IVAS 2022 banner
IVES 9 IVES Conference Series 9 IVAS 9 IVAS 2022 9 Analysis of mousy off-flavour wines

Analysis of mousy off-flavour wines

Abstract

Winemakers are increasingly experimenting with new techniques, such as spontaneous fermentation, prolonged yeast contact, higher pH, minimal sulphur dioxid, filtration and clarification or oxidative ageing. Along with this, the risk of microbial spoilage increases, and so the off-flavour mousiness, long time underestimated, is becoming more frequent. Characteristic of the mousy off-flavour is the delayed perception after swallowing the wine. After a few seconds the flavour appears, reminiscent of a dirty mouse cage. There are three known compounds that cause mousy off-flavor: 2-ethyltetrahydropyridine, 2-acetyltetrahydopyridine, and 2-acetylpyrroline. Yeasts such as Dekkera/Brettanomyces and heterofermentative lactic acid bacteria like Lactobacillus hilgardii can release these compounds.

This study focuses on the analysis of mousy wines. This includes the quantitative analysis of mousy off-flavour compounds in wine using liquid chromatography with mass spectrometry (HPLC-MS). In order to identify the microorganisms in mousy wines, a next-generation sequencing analysis was carried out. Based on these results, a qPCR method will be developed to quantify the corresponding microorganisms in wine. 

DOI:

Publication date: June 27, 2022

Issue: IVAS 2022

Type: Poster

Authors

Dietzel Caroline1, Wegmann-Herr Pascal1 and Scharfenberger-Schmeer Maren2

1Institute for Viticulture and Enology (DLR-Rheinpfalz)
2University of Applied Sciences, Kaiserslautern

Contact the author

Keywords

Mousy off-flavour, Wine fault, qPCR, Next-Generation-Sequenzing, LC-MS

Tags

IVAS 2022 | IVES Conference Series

Citation

Related articles…

Application to the wine sector of European Convention on the landscapes

The landscape is defined by the European convention of the landscape (Florence, October 20, 2000) like part of the territory as perceived by the populations, whose character results from the action of natural and/or human factors and their interrelationships. This convention is based on the contribution cultural, ecological, environmental, social of the landscapes and aims at a reinforcement of the tools of protection and valorization in particular in the agricultural policies, of regional planning and town planning. Moreover, it encourages a step of identification and qualification of the landscapes and underlines the need for developing the sensitizing and the training of the actors concerned.

Key odorants responsible for the sensory spaces defining the different aroma potentials of Grenache and Tempranillo grapes

There are yet many gaps in our knowledge about the aroma potential of winemaking grapes and its measurement. Trying to bring some light into this question, a new general strategy based on the accelerated hydrolysis of reconstituted phenolic and aromatic fractions (PAFs) extracted from grapes has been developed

How small amounts of oxygen introduced during bottling and storage can influence the metabolic fingerprint and SO2 content of white wines

The impact of minute amounts of headspace oxygen on the post-bottling development of wine is generally considered to be very important, since oxygen, packaging and storage conditions can either damage or improve wine quality. This is reflected in the generalised use of inert bottling lines, where the headspace between the white wine and the stopper is filled with an inert gas. This experiment aimed to address some open questions about the chemistry of the interaction between wine and oxygen, crucial for decisions regarding optimal closure. While it is known that similar amounts of oxygen affect different wines to a variable extent, our knowledge of chemistry is not sufficient to construct a predictive method.

Grapevine adaptation to drought and resistance to Neofusicoccum parvum, causal agent of Botryosphaeria dieback

The sustainability of viticulture in response to climate change has been addressed mainly considering agronomic impacts, such as water management and diseases, either separately or together.
In grapevines, there is strong evidence that different genotypes respond differently to biotic and abiotic stresses. A screening was conducted on various local cultivars in response to drought and Neofusicoum parvum infection aiming to evaluate their susceptibility to abiotic stress and resistance to fungal diseases.

Use of artificial intelligence for the prediction of microbial diseases of grapevine and optimisation of fungicide application

Plasmopara viticola, the causal agent of downy mildew (DM), and Uncinula necator, the causal agent of powdery mildew (PM), are two of the main phytopathogenic microorganisms causing major economic losses in the primary sector, especially in the wine sector, by wilting bunches and leaves with a consequent decrease in the photosynthetic rate of the plant and in the annual yield. Currently, the most widespread methods for planning spraying are based on the 3-10 rule, which states that the first application should take place when: (i) the air temperature is greater than 10°C; (ii) shoots are equal or greater than 10 cm; and (iii) a minimum of 10 mm rainfall within 24–48 hours has occurred, or at the beginning of the bud break with periodic applications according to the manufacturer’s instructions.