Macrowine 2021
IVES 9 IVES Conference Series 9 Efficiency of alternative chemical and physical treatments in reducing Brettanomyces Bruxellensis from oak wood

Efficiency of alternative chemical and physical treatments in reducing Brettanomyces Bruxellensis from oak wood

Abstract

Oak barrels form an integral part of wine production, especially that of high quality wines. However, due to its porosity, wood presents an ecological niche for microbial proliferation and is highly susceptible to microbial spoilage which could cause considerable economic losses. Brettanomyces bruxellensis, the most commonly encountered microorganism responsible for spoilage during barrel ageing, can remain in barrels after barrel sanitation to contaminate new batches of wine after refilling. Therefore, effective sanitation treatments are of utmost importance to prevent recurring wine spoilage. Since a moratorium on the use of sulphur dioxide, the most widely used biocide for barrel sanitation, has been issued by the European Commission, there is a drastic need to evaluate alternative sanitation methods. Literature on the effectiveness of barrel sanitation treatments is scattered and presents inconclusive results. Furthermore, all studies have used culture-dependent methods to detect Brettanomyces which has been reported to attain a viable but non-culturable state [1,2]. Therefore, the aim of this study was to evaluate several physical and chemical sanitation treatments in their efficiency to eliminate B. bruxellensis from oak wood. French oak wood was contaminated with different B. bruxellensis strains and subsequently subjected to several chemical and physical sanitation treatments. The methods included, among others, ozone gas, ozonated water, high pressure ultrasound, steam, peracetic acid, sodium percarbonate and microwave. After their extraction from the oak wood, Brettanomyces cells were subjected to a fluorescence-based live/dead staining and detected by means of flow cytometry. The treatments differed greatly in their ability to reduce B. bruxellensis cells with ozone gas showing promising results. Sodium percarbonate and steam treatments were also effective in reducing cells. This study presents the first evaluation of alternative barrel sanitation treatments by flow cytometry, a culture-independent method, and is also the first study to compare an array of barrel sanitation treatments under controlled conditions.

1. Agnolucci, M., Rea, F., Sbrana, C., Cristani, C., Fracassetti, D., Tirelli, A., Nuti, M., 2010. Sulphur dioxide affects culturability and volatile phenol production by Brettanomyces/ Dekkera bruxellensis. International Journal of Food Microbiology 143, 76-80. 2. Serpaggi, V., Remize, F., Recorbet, G., Gaudot-Dumas, E., Sequeira-Le Grand, A., Alexandre, H., 2012. Characterization of the “viable but nonculturable”(VBNC) state in the wine spoilage yeast Brettanomyces. Food Microbiology 30, 438-447.

Publication date: May 17, 2024

Issue: Macrowine 2016

Type: Article

Authors

Engela Kritzinger*, Maren Scharfenberger-Schm, Ulrich Fischer

*DLR Rheinpfalz

Contact the author

Tags

IVES Conference Series | Macrowine | Macrowine 2016

Citation

Related articles…

IBMP-Polypenol interactions: Impact on volatility and sensory perception in model wine solution

3-Isobutyl-2-methoxypyrazine (IBMP) is one of the key molecules in wine aroma with a bell pepper aroma and a very low threshold in wine, 1-6 ng/L for white wine and 10-16 ng/L in red wine1. The differences in these thresholds are likely due to IBMP-non volatile matrix interactions. It has indeed been shown that polyphenols may influence the volatility of flavor compounds2. In the present study, we focus on IBMP-polyphenols interactions in relation to volatility and sensory perception in model wine solution. Methods: 1. GC-MS Static Headspace Analysis: Samples were analyzed by Static headspace analysis with an Agilent 7890A gas chromatograph coupled to HP 5975C mass spectrometry detector (Agilent Technologies, Santa Clara, CA, USA).

How pressing techniques affect must composition and wine quality of Pinot blanc

This study investigates how the sensory profile of Pinot Blanc is affected from different maceration and pressing techniques. Grapes were sourced from four vineyards in the village Tramin in South Tyrol. For the experiment 200 kg of grapes from each vineyard site were hand picked the day before harvest for the commercial winery took place. Grapes were stored over night at 4°C, homogenized and processed in the experimental winery at Laimburg research centre the day after harvest. Four different pressing techniques were applied in duplicates of 100kg each.

Monitoring of Pesticide Residues from Vine to Wine

Those previous years, pesticides are often brought to the forefront by media. Questions arose about their toxicity for growers and consumers. Even if a downward trend is underway, the use of pesticides is required to ensure steady quality and quantity of harvests. A large number of active ingredients are authorized but regarding viticulture, mainly insecticides and fungicides are applied, to control pests and diseases and to increase crop yield. Some phytosanitary products, principally fungicides, applied close to the harvest date may frequently be detected in wines.

The effect of Nitrogen and Sulphur foliar applications in hot climates

ine nitrogen deficiency can negatively influence the aroma profile and ageing potential of white wines. Canopy management can alter vine microclimate, affect the nitrogen availability and influence the response of leaf senescence. Increasing the nitrogen availability to vines can increase the Yeast Assimilable Nitrogen (YAN) levels in harvested fruit and wine. Studies show that foliar nitrogen and sulphur applications at véraison, on low YAN Sauvignon blanc grapes have an effect on the level of amino acids (Jreij et al. 2009) and on S-containing compounds such as glutathione and thiols (Lacroux et al. 2008), which in turn can influence the formation of major volatiles and the aroma profile of the wine.

Quantification of red wine phenolics using ultraviolet-visible, near and mid-infrared spectroscopy combined with chemometrics

The use of multivariate statistics to correlate chemical data to spectral information seems as a valid alternative for the quantification of red wine phenolics. The advantages of these techniques include simplicity and cost effectiveness together with the limited time of analysis required. Although many
publications on this subject are nowadays available in the literature most of them only reported feasibility
studies. In this study 400 samples from thirteen fermentations including five different cultivars plus 150
wine samples from a varying number of vintages were submitted to spectrophotometric and chromatographic phenolic analysis.