METHOD FOR PREVENTING MOUSE TASTE IN FERMENTED BEVERAGES

Abstract

The present invention relates to the use of yeast hulls to treat the development of the off-flavor known as "mousey taste" in fermented beverages such as wine. The invention also relates to a process for preparing a fermented beverage comprising a step in which a fermented and / or fermentable beverage is brought into contact with yeast hulls. Treatment with yeast hulls reduces the concentration of molecules known to be responsible for the development of mouey taste in wine.

Description

Title of the invention: METHOD FOR PREVENTING MOUSE TASTE IN FERMENTED BEVERAGES technical field

[0001] This disclosure relates to processes for preparing fermented beverages such as wine. The present invention is particularly aimed at preventing and / or reducing the defect known as "mousey taste" in fermented beverages. Prior art

[0002] “Mousey taste” or “GDS” is a microbial alteration that taints the taste of many fermented beverages such as wine (Snowdon, Eleanor M., et al. “Mousy off-flavor: a review.” Journal of agricultural and food chemistry 54.18 (2006): 6465-647) or beer (Martusevice, Paulina, et al. “A Review of N-Heterocycles: Mousy Off-Flavor in Sour Beer.” Journal of Agricultural and Food Chemistry 72.14 (2024): 7618-7628).

[0003] It manifests itself as a particularly unpleasant defect which, upon tasting, is reminiscent of either the odor emanating from rodent cages or the odor of grilled or puffed foods such as popcorn, rice, crackers, or bread crust. Some tasters even mention a taste reminiscent of sausage skin, vomit, or a dirty mop.

[0004] This mousey taste is perceived through retronasal olfaction, when the beverage mixes with saliva, and can persist in the mouth for several minutes, whether the beverage is swallowed or spat out. Its appearance impairs the organoleptic qualities of the beverage and can lead to the total loss of the products concerned, which translates into disastrous economic consequences for the producer.

[0005] Three molecules have been identified as being responsible for the appearance of the mousey taste in wine: 2 acetyltetrahydropyridine (ATHP), 2 ethyltetrahydropyridine (ETHP) and 2 acetyl 1 pyroline (APY), with ATHP having been shown to be the most present molecule in the case of mousey taste.

[0006] These molecules are synthesized from two amino acids, lysine and omithine, by indigenous microorganisms present in the beverage. Initial studies of the flora observed in wines exhibiting the GDS defect demonstrated that two microorganisms, Brettanomyces yeasts and lactic acid bacteria of the genera Lactobacillus and Oenococcus, are responsible for the detrimental expression of these three molecules. Each of these microorganisms can contaminate the wine independently of the others and produce one or more of these molecules.

[0007] Conditions that favor microbial growth therefore also increase the risk of developing the mousey taste defect. However, since the early 2000s, strong consumer demand for more "natural" products has led to a significant decrease in the use of sulfites, which play an antioxidant and antiseptic role. At the same time, changes in harvesting conditions have also resulted in a steady increase in the pH of wines (to pH levels above 3.5). These conditions, conducive to bacterial growth, have led to a sharp increase in the rate of wines contaminated by the mousey taste since the end of the last century.

[0008] Currently, no preventive or curative method exists to eliminate the mousey taste of a beverage. The only recommendations offered involve adding activated charcoal, ellagic tannins, sulfites, or chitosan in an attempt to reduce its perception. Unfortunately, these products do not satisfactorily eliminate the mousey taste and exhibit inconsistent performance over time.

[0009] There is therefore a real need for solutions to effectively prevent and / or treat the appearance of mousey taste in beverages affected by this defect, such as wine or beer. It is essential that these solutions comply with current standards and respect consumer preferences regarding the limitation of additive use. Summary

[0010] Quite surprisingly, the present inventors have demonstrated that treatment with yeast hulls chemically reduces the concentration of molecules responsible for the mousey taste. The present inventors have also demonstrated that this treatment eliminates the perception of the mousey taste in wines of various types affected by this defect. The treatment is simple, leaves no trace in the treated beverage, and can be easily carried out using commercially available yeast hulls.

[0011] Yeast hulls are already used in winemaking to compensate for sudden stops in fermentation. These stops are due to the presence of compounds toxic to yeast produced in the fermentation medium. The use of hulls allows the fermentation medium to be detoxified by adsorbing these toxic compounds. However, these compounds, such as decanoic and octanoic acids, are of a completely different nature from the compounds responsible for the mousey taste. Nothing suggested that yeast hulls could also neutralize molecules such as ATHP, ETHP, or APY, nor that they could effectively combat the mousey taste in a beverage. The inventors have demonstrated, for example, that the use of hulls of yeasts were ineffective in treating the "corked taste" defect, which was due to the presence of halophenols in the wine.

