potential of High Pressure (HP) technology as an alternative technique to SO2 addition for red wine preservation. It focused on producing wines with reduced added SO2 and the simultaneous addition of glutathione (GSH) as a natural antioxidant. Selected quality parameters of red wine samples from Mouchtaro grapes treated by HP using various pressure parameters were tested. HP processing studied was applied at 200, 400 and 600 MPa for 0, 5 and 15 min. The application of HP for a long duration resulted in a significant reduction in phenolic compound concentrations (TP) due to both extended polymerisation and reduced volatile acidity (VA) and acetic acid concentrations (AAC), which in turn was mainly due to better antimicrobial protection. Based on the changes to the contents of all TP, VA and AAC groups, processing for 5 min at 400 MPa was selected as the optimum HP condition. Red wine samples from Mouchtaro grapes containing 0, 20, 40, 60, 80 and 100 mg/L of SO2 and 10 mg/L of GSH were HP-treated under the selected pressure/time conditions. Untreated samples containing the same concentrations of SO2 and GSH were used as control samples. Indices such as AAC, Antioxidant activity (AOA), total anthocyanins, TP, mean Degree of Tannin Polymerisation (mDP) and the composition of volatiles was determined over a period of 12 months. Sensory analysis of the samples took place during the 12th month of storage. After the 12-month period, the pressurised samples with GSH showed higher content of total aldehyde/ketone and higher-alcohols, consistently lower concentrations of acetic acid, ethyl acetate and total esters, and lower VA values. Finally, based on the results obtained from the sensory analysis, untreated samples were characterised by "Red fruits" odours, whereas treated samples were distinguished by their "chocolate" aroma. These results suggest that HP could be used for the production of more "mature" wines. A reduced SO2 concentration of up to 40 or 60 mg/L may be sufficient for wine stabilisation when combining HP treatment and GSH additions, depending on grape variety.

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