terclim by ICS banner
IVES 9 IVES Conference Series 9 INVESTIGATION INTO MOUSY OFF-FLAVOR IN WINE USING GAS CHROMATOGRAPHY-MASS SPECTROMETRY WITH STIR BAR SORPTIVE EXTRACTION

INVESTIGATION INTO MOUSY OFF-FLAVOR IN WINE USING GAS CHROMATOGRAPHY-MASS SPECTROMETRY WITH STIR BAR SORPTIVE EXTRACTION

Abstract

Mousy off-flavor is one of the defects of microbial origin in wine. It is described as a particularly unpleasant defect reminiscent of rodent urine (a “dirty mouse cage”), and grilled foods such as popcorn, rice, crackers, and bread crust. Prior to the 2010s, mousiness was very uncommon but it has been becoming more frequent in recent years. It is often associated with an increase in pH as well as certain oenological practices, which tend to significantly decrease the use of sulfur dioxide.

Three major compounds, 2-acetyl-1-pyrroline (APY), 2-acetyltetrahydropyridine (ATHP) and 2-ethyltetrahydropyridine (ETHP), have been identified as responsible for mousiness in wines. A particularity of these compounds is that they are prone to tautomerism and can coexist in several forms. Moreover, the nitrogen atom in the heterocyclic ring can be protonated under specific conditions, i.e. with pH lower than pKa, inducing a positive charge and, as a consequence, an increase of polarity and a loss of volatility of the molecule.

To date quantification data reported in the literature are limited due to analytical issues related to the nature of these compounds. To fill the gap and later understand the parameters influencing mousiness, the objective of this study was to develop a simple and effective method to simultaneously determine trace levels of these three mousy N-heterocycles in wines. Therefore, a stir bar sorptive extraction (SBSE) followed by GC-MS analysis was developed (1).

Firstly, both previously reported tautomers of ATHP (2), 2-acetyl-1,4,5,6-tetrahydropyridine and 2-acetyl-3,4,5,6-tetrahydropyridine were identified, unlike to APY and ETHP. The extraction conditions were then optimized paying particular attention to the pH of the sample. The performance of the developed method was evaluated on white, rosé and red wines and the limits of detection and quantification of the method are lower than previously published concentrations in spoiled wine.

The method was then applied to provide quantitative data by analyzing 6 control wines and 68 wines produced without added sulfites. ETHP was detected in almost all wines produced with limited use of SO₂. ATHP was detected in almost all wines suspected of mousiness whereas APY was only detected in few cases. This method will provide a support for further studies aimed at understanding the phenomena that influence the occurrence of mousy off-flavor and the oenological parameters that modulate its expression.

DOI:

Publication date: February 9, 2024

Issue: OENO Macrowine 2023

Type: Poster

Authors

Céline Franc¹, Daiki Kiyomichi², Pierre Moulis1,3, Laurent Riquier¹, Patricia Ballestra¹, Stéphanie Marchand¹, Sophie Tempère1 and Gilles de Revel¹

1. Univ. Bordeaux, INRAE, Bordeaux INP, Bordeaux Sciences Agro, UMR 1366, OENO, ISVV, F-33140 Villenave d’Ornon, France
2. Institute for Future Beverages, Kirin Holdings Company, Limited, 4-9-1 Jonan, Fujisawa, Kanagawa 251-0057, Japan
3. Department of Microbiology and Biochemistry, Hochschule Geisenheim University, Geisenheim, Germany

Contact the author*

Keywords

mousiness, N-heterocycles, quantification, SBSE-GC-MS

Tags

IVES Conference Series | oeno macrowine 2023 | oeno-macrowine

Citation

Related articles…

WHICH IMPACT FOR PROANTHOCYANIDIC TANNINS ON RED WINE FRUITY AROMA? SENSORY AND PHYSICOCHEMICAL APPROACHES

Previous research on the fruity character of red wines highlighted the role of esters. Literature provides evidence that, besides these esters, other compounds that are not necessarily volatiles may have an important impact on the overall aroma of wine, contributing to a modulation of its global aromatic expression. The goal of this work was to assess the olfactory consequences of a mixture between esters and proanthocyanidic tannins, through sensory and physico-chemical approaches.
Sensory analysis of numerous aromatic reconstitutions, including triangular tests, detection thresholds, and sensory profiles, were conducted in order to evaluate the sensory impact of tannins on red wine esters perception.

Read More

EMERGENCE OF INORGANIC PHOSPHONATE RESIDUES IN GRAPEVINE PLANT PARTS, BERRIES AND WINES FROM SOURCES OTHER THAN FOLIAR SPRAYING

Inorganic phosphonates are known to effectively support the control of grapevine downy mildew in vi- ticulture. Their application helps the plant to induce an earlier and more effective pathogen defense. However, inorganic phosphonates have been banned in organic viticulture due to their classification as plant protection products since October 2013. Despite the ban, phosphonate has been recently detected in organic wines.

Read More

VOLATILE COMPOSITION OF WINES USING A GC/TOFMS: HS-SPME VS MICRO LLE AS SAMPLE PREPARATION METHODOLOGY

Wine aroma analysis can be done by sensorial or instrumental analysis, the latter involving several me-thodologies based on olfactometric detection, electronic noses or gas chromatography. Gas Chromatography has been widely used for the study of the volatile composition of wines and depending on the detection system coupled to the chromatographic system, quantification and identification of individual compounds can be achieved.

Read More

WHAT’S FUTURE FOR SANTORINI’S VITICULTURE IN THE CONTEXT OF CLIMATE CHANGE

The own-rooted vineyard of Santorini is a unique case of vineyard worldwide that is been cultivated for thousands of years. On the island’s volcanic soil, the vines are still cultivated with traditional techniques, which are adapted to the specific and extreme weather conditions that prevail on it. While climate change is a reality in the Mediterranean region, will Santorini vineyard endure its impact? The study of the traditional training systems, techniques and vine density, as well as the application of sustainable solutions (cover crops and use of kaolin etc.) revealed sustainable methods for the adaptation of the local viticulture to new climatic phenomena that tend to be more and more frequent in the region due to climate change.

Read More

NEUROPROTECTIVE AND ANTI-INFLAMMATORY PROPERTIES OF HYDROXYTYROSOL: A PROMISING BIOACTIVE COMPONENT OF WINE

Hydroxytyrosol (HT) is a phenolic compound present in olives, virgin olive oil and wine. HT has attracted great scientific interest due to its biological activities which have been related with the ortho-dihydroxy conformation in the aromatic ring. In white and red wines, HT has been detected at concentrations ranging from 0.28 to 9.6 mg/L and its occurrence has been closely related with yeast metabolism of aromatic amino acids by Ehrlich pathway during alcoholic fermentation. One of the most promising properties of this compound is the neuroprotective activity against pathological mechanisms related with neurode-generative disorders including Alzheimer’s and Parkinson’s disease.

Read More