[0012] The effectiveness of a treatment with yeast hulls to prevent or reduce the mousey taste defect is therefore quite remarkable and provides a welcome solution to a problem affecting many producers.

[0013] Also, according to a first aspect, the present invention relates to the use of yeast hulls to prevent and / or reduce the mousey taste defect in a fermented beverage.

[0014] The present invention also relates to a method for preparing a fermented beverage, said method comprising a step in which a fermented and / or fermentable beverage is brought into contact with yeast hulls for a period of between 2 and 31 days, preferably between 7 and 24 days.

[0015] The process according to the invention may advantageously include a step in which the barks are removed after treatment, for example by filtration.

[0016] The fermented beverage according to the invention may advantageously be wine or beer.

[0017] The present invention also relates to the use of yeast hulls to reduce the concentration of 2-acetyltetrahydropyridine (ATHP) in a beverage. Brief description of the figures Fig. 1

[0018] [Fig.1]: Evaluation of the intensity of the mouse taste by sniffing on Chenin Blanc n°1 Vallée de la Loire 2021. Fig. 2

[0019] [Fig.2]: Evaluation of the intensity of the mouse taste by sniffing Chenin Blanc n°2 Vallée de la Loire 2021. Detailed description of the invention

[0020] The present invention relates to the use of yeast hulls to prevent and / or treat the occurrence of the mousey taste defect in a fermented beverage.

[0021] The invention also relates to a method for preparing a fermented beverage, said method comprising a step in which a fermented and / or fermentable beverage is brought into contact with yeast hulls for a period of between 2 and 31 days, preferably between 7 and 24 days.

[0022] The "mousy off-flavor" defect is well documented and well known to those skilled in the art (see, for example, Costello, PJ (1998) 'Formation of mousy off-flavor in wine by lactic acid bacteria' PhD thesis (University of Adelaide: Adelaide); Mousy off-flavor: a review." Journal of agricultural and food chemistry 54.18 (2006): 6465-647; Costello, PJ, Lee, TH, Henschke, PA (2001) Kbility of lactic acid bacteria to produce N-heterocycles causing mousy off-flavor in wine. Australian Journal of Grape and Wine Research, 7, 160-167; Grin, P.R., Costello, P.J., Herderich, M., Markides, A J., Henschke, P.A. and Lee, T.H. (1996) Developments in the sensory, Chemical and microbiological basis of mousy taint in wine. C.S. Stockley, A.N. Sas, RS Johnston and TH Lee (eds) Proceedings of the ninth Australian wine industry technical conference, Adelaide, Australia (Winetitles: Adelaide) pp. 57-61). It corresponds to an olfactory defect perceptible mainly in retronasal olfaction after putting a fermented beverage in the mouth. This defect can evoke various tastes, more or less unpleasant for the consumer, including rodent urine, from which it derives its name. It is now well established that this defect results primarily from the expression, in the beverage, of at least one of the three molecules 2-acetyltetrahydropyridine (ATHP), 2-ethyltetrahydropyridine (ETHP), and 2-acetyl-1-pyroline (APY) by microorganisms such as Brettanomyces yeasts and lactic acid bacteria of the genera Lactobacillus and Oenococcus. The use of yeast hulls helps to reduce the content of these molecules in the beverage.The inventors have particularly demonstrated that treatment with yeast hulls makes it possible to significantly reduce the concentration of ATHP, the molecule most frequently found in the presence of a mousey taste, in a fermented or fermentable beverage.

[0023] In this context, the invention also relates to the use of yeast hulls to reduce the ATHP content in a fermented and / or fermentable beverage.

[0024] The observed decrease in ATHP concentration is on the order of at least 10%, preferably at least 20%, and even more preferably at least 40%, compared to the concentration observed in an untreated control beverage. An untreated control beverage is understood to be a beverage identical in all respects except that it has not been brought into contact with the yeast hulls.

[0025] The "yeast hulls" used in the context of the present invention correspond to the husks obtained after yeast lysis. A yeast cell is schematically composed of a hull and cell contents. The hull is called the "cell wall" or "shell" and consists of the insoluble fraction obtained after yeast lysis. Yeast cell walls can be obtained in various ways, from different types of yeast, possibly in mixtures, using different techniques.Yeast cell walls can be obtained by various lysis methods, including autolysis, heterolysis, enzymatic lysis (via the addition of proteases), chemical lysis (generally involving the use of a lysis buffer, which may be combined with a detergent), or mechanical lysis (via the use of an agent that physically induces cell membrane rupture using shear force). The lysis (autolysis or heterolysis) of yeast cells is monitored. The process involves separating the soluble and insoluble fractions and then collecting the insoluble fraction. The insoluble fraction is generally collected by removing the soluble fraction through centrifugation. The insoluble fraction thus obtained corresponds to the yeast cell walls, referred to as "yeast hulls" in the context of the present invention. The cell walls represent approximately 25 to 45% of the dry weight of the whole yeast cell, with an average of about 35%. The soluble fraction (clear in color and with low turbidity) corresponds to the "yeast extract." The yeast hulls used in the context of the present invention can be readily obtained from specialized manufacturers. An example of a suitable product is the product marketed under the SpringCell™ brand by Fermentis (Lesaffre).

[0026] The yeast hulls used in the context of the present invention can be obtained from yeasts of several genera and / or species (and thus be a mixture of yeast hulls of different genera and / or species), or be obtained from yeasts of a single genus, or even a single species. According to a particular embodiment, the yeast hulls can be hulls derived from yeasts of the genus Saccharomyces, preferably from the species Saccharomyces cerevesiae.

[0027] By "preventing" the mousey taste defect, we mean preventing the development of this defect before it appears in the beverage. This means that the beverage does not have the mousey taste defect at the time of treatment with the yeast hulls, but that it would have had it after a time t in the absence of treatment.

[0028] By "reducing" the mousey taste defect, we mean here to decrease or even eliminate the perception of the mousey taste in a beverage exhibiting this defect. This reduction can, for example, be measured by establishing a scale for evaluating the intensity of the mousey taste. Such a method is presented in the experimental part of the present invention. The use of yeast hulls makes it possible to reduce the perception of the mousey taste by at least 20%, particularly by at least 40%, and even more particularly by at least 50%, compared to an untreated control beverage, after 13 to 24 days of treatment.

[0029] The “beverage” prepared and / or treated within the framework of the present invention can be any beverage, i.e. consumable, fermented or fermentable liquid.

[0030] The term "fermented beverage" herein means a beverage which, during its preparation, has undergone a fermentation step with a fermentative microorganism such as a fermentative bacterium or a yeast. During fermentation, the carbon sources, such as sugars, contained in the beverage are used by the fermentative microorganism to produce various compounds such as carbon dioxide. These compounds vary depending on the microorganism and the fermentation pathway involved.

[0031] Within the framework of the present invention, the fermented beverage can, for example, be chosen from wines, such as red wines, white wines, rosé wines and champagnes, fruit and / or vegetable-based beverages including ciders, kombucha or mead, cereal-based beverages such as beer, dairy-based beverages or vinegars.

[0032] Preferably, the fermented beverage according to the present invention is a wine or a beer. Even more preferably, the fermented beverage is a wine.

[0033] The term "fermentable beverage" here refers to a beverage that can undergo a fermentation step to obtain a fermented beverage. A fermentable beverage typically has not yet undergone a fermentation step, or has not undergone a sufficient fermentation step to reach the final fermented beverage and allow for its consumption.

[0034] In the context of the present invention, the beverage is brought into contact with the yeast hulls for a period of 2 to 31 days, preferably between 7 and 24 days.

[0035] In order to prevent or reduce the perception of mouse taste, yeast hulls are typically used at a concentration of 10 to 100 g / hL of beverage, preferably 20 to 60 g / hL of beverage, even more preferably 30 to 40 g / hL of beverage.

[0036] After treatment, the yeast hulls are typically removed so that the fermented beverage to be consumed no longer contains them. A person skilled in the art will know how to remove the yeast hulls present in the beverage. This removal can typically be carried out by filtration. It is also possible to allow the hulls to settle at the bottom of the container holding the beverage during treatment, and to collect only the supernatant for consumption. When the beverage is wine, for example, it is possible to treat the wine directly in the barrel or vat by adding the yeast hulls. After treatment, the hulls naturally settle to the bottom of the barrel or vat. It is then possible to collect the settled hulls or to collect only the wine without them.

[0037] The present invention will now be illustrated by means of the examples below. Examples

[0038] Example 1: Organoleptic test

[0039] White wines contaminated with mousey taste were treated with 40 g / hL of SpringCell™ (yeast hull) and sulfite (SO2) with several contact times ranging from 2 to 24 days.

[0040] The treatment's effectiveness is evaluated using a sniffing method. This method standardizes the sensory test used to detect the presence of the mouse taste. This defect is generally not perceived when inhaling wine, i.e., via the orthonasal route, at the concentrations of APY, ETHP, and ATHP found in wines. These compounds are not sufficiently volatile at acidic pH levels. The oral pH is higher than that of wine, which explains why the defect is better perceived via the retronasal route. The test using a strip dipped in acid (sniffing) releases these molecules, making them detectable by simple inhalation.

[0041] Protocol:

[0042] - Soak a strip previously soaked in 0.1 M sodium hydroxide

[0043] - Dry

[0044] - Soak the strip in the wine to alkalize it, then

[0045] - Feel the strip.

[0046] Results'.

[0047] The results are presented in Figures 1 and 2.

[0048] As these figures show, the use of SpringCell™ at a dose of 40 g / hL reduces the perception of mousey taste in both Chenin Blanc matrices. The use of sulfite appears to have reduced the mousey taste in the short term but does not appear to eliminate it permanently, unlike yeast hulls.

[0049] The use of yeast hulls therefore makes it possible to reduce the perception of mouse taste in a lasting way, from two days of treatment.

[0050] Example 2: Chemical Test

[0051] During the second trial, a study was conducted to demonstrate whether the use of SpringCell™ would have the ability to chemically eliminate and / or reduce the molecules responsible for the mousey taste in wine.

[0052] Red wines were treated with either 40 g / hL of SpringCell™, or activated charcoal (positive control), or a commercial reference product for the elimination of musty taste (OTA, Anisols) with a contact time of 24 hours.

[0053] Protocol:

[0054] - Measurement of the decrease in ATHP concentration by chromatography in Gas-phase mass spectrometry (GC-MS). APY is not detectable in these tests, ETHP is not measured.

[0055] - Sensory evaluation of the perception of the defect (by orthonasal olfaction)

[0056] Results'.

[0057] The results are presented in Tables 1 and 2 below:

[0058] [Table 1]: Evaluation of ATPH concentration by GC-MS and intensity of taste of mouse via orthonasal route (Saint Chinian AGP 2022). Matrix 1* ATHP (w / L) Reduction (%) Mouse Taste Intensity** Control 23.6 NA 7 Active Carbon 13.7 41.95 3 SpringCell™ 20.5 13.14 4 Reference 23.5 0.42 3.6 * Saint Chinian AOP 2022 red wine currently aging ** 7 represents the maximum score for mouse taste intensity

[0059] [Table 2]: Evaluation of ATPH concentration by GC-MS and intensity of mousey taste via orthonasal route (Minervois AOP 2022). Matrix 2* ATHP (w / L) Reduction (%) Mouse Taste Intensity** Control 25.4 NA 3 Activated Charcoal 13.6 46.46 2 SpringCell™ 13.5 46.85 2.3 Reference 18.5 27.17 2.2 * Minervois AOP 2022 red wine bottled without sulfites ** 7 represents the maximum score for mouse taste intensity

[0060] A reduction of up to 45% in ATHP concentration was observed with the use of 40 g / hL of SpringCell™. The organoleptic perception of the treated wines confirmed the chemically observed reduction. The results are very promising, even with a treatment of only 24 hours. In view of the results of Example 1, it can be expected that these results will be improved after a longer treatment with yeast hulls.

[0061] The magnitude of the decrease in ATHP concentration is not necessarily correlated with that of olfactory perception.

[0062] The results demonstrate that SpringCell™ bark acts favorably to eliminate and / or chemically reduce the concentration of ATHP. This reduction corroborates that of the organoleptic perception.

Claims

Demands

1. Use of yeast hulls to prevent and / or reduce mousey taste defect in a fermented beverage.

2. A process for preparing a fermented beverage, said fermented beverage being preferably wine or beer, said process comprising a step in which a fermented and / or fermentable beverage is brought into contact with yeast hulls for a period of between 2 and 31 days, preferably between 7 and 24 days.

3. A process according to claim 2, wherein said process further comprises a step in which said yeast hulls are removed after being brought into contact with the beverage, preferably by filtration.

4. Use of yeast hulls to reduce the 2-acetyltetrahydropyridine (ATHP) content in a fermented and / or fermentable beverage.

5. Use according to claim 4, wherein the ATHP content is reduced by at least 10%, preferably at least 20%, even more preferably by at least 40% compared to the concentration observed in an untreated control fermented beverage.

6. Use according to any one of claims 1 and 4 to 5, wherein the yeast hulls are used at a concentration of 10 to 100 g / hL of beverage, preferably 20 to 60 g / hL of beverage, even more preferably 30 to 40 g / hL of beverage.

7. Use according to any one of claims 1 and 4 to 6, wherein said beverage is wine or beer, preferably the

8. wine. Use according to any one of claims 1 and 4 to 7, wherein said yeast barks are barks of Saccharomyces cerevisiae.

9. A process according to claim 2 or 3, wherein the yeast hulls are used at a concentration of 10 to 100 g / hL of beverage, preferably 20 to 60 g / hL of beverage, even more preferably 30 to 40 g / hL of beverage.

10. A method according to any one of claims 2, 3 and 9, wherein said yeast barks are barks of Saccharomyces cerevisiae.